description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to vehicle assembly tooling and more particularly to a tool for aligning a door striker to a vehicle body.
2. Discussion
Despite widespread use of striker positioning fixtures, variations in the various components which affect striker alignment have not eliminated the need to manually verify and adjust the alignment of a striker structure to a latch mechanism. Many of the tools currently in use are based on nominal dimensions and lack the capability to accurately adjust for normal manufacturing and assembly tolerances. Consequently, vehicle manufactures expend tremendous amounts of labor to measure the alignment between the striker and a latch mechanism, and to adjust the alignment of the striker when it is determined to be out of position.
To gage the alignment between a striker and a latch mechanism, a technician will repeatedly open and close a vehicle door to “feel” whether the striker is dragging on the latch mechanism. This process is heavily dependent upon the skill and experience to the technician and several iterations of unfastening, moving, refastening and rechecking are typically necessary to obtain satisfactory alignment.
Despite the effort that vehicle manufactures expand to achieve proper alignment between a striker and a latch mechanism, complaints regarding improperly aligned strikers are relatively frequent. Consequently, there remains a need in the art for tool for aligning a striker to a latch mechanism that provides more accurate results.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide a tool for coupling a striker to a structure in operative alignment with a latch mechanism.
It a more specific object of the present invention to provide a tool for aligning a striker to a latch mechanism which compensates for the variances in the manufacturing and assembly which affect striker alignment.
It is yet another object of the present invention to provide a method for aligning a striker to a latch mechanism.
A tool for coupling a striker to a first structure in operative alignment with a latch mechanism is provided. The tool includes a body locating portion and first and second locating portions. The body locating portion selectively couples the tool to a first structure, such as a vehicle body. The first location portion has a wedge member and a post member. The post member engages a latch ratchet in the latch mechanism and the tapered surfaces of the wedge member engage either the latch mechanism or the structure to which the latch mechanism is mounted. The second location portion includes a plate member, a positioning member and a positioning structure. The plate member has a first cavity which receives the positioning member. The plate member also has a slot which receives a leg member of the striker. The positioning structure is coupled to the plate member and slidable thereon along an axis parallel to the first cavity. The positioning structure adapted to contact a rear surface of the second structure. The positioning member disposed at least partially within the first cavity and coupled to the positioning structure such that axial movement of the positioning structure in a first axial direction causes positioning member to move an equal amount in an axial direction opposite the first axial direction. Contact between the positioning structure and the rear surface of the second structure causes the positioning member to move within the slot such that a tip of the positioning member defines a desired position of an outermost portion of the leg of the striker. A method for aligning a striker to a latch mechanism is also provided.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear view of a tool constructed in accordance with the teachings of the present invention;
FIG. 2 is a side view of a vehicle;
FIG. 3 is an enlarged view of a portion of the door shown in FIG. 2;
FIG. 4 is a top view of the striker shown in FIG. 2;
FIG. 5 is a front view of the tool of FIG. 1;
FIG. 6 is a left side view of the tool of FIG. 1;
FIG. 7 is a right side view of the tool of FIG. 1;
FIG. 8 is a top view of the tool of FIG. 1;
FIG. 9 is an exploded perspective view of the fixturing portion of the tool of FIG. 1;
FIG. 10A is a cut-away view illustrating a portion of the fixturing portion of the tool of FIG. 1;
FIG. 10B is a top view of a portion the fixturing portion shown in FIG. 10A;
FIG. 10C is a side view of the fixturing portion shown in FIG. 10B;
FIG. 11 is a side view of the tool of FIG. 1 in operative association with a latch mechanism;
FIG. 12 is a schematic diagram illustrating the controls portion of the tool of FIG. 1;
FIG. 13 is a top view of the tool of FIG. 1 in operative association with a vehicle door and vehicle body;
FIG. 14 is a top view of the tool of FIG. 1 in operative association with a vehicle body;
FIG. 15 is a partial section view of the tool of FIG. 1 as engaged to a striker structure;
FIG. 16 is a partial section view of the tool of FIG. 1 confining a striker structure to a desired location.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1 of the drawings, the assembly tool of the present invention is generally indicated by reference numeral 10 . Tool 10 is shown to include a body locating portion 14 , a fixturing portion 16 , a seal load simulation portion 20 and a controls portion 26 . Briefly, body locating portion 14 is operable for securing tool 10 to a vehicle body, fixturing portion 16 is opertable for locating a striker structure relative to a latch mechanism, seal load simulation portion 20 simulates the load which a seal exerts on the perimeter of a door assembly and controls portion 26 is operable for actuationg body locating portion 14 , fixturing portion 16 and seal load simulation portion 20 .
An exemplary vehicle 30 is illustrated in FIG. 2 through 4, and is shown to include a vehicle body 32 , a vehicle door assembly 34 and a striker structure 36 . Vehicle body 32 defines a structure having a door aperture 38 . Door assembly 34 is shown to be pivotably coupled to vehicle body 32 through a pair of hinges (not shown) which permit door assembly 34 to be positioned between a closed position, wherein door assembly 34 closes a door aperture 38 in vehicle body 32 , and an open position, wherein door assembly clears door aperture 38 . Door assembly 34 includes a conventional door structure 40 and a conventional latch mechanism 42 . Door structure 40 includes an outer panel 44 and a rear member 46 having a latch aperture 48 .
Latch mechanism 42 includes a housing 50 , a striker chute 52 and a latch ratchet 54 . Striker chute 52 is fixedly coupled to housing 50 and operable for locating latch mechanism 42 to latch aperture 48 . Latch ratchet 54 includes a striker aperture 56 which conventionally includes a first portion 58 and a second portion 60 , the function of which will be discussed in further detail, below. Latch ratchet 54 is rotatably coupled to housing 50 and operable between a unlatched condition wherein the striker aperture 56 is aligned between the striker chute 52 as shown in FIG. 3, and a latched condition wherein the striker aperture has been rotated relative to the striker chute 52 . Latch mechanism 42 is aligned to latch aperture 48 and fixedly coupled to door structure 40 such that striker aperture 56 is aligned to latch aperture 48 and striker chute 52 when latch ratchet 54 is positioned in the unlatched condition.
Striker structure 36 is illustrated as having a striker member 62 and a mounting plate 64 . Striker member 62 is generally U-shaped and fixedly coupled to mounting plate 64 such that the legs 66 of striker member 62 extend perpendicularly outwardly from mounting plate 64 . Mounting plate 64 includes a pair of fastener apertures 68 which permit mounting plate to be coupled to vehicle body 32 through a pair of conventional fasteners 70 . When installed and properly aligned, leg 66 a of striker member 62 is adapted to engage the second portion 60 of striker aperture 56 .
Body Locating Portion
Referring back to FIG. 1, and with additional reference to FIGS. 5 and 6, body locating portion 14 is operable for securing tool 10 to a vehicle body 32 . In the particular embodiment illustrated, body locating portion 14 includes an upper locating portion 132 , a spacer 133 and a lower locating portion 134 . Upper locating portion 132 includes a plate member 136 , an upper bumper structure 138 and an upper securing structure 140 . Upper bumper structure 138 is fixedly coupled to plate member 136 and includes a resilient bumper member 142 which is adapted to prevent tool 10 from scratching or marring the finish of vehicle body 32 when tool 10 is being used.
Upper securing structure 140 includes a suction cup member 146 which is conventional in construction and also fixedly coupled to plate member 136 . Suction cup member 146 is adapted to secure upper locating portion 132 to vehicle body 32 when upper securing structure 140 is placed proximate a predetermined portion of vehicle body 32 and vacuum pressure which exceeds a predetermined minimum pressure is applied to suction cup member 146 . Suction cup member 146 is coupled to controls portion 26 through a vacuum hose 148 .
Lower locating portion 134 includes a plate member 150 , a pair of lower bumper structures 152 and a lower securing structure 154 . Each of the lower bumper structures 152 are fixedly coupled to plate member 150 and include a resilient bumper member 156 which is adapted to prevent tool 10 from scratching or marring the finish of vehicle body 32 when tool 10 is being used.
Lower securing structure 154 includes a suction cup member 158 which is conventional in construction and also fixedly coupled to plate member 150 . Suction cup member 158 is adapted to secure lower locating portion 134 to vehicle body 32 when lower securing structure 154 is placed proximate a predetermined portion of vehicle body 32 and vacuum pressure which exceeds a predetermined minimum pressure is applied to suction cup member 158 . Suction cup member 158 is also coupled to controls portion 26 through vacuum hose 148 .
Spacer 133 is fixedly coupled to plate members 136 and 150 . Spacer 133 is operable for spacing plate member 136 apart from plate member 150 a predetermined distance to permit body locating portion 14 to conform to a desired portion of vehicle body 32 .
Fixturing Portion
In the particular embodiment illustrated fixturing portion 16 includes a bracket structure 210 , a bumper structure 212 , a backing plate 214 , a door location portion 216 and a latch locating portion 218 . Bracket structure 210 couples fixturing portion 16 and seal load simulation portion 20 to body locating portion 14 . Bracket structure 210 is generally L-shaped and formed from a suitable structural material such as aluminum. Bumper structure 212 is operable for spacing bracket structure 210 apart from rear member 46 a predetermined distance. Preferably, bumper structure 212 simulates a portion of vehicle body 32 when door assembly 34 is placed in the closed position. Bumper structure 212 is formed from a wear resistant plastic material, such as DELRIN®, which is adapted to prevent tool 10 from scratching or marring the finish of door structure 40 when tool 10 is being used.
Backing plate 214 is fixedly coupled to bracket structure 210 and serves as a foundation for the door and latch locating portions 216 and 218 . Backing plate 214 is preferably unitarily formed from a wear resistant plastic material, such as DELRIN®, which is adapted to prevent tool 10 from scratching or marring the finish of door structure 40 when tool 10 is being used. Backing plate 214 is an elongated member having a first portion 224 adapted for mounting door location portion 216 and a second portion 226 which is offset laterally from the first portion 224 and adapted for mounting latch locating portion 218 .
With additional reference to FIG. 7, first portion 224 includes a first cavity 230 in the rear surface 232 of backing plate 214 . Second portion 226 includes a second cavity 240 located in the outward end of backing plate 214 , a third cavity 244 located in the top surface 246 of backing plate 214 , a fourth cavity 248 located in the bottom surface 250 of backing plate 214 , a spring aperture 252 , a pair of fastener apertures 254 , a pair of magnet apertures 256 and a slotted aperture 258 . Slotted aperture 258 is adapted to receive the legs 66 of striker structure 36 . Third and fourth cavities 244 and 248 intersect second cavity 240 . Backing plate 214 also includes a plurality of pin apertures 260 and fastener apertures 262 .
Door location portion 216 includes a striker simulator 264 and a striker wedge 266 . Striker simulator 264 is identical to striker structure 36 and need not be discussed in detail. Briefly, striker simulator 264 includes a generally U-shaped striker member 268 and a mounting plate 270 . The legs 272 are fixedly coupled to mounting plate 270 . Mounting plate 270 includes a pair of fastener apertures 274 . Striker simulator 264 is mounted in first cavity 230 and fasteners 276 are inserted through apertures in backing plate 214 , striker simulator 264 and bracket structure 210 . Nuts 278 are threadably engaged to fasteners 276 to secure both backing plate 214 and striker simulator 264 to bracket structure 210 .
The cross-section of striker wedge 266 is generally shaped as a truncated triangle having a base 280 and a tip 282 . A U-shaped striker slot 284 extends from tip 282 toward base 280 and is sized to receive leg 272 b of striker simulator 264 . Striker wedge 266 is fixedly coupled to backing plate 214 such that leg 272 b of striker simulator 264 is partially disposed within striker slot 284 . The sides 286 of striker wedge 266 are adapted to engage striker chute 52 when striker simulator 264 is engaged to latch ratchet 54 . As such, striker wedge 266 is operable for limiting the rotation of tool 10 about latch mechanism 42 when striker simulator 264 is engaged to latch ratchet 54 .
Latch locating portion 218 includes a latch positioning mechanism 290 and a latch clamp 292 . In the particular embodiment illustrated, latch positioning mechanism 290 includes a positioning member 294 , a link member 296 , a pivot pin 330 , first and second coupling pins 332 and 356 , respectively, a link positioning structure 304 , a pair of positioning guides 306 and a stop mechanism 308 . Positioning member 294 is a cylindrical rod having a magnetic tip 310 at a first end and a link connecting portion 312 at a distal end. Magnetic tip 310 is machined to match the profile of leg 272 a . Link connecting portion 312 includes a link slot 314 extending along an axis parallel top surface 246 and a connector aperture 316 extending along an axis perpendicular to link slot 314 . Positioning member 294 is disposed at least partially within second cavity 240 and operable for adjusting the striker structure 36 in a cross-car direction as will be discussed in detail below.
Link member 296 is disposed within third cavity 244 and includes a pivot aperture 324 and first and second slotted pin apertures 326 and 328 , respectively. Pivot pin 330 extends through pivot aperture 324 and a pin aperture 260 a in backing plate 214 and pivotably couples link member 296 to backing plate 214 . A first end of link member 296 is disposed in link slot 314 at the distal end of positioning member 294 . First coupling pin 332 extends through a pin slot 260 b in backing plate 214 , the connector aperture 316 in positioning member 294 and first slotted pin aperture 326 to couple link member 296 and positioning member 294 . Rotation of link member 296 about pivot pin 330 is therefore operable for causing positioning member 294 to extend from or retract into second cavity 240 . The end distal the first end of link member 296 extends outwardly from third cavity 244 above top surface 246 .
In FIGS. 8 and 9, link positioning structure 304 includes an abutting member 340 , a bumper structure 342 and a handle member 344 . Abutting member 340 is generally flat and adapted to slide along the top surface 246 of backing plate 214 . Abutting member 340 includes a link positioning slot 348 , a link coupling aperture 350 and first and second guide slots 352 and 354 , respectively. Abutting member 340 is placed over third cavity 244 such that the distal end of link member 296 extends into link positioning slot 348 . Second coupling pin 356 is placed through link coupling aperture 350 and the second slotted pin aperture 328 to couple link member 296 to abutting member 340 .
Each of the positioning guides 306 includes a threaded stud 360 , a washer 362 and a locking nut 364 . Threaded studs 360 are placed through each of the link positioning slots 352 and 354 and threadably engaged to backing plate 214 . Washer 362 and locking nut 364 are employed to confine the vertical movement of abutting member 340 while permitting abutting member 340 to move freely in a cross-car direction. Movement of abutting member 340 in the cross-car direction therefore causes link member 296 to pivot about pivot pin 330 .
Bumper structure 342 includes a resilient bumper member 366 which is adapted to contact the rear surface 44 a of outer panel 44 (shown in FIG. 2 ). Bumper structure 342 is adjustably coupled to link member 296 which permits the distance between the end of bumper member 366 to the centerline of the link coupling aperture 350 (indicated by dimension “d”). Handle member 344 is fixedly coupled to abutting member 340 and is adapted to permit an operator employing tool 10 to slide abutting member 340 along top surface 246 so that bumper member 366 contacts rear surface 44 a.
In FIGS. 9 and 10A, stop mechanism 308 is operable for restraining the movement of positioning member 294 in first cavity 230 . Stop mechanism 308 includes a cylinder assembly 370 , a resilient stop member 372 , a protective sleeve 374 and a pair of fasteners 376 . Cylinder assembly 370 is a conventional double-acting pneumatic cylinder, such as a 01-05 cylinder manufactured by Bimba Manufacturing Company, having a cylinder housing (not specifically shown), a piston (not specifically shown) and a rod 378 . Cylinder assembly 370 is coupled to controls portion 26 and maintained in a condition such that rod 378 is normally retracted. Resilient stop member 372 is coupled to the distal end of rod 378 .
Protective sleeve 374 includes a generally hollow body portion and a flange portion (not specifically shown). Cylinder assembly 370 is disposed within protective sleeve 374 . Fasteners 276 extend through the flange portion of protective sleeve 374 into bottom surface 250 to fixedly but removably couple cylinder assembly 370 and protective sleeve 374 to backing plate 214 . In coupling cylinder assembly 370 to backing plate 214 , cylinder assembly 370 is positioned such that rod 278 extends into fourth cavity 248 . Protective sleeve 374 prevents the housing of cylinder assembly 370 from moving in a direction away from backing plate 214 . Protective sleeve 374 is fabricated from a wear resistant plastic material, such as DELRIN®, which is adapted to prevent tool 10 from scratching or marring the finish of door structure 40 when tool 10 is being used.
Latch clamp 292 includes a first clamp structure 400 , a second clamp structure 402 and a pair of guides 406 . First clamp structure 400 includes a base portion 410 , first and second fork members 412 and 414 and a stop member 372 . Base portion 410 includes a pair of slotted guide apertures 420 , a pin aperture 422 and a slotted aperture 424 . First and second fork members 412 and 414 each extend generally perpendicularly outward from base portion 410 . Stop member 372 is a generally flat member which is fixedly but removably coupled to the distal ends of first and second fork members 412 and 414 .
Guides 406 are illustrated as being conventional shoulder screws 426 . Shoulder screws 426 are inserted through each of the slotted guide apertures 420 and threadably engaged to backing plate 214 . First coupling pin 332 extends through backing plate 214 and into pin aperture 422 to couple positioning member 294 and first clamp structure 400 together. Movement of link positioning structure 304 is therefore operable for moving positioning member 294 as well as first clamp structure 400 . The shoulder portions 426 a of shoulder screws 426 are operable for guiding first clamp structure 400 along an axis parallel to positioning member 294 .
With additional reference to FIG. 8, second clamp structure 402 includes a clamp arm structure 430 with a clamp arm 432 and a pair of pin inserts 434 . Clamp arm structure 430 is pivotably coupled to first and second fork members 412 and 414 and positionable between a closed position and an open position. Clamp arm structure 430 is biased toward the open position by a compression spring 435 . Stop member 372 inhibits clamp arm structure 430 from pivoting away from backing plate 214 beyond a predetermined point. Each of the pin inserts 434 contacts a magnet 436 disposed within magnet apertures 256 when clamp arm structure 430 is placed in the closed position. Magnets 436 are operable for maintaining clamp arm structure 430 in the closed position.
With renewed reference to FIG. 6, the tip 440 of clamp arm structure 430 is sized to extend into slotted striker aperture 56 when clamp arm structure 430 is positioned in the closed position. Tip 440 is configured to push striker structure 36 toward the magnetic tip 310 of positioning member 294 when clamp arm structure 430 is closed and a striker structure 36 is disposed within slotted striker aperture 56 .
Seal Load Simulation Portion
In FIGS. 1 and 7, seal load simulation portion 20 includes a bumper structure 498 and a pneumatic cylinder assembly 500 , such as a F04-1 cylinder manufactured by Bimba Manufacturing Company, having a cylinder housing 502 and a rod 504 . Cylinder assembly 500 is normally maintained in a retracted condition wherein rod 504 is retracted within cylinder housing 502 . Cylinder housing 502 is coupled to bracket structure 210 and oriented such that bumper structure 498 contacts the rear surface 44 a of outer panel 44 when rod 504 has been extended. Cylinder assembly 500 is operable for exterting a force on rear surface 44 a which approximately simulates the load which would be generated through the compression of a resilient seal (not specifically shown) surrounding door aperture 38 when door assembly 34 is positioned in the closed position.
Controls Portion
Controls portion 26 is schematically illustrated in FIG. 16 as including an inlet port 600 , a handle assembly 602 , a vacuum pump 604 , first and second directional valves 606 and 608 , respectively, a vacuum switch 610 and a plurality of fluid conduits 612 . With additional reference to FIG. 1, handle assembly 602 includes a handle member 344 and a plurality of push-button actuated, spring-return directional valves 622 a , 622 b and 622 c . Each of the first and second directional valves 606 and 608 are 2 position, 4-way, detented, pilot-operated valves.
Tool Operation
An air line is coupled to tool 10 and provides compressed air to inlet port 600 . Conduits 612 a , 612 b , 612 c and 612 d direct the compressed air is directed to vacuum switch 610 , first and second directional valves 606 and 608 and push-button valves 622 b and 622 c . The valve body of first directional valve 606 is positioned in a first valve position which provides a flow path to the return side of cylinder assembly 500 , causing the rod of cylinder assembly 500 to remain in a retracted state. Similarly, the valve body of the second directional valve 608 is positioned in a first valve position which provides a flow path to the return side of cylinder 370 , causing the rod of cylinder assembly 370 to remain in a retracted state.
Striker structure 36 is placed proximate vehicle body 32 and fasteners 70 are inserted through fastener apertures 68 and threadably engaged to vehicle body 32 . Fasteners 70 are not tightened to produce a clamping force at this point and thereby only loosely couple striker structure 36 to vehicle body 32 to permit tool 10 to position striker structure 36 in a desired manner.
In FIG. 11, tool 10 is placed against door assembly 34 and striker simulator 264 is engaged to latch mechanism 42 (i.e., the leg 272 a of striker simulator 264 is engaged into the first portion 60 of latch ratchet 54 and the sides 286 of striker wedge 266 engage striker chute 52 ). Door assembly 34 is pivoted toward the closed position until the legs 66 of the striker structure 36 are received into the slotted aperture 258 and the suction cup members 146 and 158 contact vehicle body 32 as shown in FIG. 13 .
Push-button valve 622 b is actuated and provides a flow path for the compressed air through conduit 612 e to provide pilot pressure to first directional valve 606 . In response to the pilot pressure, the valve body of first directional valve 606 shifts into a second valve position permitting compressed air to flow to actuate vacuum pump 604 and exhausting the return side of cylinder assembly 500 to the atmosphere.
Once actuated, vacuum pump 604 is operable for generating negative pressure and tends to draw air from conduits 612 f and 612 g . As suction cup members 146 and 158 are engaged to vehicle body 32 , air is inhibited from entering into conduit 612 f causing the accumulation of negative pressure in conduits 612 f and 612 g . After a predetermined amount of negative pressure has accumulated in conduit 612 g , vacuum switch 610 opens, releasing compressed air to conduits 612 h and 612 i to supply compressed air to push-button valve 622 a and to the extend side of cylinder assembly 500 . The rod of cylinder assembly 500 extends in response thereto, causing bumper structure 498 to contact rear surface 44 a and exert a simulated seal load. The simulated seal load is transmitted through tool 10 and door assembly 34 and simulates the load generated when door assembly 34 is placed in the closed position.
As illustrated in FIG. 15, positioning member 294 is not in contact with the leg 66 a of striker structure 36 . Handle member 344 is moved in a direction away from vehicle 30 until bumper member 366 contacts rear surface 44 a , thereby causing abutting member 340 to rotate link member 296 about pivot pin 330 and move positioning member 294 in slotted aperture 258 to a desired positioning member location (i.e., the outermost position of the leg 66 a of the striker structure 36 ). As latch clamp 292 is coupled to positioning member 294 , rotation of link member 296 about pivot pin 330 causes latch clamp 292 to move in the same direction and by an equivalent magnitude. Push-button valve 622 a is next actuated to apply pilot pressure to second directional valve 608 . In response to the pilot pressure, the valve body of second directional valve 608 shifts into a second valve position permitting compressed air to flow to the extend side of cylinder assembly 370 and venting the return side of cylinder assembly 370 to atmosphere. The rod of cylinder assembly 370 extends in response thereto and causes stop member 372 to fixedly but releasably lock positioning member 294 in the desired positioning member location.
Latch mechanism 42 is next actuated to release striker simulator 264 . Door assembly 34 is rotated toward the open position to permit access to striker structure 36 . As illustrated in FIGS. 14 and 16, clamp arm structure 430 is next pivoted toward striker structure 36 . Tip 440 is contoured to contact striker structure 36 and push it toward the magnetic tip 310 of positioning member 294 . Magnets 436 bias clamp arm structure 430 toward the closed position, trapping striker structure 36 between magnetic tip 310 and tip 440 . A conventional fastening tool is then utilized to tighten fasteners 70 .
Push-button 622 c may be actuated at any time and applies a pilot pressure to first and second directional valves 606 and 608 which causes their respective valve bodies to shift to their respective first valve positions. In response thereto, compressed air is provided to the return sides of cylinder assemblies 500 and 370 , the extend sides of cylinder assemblies 500 and 370 is vented to atmosphere, and vacuum pump 604 is vented to atmosphere. Suction cup members 146 and 158 release from vehicle body 32 . Clamp arm structure 430 is rotated away from striker structure 36 and handle member 344 is moved in a direction toward vehicle 30 to ready tool 10 for its next use.
While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the description of the appended claims. | A tool for aligning a striker to a latch mechanism is provided. The tool includes a body locating portion and first and second locating portions. The body locating portion selectively couples the tool to a first structure, such as a vehicle body. The first location portion has a wedge member and a post member. The post member engages a latch ratchet in the latch mechanism and the tapered surfaces of the wedge member engage either the latch mechanism or the structure to which the latch mechanism is mounted. The second location portion includes a plate member, a positioning member and a positioning structure. The plate member has a first cavity which receives the positioning member. The plate member also has a slot which receives a member of the striker. The positioning structure is coupled to the plate member and slidable thereon along an axis parallel to the first cavity. The positioning structure adapted to contact a rear surface of the second structure. The positioning member disposed at least partially within the first cavity and coupled to the positioning structure such that axial movement of the positioning structure in a first axial direction causes positioning member to move an equal amount in an axial direction opposite the first axial direction. Contact between the positioning structure and the rear surface of the second structure causes the positioning member to move within the slot such that a tip of the positioning member defines a desired position of an outermost portion of the leg of the striker. A method for aligning a striker to a latch mechanism is also provided. | 4 |
RELATED APPLICATION
This application claims the priority date of U.S. provisional patent application Ser. No. 60/488,650 filed on Jul. 19, 2003.
BACKGROUND OF THE INVENTION
This invention relates generally to intumescent, ceramic silicate fire retardant coatings, which can be used to insulate substrates such as structural steel or wood materials used in buildings to protect the substrates from fires and more specifically, to the intumescent ceramic silicate liquid binder in which is incorporated intumescent, ceramic, silicate particles.
Hydrated metal silicates are known fire-proofing materials and are extensively employed in building construction to insulate apertures and passages in buildings against the passage of fire and smoke. Under the high temperatures existing during a fire, the water of hydration of the metal silicates are driven off causing the composition to expand (intumesce) by up to forty times its original volume forming a foam structure that insulates the building against heat generated by the fire. The foaming pressure of the metal silicate particles helps to seal apertures and passages in building structures making these fireproofing materials useful in fire-stops, as described in U.S. Pat. No. 4,364,210 to Fleming et al., which is hereby incorporated by reference in its entirety. In addition, the preparation of intumescent silicates is described in U.S. Pat. No. 4,521,333 to Graham et al., which is hereby incorporated by reference in its entirety.
SUMMARY OF THE INVENTION
A fire retardant, intumescent, ceramic coating composition comprising an aqueous ceramic intumescent binder, intumescent ceramic particles, mineral fibers and a wetting agent is provided. The intumescent ceramic binder comprises a mixture of a liquid alkali metal silicate, a borate salt, mineral fibers and a wetting agent. The coating provides enhanced intumescence and insulative properties suitable for application to structural steel and wood building materials.
A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth illustrative embodiments that are indicative of the various ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWING
For a better understanding of the invention, reference may be had to preferred embodiments shown in the following drawing in which:
FIG. 1 is a graph depicting the temperature of steel bars, which are exposed to external furnace temperatures of 1800° F. and which having varying thicknesses of an intumescent coating, as a function of time and temperature; and
FIG. 2 is a graph depicting the temperature of a piece of drywall, where an intumescent coating has been applied to a front side of the drywall and the front side of the drywall is exposed to a flame temperature of 2000° F., and where the temperature is being taken at a back side of the drywall.
DETAILED DESCRIPTION
A unique composition has been developed by adding to a water soluble alkali silicate, particles of the same water soluble alkali silicate, which have been combined with a borate compound and then, dried and pulverized into various particle sizes. The composition may be further enhanced by incorporating mineral fibers and a soluble, low foaming, wetting agent. The mineral fibers strengthen the coating and the wetting agent increases adhesion to the metal or wood substrate.
Examples of useful water soluble alkali silicates are sodium silicate, lithium silicate and potassium silicate, however, it is preferred that sodium silicate be used. Sodium silicate has a silica/soda weight ratio of 3.22. It should be understood by those with skill in the art, however, that sodium alkali silicates with different silica/soda weight rations may also be used. These intumescent particles also control the uniformity, stability and height of the intumescence upon exposure to a fire.
Examples of borate compound are borax, calcium borate, magnesium borate and zinc borate, with zinc borate being preferred. Examples of mineral fibers include alkali stable fiberglass, wollastonite and mica. It should also be appreciated that other mineral fibers may be used without departing from the scope of this invention. The preferred wetting agent is sodium 2-ethylhexyl sulfate, but other equivalent wetting agents may also be used.
EXAMPLE 1
A coating was prepared and applied to steel bars for testing in a small lab furnace. The coating was made by first preparing the particles in the following manner. A finely ground zinc borate was added to a first sodium silicate solution with a silica/soda weight ratio of 3.22, the zinc borate comprising about three percent (3%) by weight of the combination of the zinc borate and the first sodium silicate solution. The zinc borate was added with high shear mixing. The compound was mixed for five minutes, spread out in a thin layer on a polyethylene sheet, air dried to a constant weight and pulverized into particles of 500 microns or less. The pulverized particles were added to a second sodium silicate solution with a silica/soda weight ratio of 3.22, the pulverized particles comprising about fifteen percent (15%) by weight of the combination of the pulverized particles and the second silicate solution. The second sodium silicate solution is further comprised of one percent (1%) 2-ethylhexyl sulfate and fifteen percent (15%) wollastonite with an aspect ratio of 15:1 (length to diameter) being preferred. Wollastonite fibers of different aspect ratios may also be used. The coating was mixed for ten minutes then applied at various thicknesses to steel bars containing a thermocouple inserted into the center of the bar. After the coated bars were air dried for two weeks, they were placed in a laboratory furnace and fire tested. FIG. 1 is a graph that compares the performance to two thicknesses of the intumescent ceramic coating to an uncoated steel bar. The failure point at which the steel looses its structural strength is between 950° F. and 1100° F. The graph shows that a coating thickness of 350 mils of the intumescent coating described herein protects the steel from reaching its failure point for over two hours after being subjected to an external furnace temperature of 1800° F.
EXAMPLE 2
A coating was prepared and applied to a piece of drywall (not shown) having a first side and a second side for testing in a small lab furnace. The same coating that was applied to the steel bars in Example 1 was applied to the first side of the drywall. The first side of the drywall was then exposed to a flame temperature of 2000° F., while the temperature of the drywall was measured at the second side of the drywall. FIG. 2 is a graph depicting the temperature of the drywall taken at the second side of the drywall.
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangement disclosed is meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any equivalents thereof. | A fire retardant, intumescent, ceramic coating composition comprising an aqueous ceramic intumescent binder, intumescent ceramic particles, mineral fibers and a wetting agent is described. The intumescent ceramic binder comprises a mixture of a liquid alkali metal silicate, mineral fibers and a wetting agent. The coating provides enhanced intumescence and insulative properties suitable for application to structural steel and wood building materials. | 2 |
The U.S. Government has rights in this invention pursuant to Contract No. DE-AC09-76SR00001 between the U.S. Department of Energy and E. I. du Pont de Nemours and Company, Inc. (41 CFR 9-9.109-6(i) (5) (ii) (B).
FIELD OF THE INVENTION
The present invention relates to cooling towers by means of which wind forces are harnessed to bring ambient air into intimate contact with effluent water discharged at high temperature from a production facility and, as an ancillary benefit, to generate power, to cooling of the effluent water being required to permit its return to the natural stream, or river, from which it was obtained without impairing the ecological balance.
BACKGROUND OF THE INVENTION
Towers of this type may be several hundred feet in height with a diameter at the base being somewhat greater than one-third the height of the tower. Effluent water is pumped into the interior of the tower at an intermediate level is thereby brought into contact with an upwardly flowing draft of atmospheric air developed by natural wind current which are introduced at the base of the tower.
Contact between the air and water in the tower is maintained in one of two ways. The tower may be filled with rock fragments or may include a lattice-work matrix through which the air current passes to evaporate and cool the water which is continually sprayed on the rock or matrix surfaces. Due to the restriction in the flow of air only a minimum of power can be generated by wind turbines placed in the air stream.
Generally, when the generation of power as an ancillary benefit is considered, an unimpeded air draft in the tower is required and water is supplied by nozzles arranged around the interior wall of the tower near the base to minimize the amount of water lost as evaporated vapor.
In one form of cooling tower of this type, a wind turbine using propellor blades rotating on a vertical axis was placed in the exit plane of the tower. However, it was found that the blades interferred with the tower's natural drafting ability especially when the velocity of the air draft at the exit plane was in the range of 12-15 ft/sec or less.
It has also been suggested to use a tower having a hyperbolic vertical wall configuration in which the horizontal cross-section converges upwardly from the base to an intermediate level and then diverges to the exit plane at the top, with the vertically rotating blades of the wind turbine located at the narrow throat portion to maximize the increased air velocity at that level since power is proportional to the air velocity cubed, and additional power should be obtained by the vortex core formed in the exhaust draft above the turbine. However, the reduction in throat diameter needed to increase the air velocity resulted in an excessive air flow pressure drop which reduced the air flow. The result was that a minimal increase in power output was accompanied by excessive costs in additional wind turbine support structures.
U.S. Pat. No. 4,031,173 issued to Paul Rogers discloses a tower having an arrangement of blade-like surfaces mounted on the exterior of the tower for rotation about the tower in a horizontal plane in response to wind movement. Each of the blades is adjustably mounted in a framework carried on rollers supported on a track that surrounds the tower. The complexity of this design would tend to make it commercially impractical.
U.S. Pat. No. 4,070,131, issued to James T. Yen discloses two forms of towers in which a vortex core air flow with a wind turbine rotating in a horizontal plane located at the base of the tower. In one form of the invention the tower wall consists of a series of narrow vertical vanes mounted for individual rotation under the control of a wind direction sensor for the purpose of introducing wind into the tower with a swirling movement regardless of the direction from which the wind is arriving.
In a modified form a single wind inlet includes a helical passage at the base of the tower to introduce air with a swirling motion and the entire tower and single air inlet are mounted on a rotary platform for movement, under control of a wind direction sensor, to place the inlet in correct position at all times. Nevertheless, the concept of building a tower several hundred feet tall and nearly as wide at its base with the walls consisting of automatically pivoted narrow air-directing vases or of building a solid-walled tower of that size and mounting it and its attendant air inlet and power generating mechanisms on a rotatable platform are not presently commercially appealing. It should also be mentioned that no specific provision for cooling water is disclosed in this patent.
BRIEF SUMMARY OF THE INVENTION
According to a paper by Karl H. Bergey, "The Lanchester--Betz Limit" published in the Journal of Energy, Vol. 3, No. 6, November-December 1979 pp. 382-384, the maximum possible power obtained from a windmill is calculated from: ##EQU1## which can be written as ##EQU2## where P is the power obtained N is the windmill efficiency
Ma is the mass flow rate
Va is the air velocity
Since typical windmills have similar efficiencies (theoretical maximum is 0.59) and large scale air density control is not practical, the controlling factor on windmill power is a combination of air velocity and windmill blade area. Increased power production results from increasing either the blade diameter or the air velocity. However, rotor stress considerations limit the blade diameter and maximum air velocity.
The theoretical maximum efficiency of 0.59 is valid for only those windmills which remove kinetic energy from the air stream. These windmills are typical of those found on rural farms. Recent research has increased windmill efficiency by recovering a portion of the air stream pressure energy which is far greater than the air stream kinetic energy. This research involves methods of reducing the windmill back pressure. The difference between inlet and output pressures is then converted into usable energy. For example, the pressure equivalent of a 30 mi/hr wind is only 0.016 psia. This pressure is over 60 times smaller than the available energy in a 1 psi inlet and outlet pressure difference.
A cooling tower is judged by its effectiveness in cooling a given water flow. Heat transfer consideration indicate this cooling to be a function of air flow, tower height to which the water is pumped, ambient air temperature and humidity, and the water path in the tower. Since ambient air conditions cannot be altered and water inside a cooling tower traditionally splashes around a beam-matrix-type fill material from its entry point to the ground, a given cooling capacity is dictated by tower size. The larger the tower diameter, the larger the air flow. Also, for a given tower diameter, the air flow is increased by increasing the tower height. The maximum air flow is determined by balancing the maximum theoretical draft, measured in inches of water, with the cooling tower air flow friction losses; the draft being determined by the equation
Draft=H/5.2(1/υ.sub.amb -1/υ.sub.a.sbsb.E) (3)
where H is the cooling tower height
υ amb is ambient air specific volume
υ a .sbsb.E is the air specific volume at the cooling tower exit plane
The specific volume diffference in Equation 3 are equivalent to the Boussinesq approximation discussed in H. Tennekes and J. L. Lumley's text "A First Course in Turbulence", MIT Press, Cambridge, Mass., 1972, p. 136, in which density differences are created by temperature differences.
A vortex flow pattern can enhance cooling tower effectiveness for two reasons. First, the vortex generates larger air velocities which increases the heat transfer between the ambient air and water. Second, the swirling motion of the vortex flow has a tendancy to maintain its flow pattern for some distance above the tower height, thereby increasing the theoretical draft in Equation 3. By maintaining this swirling motion, the tower plume does not develop as rapidly as for a typical natural draft tower.
The vortex has a tendency to maintain its swirling motion upon exiting the tower because of the Helmholtz vorticity concept as set out in I. G. Curries "Fundamental Mechanics of Fluids" McGraw-Hill, New York, 1974, pp. 46-48. These concepts state that vorticity is related to circulation, a conserved quantity, by ##EQU3## where Γ represents circulation
A is the area
ω is the vorticity vector
n is the unit normal vector
Since the flow's circulation upon leaving the cooling tower is fixed, the plume slowly develops because the flow vorticity resists atmospheric diffusive action. In the typical cooling tower there is no flow vorticity and the flow is less resistive to atmospheric diffusive action.
The effective increase in tower height resulting from a vortex flow pattern can also enhance windmill power production. This occurs because the increased effective tower height results in a larger air flow and air velocity through the tower. Equation 2 shows the relationship between these flow parameters and power production.
It is apparent that for the tower to be able to cool effectively and operate a windmill in the exit plane, the air flow exit velocity must be increased. To increase this velocity, the fill material in a typical cooling tower is not used and the water to be cooled is sprayed into the tower. Since the pressure drop for air moving upward past water droplets is less than the typical cooling tower in which air flows through the beam matrix-type fill material, greater air velocity and mass flow is possible for this type of water-air heat transfer.
The windmills are located around the tower base periphery for a combination of reasons. First, standard windmills can be used because the blades are perpendicular to the ground. Second, relatively simple installation is possible when compared to the windmill configuration in which turbines rotating about a vertical axis are placed in the tower itself. Third, the windmills are physically located to avoid interfering with the heat transfer processes between the water addition and ground levels. To obtain the desired cooling tower effectiveness, the water droplets need to drop from the water addition level to the ground. If horizontally rotating windmills are placed at the ground level in the plane of the tower wall the water droplets in the tower cross-sectional area would not be uniformly distributed and poor water cooling would result. Looking at Equation 3, poor water cooling results in a smaller theoretical tower draft which translates into a smaller tower air flow. Using Equation 2, the smaller flow results in smaller power generation.
To avoid this problem the windmills are located at a distance outwardly from the base of the tower and their exhausts are directed by means of horizontal passages to the tower base. These passages are desireable to prevent the wake of one windmill from interfering with the performance of adjacent windmills. This air flow path can be optimized to increase windmill power production by providing one or more additional outside air injection slots in the passages downstream from each of the windmills. This results in a reduced windmill exhaust pressure to provide increased power production.
By arranging the windmills about the entire periphery of the base of the tower with their air inlets facing outwardly it becomes unnecessary to mount the windmills or air inlets on rotating structures with the concomitant necessity for providing air direction sensors and controlled power devices for continually shifting the air inlets to conform to changes in wind direction. Considering the array of air inlets as a whole they constitute an omnidirectional air inlet for the cooling tower.
By further arranging the air passages in a symmetrical pattern in which each passage introduces the exhaust air from a windmill into the base of the tower at an angle with respect to a tower radius, a swirling action is imparted which develops a vortical upward flow in the tower.
It is therefore an object of the invention to provide a water cooling tower having an unobstructed interior with an omnidirectional fixed air inlet means at the base.
Another object is to provide a water cooling tower which includes wind turbine power generating means located outside of the tower itself to avoid interference with either the flow of air in the tower or the interactive pattern of contact between water to be cooled and the cooling air.
A further object is to provide a cooling tower having an unobstructed vortex air flow pattern in the tower to increase the tower efficiency and including wind turbine power generating means operated by the air flow thus produced.
Still another object is to provide tower means for confining and upwardly directing currents of atmospheric air by means of which effluent water may be cooled and power may be generated by conventional windmills.
A still further object is to provide air inlet means for introducing atmospheric air into the base of a water cooling tower by means of symmetrically arranged horizontally directed air passages in which conventional windmills are installed, the efficiency of the windmills being increased by the introduction of additional atmospheric air at points downstream of the windmills.
Yet another object is to provide a wind operated water cooling and power generating tower having air inlet means at its base arranged to introduce atmospheric air into the base in a helical direction to generate a solid core vortex flow air discharge path in the tower.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, FIG. 1 is a cross-sectional elevation, taken on the line 1--1 of FIG. 2, of a preferred form of water cooling and power generating tower in accordance with this invention;
FIG. 2 is a horizontal cross-section taken on the line 2--2 of FIG. 1;
FIG. 3 is a perspective view, on a greatly enlarged scale, of one of the air inlet passages;
FIG. 4 is a fragmentary longitudinal cross-section, on a still more enlarged scale, of the inlet end of an air passage, showing the mounting of a wind turbine;
FIG. 5 is a graphical representation of the effect of introducing additional air into an air passage;
FIG. 6 is a schematic representation of action of the plume rising from the outlet of a tower operating under natural draft, and;
FIG. 7 is a schematic representation of the effects of a vortex draft as it leaves the exit plane of a cooling tower.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, a large vertical cooling tower is indicated generally by numeral 10, said tower being provided with omnidirectional atmospheric air inlet means at its base, indicated generally by numeral 11, said air inlet means including wind turbine actuated power generating means, indicated generally by numeral 12. Appropriate nozzle means, indicated generally by numeral 13, is provided for introducing water into the interior of the tower to be cooled by the flow of air from inlet means 11 upwardly to the outlet opening 14 at the top of the tower.
The omnidirectional air inlet means 11 preferably comprises a series of helically directed horizontally extending similar passages 15 disposed about the entire exterior periphery at the base of tower 10. The inlet ends 16 of each of the passages are located radially outwardly of the tower, so that at any given time these inlets will collect a flow of atmospheric air, regardless of the wind direction.
Within each of the passages 15 a wind operated power generating means, such as a windmill 17 is mounted for customary rotation about a horizontal axis and, in order to confine the air flow for maximum effectiveness in driving the windmill, the inlet end 16 is preferably circular in outline and may be inwardly constricted, as at 18, to provide a venturi effect. The hub of the windmill may include means for generating electrical power such as a generator, or alternator 19, mounted in the passage by means of two or more radially extending arms 20.
Due to the fact that the temperature of the air is increased as a result of work performed in turning the windmill the cross-sectional area of the passage 15 is progressively increased in the direction down stream from windmill 17 so as not to impede the flow or create back pressure. In addition it may be desirable to introduce additional outside air into the passage to overcome boundary layer effects. This additional air could be introduced by the provision of one or more circumferentially extending slots in the circular wall of passage 15 but as a practical matter, and in order to provide a circumferentially uniform air flow around the base of the tower each passage 15 merges along its intermediate portion 21 from a circular cross-section into a rectangular cross-section having horizontal upper and lower wall 22, and 23 and vertical side walls 24, the terminal ends of the side wall 24 of adjacent passages having common vertical margins 25 which define with the terminal margins of upper and lower walls 22 and 23 the outlet end 26 of each passage.
In view of the complexity involved in attempting to provide additional air openings extending circumferentially around the circular portion of each of the passages 15 it may be desirable to maximize the width to height ratio of the rectangular outlets 26 and to provide one or more transverse vertically oriented slotted openings 27 only in the upper and lower walls 22 and 23 in the rectangular portion of each passage downstream from the windmill 17.
The effectiveness of providing the additional air inlets 27 is illustrated in FIG. 5 wherein the envelope curve 28 defined by the horizontal arrows at the left indicate relative unit air velocities existing in a vertically direction upwardly from the bottom wall 23 in a passage 15 upstream from a slot 27, the envelope curve 29 denotes relative unit air velocities in the air entering the slot and the combined curve 30 shows the extent to which air velocities across the height of the passage may become equilized by the addition of air. In a sense it can be said that the added air acts as a lubricant at the interface between the upper and lower boundaries of the main body of flowing air and its confining walls.
From an observation of FIG. 2 it can be seen that, it there are nine air inlet passages disposed about the base of the tower 10, regardless of the direction from which the wind is blowing, there will always be at least three, and possibly as many as four, of the inlets 16 which are positioned to capture portions of the blowing air and to rotate the windmills 12 positioned directly downstream from those inlets to generate electricity in varying amounts by the devices 18 connected to them. However, in operation, the incoming air flow enters the tower from all sides, regardless of the ambient wind direction. This is because the density difference between the warm air inside the tower and the cooler air outside the tower results in a pressure difference which causes the air to enter from all sides. Thus all of the wind turbines can generate power at the same time.
As the currents of air in each passage moves downstream the expanding cross-sections of the passages alows the air to expand, thus reducing back pressure and increasing the efficiency of the windmills. Efficiency is further improved by the provision of the additional air inlets 27 which allows air to be drawn in, not only as a result of external wind pressure but due to the suction created by the internal flow of air whereby boundary layer effects are controlled and a more nearly equalized pressure across the entire cross-section of the passages is obtained. To accommodate the increased volume of air due to expansion and the addition of outside air it is calculated that the cross-sectional area of each of the outlets 26 should be approximately three times that of areas of the inlets 16 in order to satisfactorily reduce back pressure of the wind turbine devices 12.
By arranging each of the air passages 12 to direct air in symmetrical helical paths, the currents of air leaving the respective outlets 26 join together at the base of the tower 10 to generate a single helical upwardly directed flow of air within the tower, as indicated by the arrows in FIG. 1. Studies have further shown that the horizontal orientation of the air passages should be such that the body of air entering from each of the passages should be directed at an angle α no greater than 30° with respect to a radius of the tower, as can be seen in FIG. 2. If the air is directed into the tower by the passages at angles greater than 30° there will be increasing tendency for the air from each of the passages 15 to create its own individual vortical pattern which, of course, will oppose and conflict with those generated by the other passages rather than to blend in additively with the flow from the other passages to generate a swirling pattern encompassing the entire interior of the tower.
The benefit of this homogeneous vortical upward air flow pattern can be seen by a comparison between FIGS. 6 and 7 in which FIG. 6 illustrates the fact that when the flow of air in a tower 31 moves upwardly in an uncontrolled natural direction the plume 32 of air exiting from the top of the tower is blown to the right by a wind from the left as soon as the plume leaves the tower. On the other hand, in the tower 33 of FIG. 7 in which the air flows upwardly in the tower in a controlled vortical pattern it continues upwardly from the top of the tower for a certain distance, indicated by arrow 34, undisturbed by the wind flowing from the left, before the plume 34 is dissipated by the wind. By analogy the forces of the upward drafts disclosed in FIGS. 6 and 7 resemble the behaviour of a ball fired from an antique cannon as compared to a projectile shot from a rifled gun. The result is to increase the effective height of tower 33 beyond its actual physical elevation and since the draft in the tower is a function of height the benefit of increased efficiency in the generation of power by wind turbine devices 12 is increased without the expense of additional construction costs.
Further in this connection it should be noted that other configurations of surfaces of revolution have been, and may be, employed in the construction of applicants' tower 10. These include cylindrical walls and walls defined by parabolic or hyperbolic curves in which the walls either continuously converge, or converge and diverge, in an upward direction but a preferred construction involves the use of a tower having an upwardly converging conical wall.
A proposed construction would consist of a tower in the form of a frustum of a cone having an overall height of 300 feet from the ground to the exit plane, with a base diameter of 140 feet and of 130 feet at the exit plane. Nine windmills with 24 foot diameter blades were placed around the tower base. Two percent of the available 28,000 lbm/sec air flow was reserved for boundary layer control (see FIG. 3). The windmill rotor air velocities were calculated to be 85 ft/sec and the air velocity at the entrance to the tower was 28.4 ft/sec. The passages were oriented with respect to the tower such that the entering air velocity components were: w i =5 ft/sec, v i =7.3 ft/sec, and u i =-27 ft/sec (minus sign denotes radial inflow). The augmented air windmill efficiency was conservatively taken as 1.186 or twice the theoretical efficiency of windmills which remove only kinetic energy from the air. It is possible that diffuser augmentation efficiencies of 2.7 to 4.0, depending on centerbody design, are possible.
The effluent water was sprayed into the tower at a level of 23 feet above the ground in droplet sizes of 0.05 inch. Larger drop sizes require that they be introduced at greater heights which are uneconomical for pumping costs, while smaller droplets tend to be carried upwardly with the air flow.
Calculations indicate that an exit plane axial velocity of approximately 40 ft/sec for the cone-shaped tower is obtained. For the maximum air flow of 28,000 lbm/sec, the 40 ft/sec axial axit velocity indicated an approximate viscous vortex core of 60 ft diameter. With no vortex, conservation of mass indicated if the entire exit plane area was available for flow the exit axial velocity would be 31.7 ft/sec. The difference in axial exit velocities for the vortex and non-vortex cases would suggest a 26% increase for the vortex case.
Having disclosed one form in which the invention may be practical it will be apparent that modifications and improvements may be made which would fall within the scope of the annexed claims. | A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passages to provide power as a by-product. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the construction of wells for the production of petroleum products and more specifically to the construction and completion of multilateral branches from a main well bore to enable the production of petroleum products from several subsurface zones. Even more specifically the present invention concerns methods and apparatus for connecting a lateral branch liner to a main well bore to achieve predictable and stable mechanical connectivity at the lateral junctions of branch well bores to the main well bore to counter the problems of formation instability at the branch junction which may cause partial or total obstruction of the lateral or main bore at the level of the lateral junction.
2. Description of the Related Art
In the field of multilateral well construction and production operations one of the most valuable attributes of a junction is the connectivity of lateral branches with the main bore. Partial or total loss of connectivity of the main bore with a lateral branch may cause fluid production loss. Major connectivity problems may also result in partial or total obstruction of the main or lateral bore at the level of the lateral junction. The consequences of such problems are a substantial penalty to the operator of a well in the form of lost opportunity, increased operating cost, or lost production. The root cause of not being able to achieve or maintain connectivity at a lateral junction can be divided into two general areas: mechanical integrity problems and production of solids from the formations surrounding the junction. Mechanical integrity problems are usually a combination of design factors limiting the strength of, and mechanical forces applied by the surrounding formations onto, the connecting equipment. Production of solids from surrounding formations occurs when the junction technique does not achieve a consistent connectivity by means of mechanical liner tie-back solutions. This can be the case when a liner is connected to the parent well bore by means of cement or any similar joining technique which does not withstand tensile or shear forces that may be induced by formation pressures or subsidence or any other formation movement at the level of the lateral junction.
One form of prior art is the use of a mechanical connection embedded with a casing section which has one or a plurality of pre-fabricated windows. Although such solution provides a possible connection of the lateral liner to the parent well bore, it requires a special vessel to be installed in line with the casing string at a specific depth and, more importantly, with a correct orientation with respect to earth gravity in order to place the pre-fabricated window in the direction of the projected lateral branch. This method requires very thorough well planning and delicate control of parent casing running procedures. Another drawback of this method is that connective template and retaining features are run with the parent casing and must therefore remain protected from any mechanical abuse while drilling in the parent section or drilling the lateral branch. Such method and apparatus generally requires other additional equipment to complete the well with lateral re-entry capability. Such device may be or similar to equipment for through-tubing re-entry by means of a secondary template. As a result a junction fully completed with such method will generally offer limited diameter to access the lower section of a parent well.
Another commercially available form of lateral connectivity does not require pre-orientation of the parent casing since it is implemented by milling lateral windows in installed well casing. The lateral liner is retained into the parent well bore and cemented into place. A window is then milled into the lateral liner in order to re-establish communication between the lower section of the main bore and the lateral and upper section of the main bore. However, most mechanical integrity of the lateral connection involves cement or similar filling material placed in the space surrounding the junction. As explained above, the cement lacks sufficient structural integrity, especially when shale in the formation shifts from time to time as the formation changes consistency due to production of fluid therefrom or due to production fluid from a lower or different formation, so that the cement becomes fractured and impairs the connectivity of the branch junction.
Another form of lateral connectivity is accomplished by conveying a liner into the lateral branch after milling a window in the parent casing and after lateral drilling. The liner is cemented into place while the liner is held in the parent well with a liner hanger. After the cement has set, cement excess and the liner top is “washed-over” with adequate milling and fishing tools. A deflection tool left in the parent well is then retrieved and this should normally leave a full bore in parent well. Completion equipment is then set in the junction, assuming an indexing packer is left below the junction. The major drawbacks of such method are similar to those described above, since the mechanical integrity of the junction involves cement or similar filling material which has been placed while setting the lateral liner.
Another form of lateral connectivity takes the form of a prefabricated outlet which fits mechanically within a special vessel that is connected in line with the parent casing. The special vessel supports a selective positioning profile and an orienting profile. The outlet is conveyed with the parent casing in retracted position and deployed in the main bore by action of an expansion tool which extends the outlet around a hinge placed on top of the outlet. The outlet and vessel are interlocked and sealed after the outlet is fully extended. A liner can be set, and retained in the lateral outlet bore by means of a liner-hanger-packer device. Such method requires a very complex deployment process and more importantly requires the special vessel to be placed and oriented in a precisely predetermined position while running the parent casing, and requires the outlet to be extended before cementing. Also the fact that a lateral outlet is pre-installed in the junction restricts the size of lateral drilling with conventional methods.
SUMMARY OF THE INVENTION
It is a principal feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore with predictable mechanical stability in a manner that eliminates or significantly minimizes the possibility of losing connectivity at the level of the lateral junction with the main well bore;
It is a principal feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore in a manner providing the capability for selectively re-entering the lateral branch in a controlled way utilizing a locking profile which is a component of the liner connector/template;
It is a principal feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore which effectively prevents formation solids from entering into the production bore;
It is a principal feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore wherein a pre-fabricated junction is provided, which is composed of two mating parts, template and connector, which may be assembled and tested at the surface, disassembled, and then re-assembled downhole using conventional running tools;
It is another feature of the present invention to provide a novel method and apparatus for connecting a lateral branch to a main well bore wherein some guiding features are also interlocking features which prevent radial movement of the connector in or out of the junction template under the effect of formation pressure or fluid pressure;
It is another feature of the present invention to provide a novel method and apparatus for connecting a lateral branch to a main well bore wherein guiding features allow full engagement and final placement of the connector in the template by action of bending forces to elastically or plastically shape the connector in situ and thus complete the lateral connection;
It is another feature of the present invention to provide a novel method and apparatus for connecting a lateral branch to a main well bore wherein guiding features provided on the two connecting components, template and connector, allow accurate placement and orientation of the connector with respect to the template so electrical connection can be established in order to transmit signals and or power in the main bore or from the main bore to the lateral branch;
It is another feature of the present invention to provide a novel method and apparatus for connecting a lateral branch to a main well bore wherein a pre-fabricated junction composed of the template and the connector can be retrieved out of the well using conventional retrieving tools and then reinstalled downhole;
It is a feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore which permits running and setting of the casing for the main well bore without necessitating controlled casing orientation and yet permitting one or more lateral branches to be subsequently drilled at a controlled inclination and along a predetermined azimuth from the main well bore via the use of an indexing coupling or other indexing device that is present within the casing of the main well bore;
It is another feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore, which prevents fine solids from the surrounding formation from entering the junction;
It is another feature of the present invention to provide a novel method and apparatus for connecting a lateral branch liner to a main well bore wherein branch bore controlling apparatus, junction template and connector are designed for conveyance to desired well depth by means of running and setting tools that may be conveyed within the well by jointed pipe or coiled tubing;
It is an even further feature of the present invention to provide a novel method and apparatus for use in existing wells for connecting a lateral branch liner to a main well bore even in circumstances where the casing of the existing well is not provided with an indexing coupling or other indexing device;
It is also a feature of the present invention to provide a novel method and apparatus for connecting a lateral branch bore to a main well bore while providing for electrical and/or hydraulic connection between main and lateral well systems to thereby enable controlled production of fluid from a plurality of subsurface production zones.
Briefly, the present invention embodies a method and apparatus for achieving efficient, predictable and stable mechanical connectivity of a lateral branch junction with a main well bore and thereby eliminating or significantly reducing the potential for losing connectivity at the level of a lateral junction of a well. This lateral junction connectivity is implemented after the lateral construction phase of the well has been completed and does not require dedicated positioning and orienting features in the parent casing string. This method and apparatus may be implemented in a plurality of locations in a main well bore. According to the present invention, junction connectivity apparatus is capable of being assembled and tested at the surface to verify its mechanical fit before installation in a well. The two basic components of the connectivity assembly, a retrievable lateral branch template and a retrievable lateral branch connector are separated after assembly and testing at the surface and are then sequentially installed into the well and assembled downhole to thus define a pre-tested branch junction connectivity assembly that significantly simplifies the installation and operating procedures of the well.
According to the general method of the present invention a mechanical junction template is located in the casing of the main bore at the level of a lateral opening, commonly called a “window”, that has been formed in the parent casing prior to installing the connectivity assembly. Typically, a lateral window is milled in an installed and cemented casing before drilling a lateral branch, or a lateral window may have been pre-fabricated on a special casing joint before placing the casing in the main well bore. The casing may be provided with an indexing sub having a specific internal positioning profile and an orientation slot so that positioning and orientation of the lateral branch template may be easily established. Alternatively, indexing means, such as packer positioned indexing apparatus, may be installed within casing that is not provided with an indexing coupling. A lateral branch template is lowered in the main well casing and secured in registry with the casing window and lateral junction by means of equipment described hereafter. The template features a lateral opening which faces the casing window to enable a lateral branch liner to be run from the main bore and guided laterally through the casing window and into the lateral branch. A suitable lateral branch connector is lowered through the well casing and into the template and fits into guiding and interlocking mating features that are provided on the template. The mechanical fit of the connector with the template is intended to secure the lateral branch connector in a precisely defined position and to maximize the mechanical integrity of its connection with the lateral branch liner of the branch bore. The mechanical fit of the connector with the template is sufficiently tight to exclude ingress of solids from the formation to the flow path that is defined by the interconnected components, though a positive hydraulic seal may be employed if desired.
In the event it is desired to provide a plurality of lateral branches from the main well bore at any particular location, a plurality of lateral branch templates and connectors may be employed in stacked relation with the forward most template indexed with respect to the main well casing and with successive templates indexed with each other or individually indexed to the main well casing.
The method of the present invention also includes the capability to selectively re-enter a lateral branch and to also prevent well bore solids from entering the production fluid at the level of the junction. Both lateral branch template and lateral branch connector are prefabricated and installed into the well by means of running and setting tools. These running and setting tools can be conveyed with jointed pipe, or coiled tubing. Electrical or hydraulic power may be used in combination with push, pull, or torque actions to deploy the equipment and record feedback while installing the equipment downhole. The equipment can be deployed in wells constructed with any inclination and orientation. The method and apparatus for lateral connection can accommodate low or high dogleg severity at kick-off. The method and apparatus may be applied in the same way to water wells, gas wells, oil wells, injection wells, or wells where injection and oil production alternate, in wells having a casing including an indexing sub and wells having a casing without an indexing sub. In the case of wells that have no indexing casing coupling pre-installed in the vicinity of the junction, an indexing device, such as one or more indexing packers or any other means providing orientation and position references, may be placed and secured in the main casing prior to installation of the lateral branch template. The template may also be installed in wells that have no indexing device placed in the main bore in the vicinity of the junction by controlling position and orientation of the template with respect to the main casing by means of various orientation and positioning systems such as an inclination or gyroscopic survey tool placed in the running tool string, a measuring while drilling (MWD) system, or a gamma ray positioning system. Thus it is not necessary according to the scope of the present invention to provide a mechanical indexing system in the well casing. When a mechanical indexing device is not present within the main well casing, a packer connected to the bottom of the template can be set to secure the template in the junction.
The method and apparatus also include the capability to perform main and branch well production control tasks, or to carry equipment that participates in production monitoring or production control by means of suitable information processing devices and production flow controllers such as remotely controlled valves, production fluid parameter sensors or other similar equipment.
The method and apparatus also include the capability to transmit electrical or hydraulic power between the upper section of the main bore and the lower section of the main bore or between the lateral branch and the main bore. This feature is achieved by suitable electrical and/or hydraulic connections that are installed on the upper and the lower ends of the template, or between the lateral branch template and the lateral branch connector.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the preferred embodiment thereof which is illustrated in the appended drawings.
It is to be noted however, that the appended drawings illustrate only a typical embodiment of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the Drawings:
FIG. 1 is a sectional view illustrating part of a casing lined and cemented main well bore in an earth formation, showing the initial part of a branch bore drilled therefrom through a milled casing window and further showing the placement of a lateral connection assembly within the main well bore in preparation for lateral branch activities;
FIG. 2 is a sectional view taken along line 2 — 2 of FIG. 1;
FIG. 3 is a sectional view taken along line 3 — 3 of FIG. 1;
FIG. 4 is a sectional view taken along line 4 — 4 of FIG. 1;
FIG. 5 is a sectional view taken along line 5 — 5 of FIG. 1;
FIG. 6 is a sectional view taken along line 6 — 6 of FIG. 1;
FIG. 7 is an isometric illustration in partial section showing a lateral branch template constructed according to the principles of the present invention and having the upper portion thereof cut away to show positioning of a diverter member within the upper portion of the template;
FIG. 8 is an isometric illustration similar to that of FIG. 7 and showing a liner connector member and isolation packers in assembly with the lateral branch template;
FIG. 9 is an isometric illustration showing the liner connector member of FIG. 8;
FIG. 10 is an isometric illustration showing the diverter member that is located within the lateral branch template as shown in FIGS. 7 and 8;
FIG. 11 is a fragmentary sectional view showing part of a main well casing cemented within a main well bore and further showing part of a lateral branch template located within the main well casing and oriented by an indexing coupling with a branch liner diverted through a casing window into a lateral branch bore with the lower end thereof received in sealed relation within a cemented lateral branch casing;
FIG. 12 is a fragmentary sectional view similar to that of FIG. 11 showing monitoring and/or control apparatus latched within the lateral branch tube of the lateral branch connector for sensing and/or controlling production of the lateral branch well section;
FIG. 13A is a longitudinal sectional view of the upper section of a lateral branch template constructed in accordance with the principles of the present invention and having a lateral branch connector in assembly therewith;
FIG. 13B is a longitudinal sectional view of the lower section of the lateral branch template and connector assembly of FIG. 13A;
FIG. 14A is an isometric illustration showing the upper section of the lateral branch template of FIGS. 13A and 13B;
FIG. 14B is an isometric illustration showing the lower section of the lateral branch template of FIGS. 13A and 13B;
FIG. 15A is an isometric illustration showing the inner side of the upper section of a lateral branch connector constructed in accordance with the principles of the present invention and being a part of the template/connector assembly of FIGS. 13A and 13B;
FIG. 15B is an isometric illustration showing the inner side of the lower section of the lateral branch connector of FIG. 15A as also shown in FIGS. 13A and 13B;
FIG. 15C is an isometric illustration showing the outer side of the lower section of the lateral branch connector of FIGS. 15A and 15B and particularly showing the flexing intermediate section thereof;
FIG. 16 is a fragmentary elevational view of the well casing of a main well bore showing a casing window that is milled to additionally define a positioning and orienting geometry for engagement by the orienting key of the lateral branch template or other apparatus; and
FIG. 17 is a fragmentary sectional view of a section of main well casing showing a casing window and a positioning and orienting slot located within the casing, and showing in broken line a positioning and orienting slot out of rotational phase with the casing window.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and first to FIGS. 1 — 8 , FIG. 1 illustrates the placement of a lateral branch junction connection assembly shown generally at 10 within the main well casing 12 of a main well bore 22 that is drilled within an earth formation 16 . The lateral branch junction connection assembly 10 is defined by two basic components, a lateral branch template and a lateral branch connector which, when in assembly, cooperatively define a lateral branch junction connection assembly having sufficient structural integrity to withstand the forces of formation shifting. The assembled lateral branch junction also has the capability of isolating the production flow passages of both the main and branch bores from ingress of formation solids. After the main well bore and one or more lateral branches have been constructed, a lateral branch template 18 is set at a desired location within the main well casing 12 which will have been cemented by cement 20 within main well bore 22 . A window 24 will have been formed within the main well casing 12 for each lateral branch, either having been milled prior to running and cementing of the main well casing 12 within the main well bore 22 or having been milled downhole after the main well casing 12 has been run and cemented. A lateral branch bore 26 is drilled by a branch drilling tool that is diverted from the main well bore 22 through the window 24 and outwardly into the earth formation 16 surrounding the main well bore. The lateral branch bore 26 is drilled along an inclination that is established by a whipstock or other suitable drill orientation control. The lateral branch bore 26 is also drilled along a predetermined azimuth that is established by the relation of the drill bit orientation control with an indexing device that is connected in the casing string or set within the casing string.
As shown in FIGS. 1-6 a lateral branch connector 28 is attached to a lateral branch liner 30 which connects the lateral branch bore 26 to the main well bore 22 . It is important to note that the lateral branch connector 28 establishes fluid connectivity with both the main well bore 22 and the lateral branch bore 26 . FIGS. 2-6 are transverse sectional views taken along respective section lines 2 — 2 through 6 — 6 of FIG. 1 and showing the structural interrelation of the various components of the lateral branch template 18 and the lateral branch connector 28 . As shown in FIG. 1 and also in FIG. 11, a generally defined ramp 32 cut at a shallow angle in the lateral branch template 18 serves to guide the lateral branch connector 28 toward the casing window 24 while it slides downwardly along the lateral branch template 18 . Optional seals 34 , which may be carried within optional seal grooves 36 on the lateral branch connector 28 , as shown in FIGS. 1, 4 , 5 and 6 establish sealing between the lateral branch template 18 and the lateral branch connector 28 to ensure hydraulic isolation of the main and lateral branch bores from the environment externally thereof. A main production bore 38 is defined when the lateral branch connector 28 is fully engaged with the guiding and interlocking features of the lateral branch template 18 which will be described in detail below. Interengaging retaining components (not represented in FIG. 1) located in the lateral branch template 18 and the lateral branch connector 28 prevent the lateral branch connector 28 from disengaging from its interlocking and sealed position with respect to the lateral branch template 18 . This feature will be described in detail below in connection with FIGS. 4 through 6, 14 A and 14 B, and 15 A and 15 B.
FIGS. 2 and 3 illustrate the lateral branch template 18 and the lateral branch connector 28 by means of transverse sectional views along the section lines depicted in FIG. 1 . The transverse sectional views of FIGS. 2-6 show how the main production bore 38 in the sectional view of FIG. 2 , separates into two isolated production bores in the transverse sectional view of FIG. 6 . The main well casing 12 is cemented within the main well bore 22 by cement 20 which is pumped into the annulus between the well casing and the well bore in the usual fashion and is allowed to harden so that the main well casing 12 is substantially integral or mechanically interlocked with respect to the surrounding formation. A lateral window 24 is shown in FIGS. 3 and 4 which leads from the main well bore 22 to the lateral branch bore 26 . The lateral branch connector 28 is guided and interlocked into the lateral branch template 18 by means of tongue and groove type interlocking features 44 shown particularly in FIGS. 4, 5 and 6 and shown in greater detail in FIGS. 14B, 15 B and 15 C. Optional seals 34 for hydraulic isolation of the main and lateral branch bores from the environment externally thereof may be included between the lateral branch template 18 and the lateral branch connector 28 if desired. The mechanical interrelation of the lateral branch template 18 and the lateral branch connector 28 is, however, sufficient to isolate the production bores of both the lateral branch bore and main well bore from intrusion by solids from the formation.
FIGS. 7-10 collectively illustrate the lateral branch junction connection assembly 10 by means of isometric illustrations having parts thereof broken away and shown in section. The lateral branch template 18 supports positioning keys 46 and an orienting key 48 which mate respectively with positioning and orienting profiles of positioning and orientation means such as the indexing coupling 50 set into the main well casing 12 as shown in FIG. 11 . If the lateral branch construction procedure is being accomplished in a well which is not provided with an indexing coupling or other indexing means within its main well casing, indexing means can be oriented and set at any desired location within the existing well casing, thus permitting the lateral branch template 18 to be accurately positioned with respect to a casing window that is milled in the casing and with respect to a lateral branch bore that is drilled from the casing window. An adjustment adapter mechanism shown at 52 in FIGS. 7 and 8 allows adjustment for depth and orientation between the lower section of the lateral branch template 18 and positioning keys 46 and orienting key 48 , and the upper section of the lateral branch template 18 supporting lateral branch connector 28 . For directing various tools and equipment into a lateral branch bore from the main well bore a diverter member 54 including selective orienting keys 56 fits into the main production bore of the lateral branch template 18 and defines a tapered diverter surface 58 that is oriented to divert or deflect a tool being run through the main production bore 38 laterally through the casing window 24 and into the lateral branch bore 26 . The lower diverter body structure 57 is rotationally adjustable relative to the tapered diverter surface 58 to thus permit selective orientation of the tool being diverted along a selective azimuth. The selective orienting keys 56 of the diverter 54 will be seated within specific key slots of the lateral branch template 18 while the upper portion 59 of the diverter 54 will be rotationally adjusted relative thereto for selectively orienting the tapered diverter surface 58 . Isolating packers 60 and 62 are interconnected with the lateral branch template 18 and are positioned respectively above and below the casing window 24 and serve to isolate the template annular space respectively above and below the casing window.
According to the preferred method for connecting a lateral branch liner to a main well casing the main or parent well casing is located within the main well bore and supports one or more indexing devices such as an indexing coupling 50 or any indexing sub that can be permanently installed in the parent casing below the junction. Alternatively, locating and indexing means may be set at any desired location within a main well casing, such as by one or more packers, for example. Also, positioning and orientation of the lateral branch template may be established by MWD systems, gamma ray logging systems, movable packers and the like. Indexing features include positive locating systems to position accurately the template in depth and orientation with respect to the lateral window. The main well casing has one or a plurality of lateral windows referenced to the indexing device or devices to thus permit one or more lateral branch bores to be constructed from the main well bore and oriented according to the desired azimuth and inclination for intersecting one or more subsurface zones of interest.
The lateral branch window(s) is typically milled in the casing after main well casing has been set and cemented. In this case, the main well casing does not need to be oriented before cementing. Alternatively to the above, the lateral window can be pre-fabricated into a special vessel or coupling that is installed in line in the main well casing string. In this case, the main well casing requires orientation before cementing in order to conform the orientation of the lateral branch with the well construction plan.
Whether the casing window is pre-fabricated within the casing or formed within the casing after the casing has been installed and cemented, as shown in FIGS. 16 and 17, the casing may be provided with one or more positioning and orienting slots which may be formed to define the geometry of the casing window or may be located within the casing in the immediate vicinity of the casing window and may be in rotational phase or out of rotational phase with the casing window as desired. As shown in FIG. 16, the main well casing 12 defines a casing window 24 essentially as shown in FIGS. 1-4. In this case the lower end of the casing window has been formed, such as by milling, to define side surfaces 25 and 27 which define a positioning and orienting slot 29 . The bottom curved edge 31 of the slot 29 provides for positioning while the generally parallel side surfaces 25 and 27 provide for orientation of the lateral branch template 18 or any other tool that is positioned and oriented within the casing. FIG. 17 shows a main well casing 12 having a casing window 24 . Below the casing window the casing has been formed, such as by milling, to define a positioning and orienting slot 33 having generally parallel side edges 35 and 37 and upper and lower ends 39 and 41 . The positioning and orienting slot 33 , like the positioning and orienting slot 29 , is adapted to receive the orienting key 48 of the lateral branch template 18 or any other tool that is intended to be positioned and oriented within the casing. As shown in FIG. 17, the positioning and orienting slot 33 , shown in full line, is in rotational phase with the casing window 24 . Alternatively, as shown in broken line at 33 ′, the positioning and orienting slot may be located out of rotational phase with the casing window 24 .
The lateral branch template 18 is properly located and secured into the main well bore 22 by fitting into an indexing device to position accurately the template in depth and orientation with respect to the window 24 in the main well casing 12 . The lateral branch template 18 has adjustment components that are integrated into the lateral branch template 18 and which allow for adjusting the position and orientation of the lateral branch template with respect to the lateral casing window. The main production bore 38 allows fluid and production equipment to pass through the lateral branch template 18 with minimal restriction so access in branches located below the junction is still allowed for completion or intervention work after the lateral branch template 18 has been set. The lateral opening 42 in the lateral branch template 18 provides space for passing a lateral branch liner 30 and for locating the lateral branch connector 28 which fits in it with tight tolerances taking advantage of controlled prefabricated geometries.
The lateral branch template 18 incorporates a landing profile and a latching mechanism which allows supporting and retaining the lateral branch connector 28 so it is positively connected to the main production bore 38 . The lateral branch template 18 also incorporates guiding and interlocking features which cause diverting and guiding movement of the lateral branch connector 28 through the lateral opening and positioning the lateral branch connector 28 to provide support against forces that may be induced by shifting of the surrounding formation or by the fluid pressure of produced fluid in the junction.
The lateral branch template 18 also provides a selective landing profile and associated orienting profile in which can fit a diverter 54 used to direct equipment from uphole through the casing window 24 and toward the lateral branch bore 26 . The upper and lower ends of the lateral branch template 18 are treated so production tubing can be connected without diameter restriction by means of conventional production tubing connections. The lateral branch template 18 provides a polished bore receptacle for eventual tie back at its upper portion and is provided with a threaded connection at its lower portion. As an option, the annular space between lateral branch template 18 and main well casing 12 is isolated both above and below the lateral casing window 24 by means of isolating packers 60 and 62 to provide the well ultimately and selectively with isolation of either the lower section of the main production bore 38 or the lateral branch bore 26 .
As an option, the upper and/or lower ends of the lateral branch template 18 may be equipped with electrical connectors and/or hydraulic ports so electrical and/or hydraulic fluid connections can be achieved downhole in order to carry power and/or signal lines through the template and along the main production bore 38 . Electrical connection can take the form of a mechanical contact connection, inductive connections, or electromagnetic connections. The end connection may be directed to equipment temporarily or permanently installed on the template. As shown in FIGS. 11 and 12, the lateral branch connector 28 is shown provided with power connector means, shown generally at 64 , which comprise an electrical and/or hydraulic connector. A tubing encapsulated cable 66 extends substantially the length of the lateral branch connector 28 and, in the case of an electrical connector, is provided with parent bore and branch bore inductive couplings 68 and 70 . The parent bore inductive coupling 68 is located within a polished bore receptacle 72 having an upper polished bore section 74 which is typically engaged by seal means 71 located at the lower end of a section of production tubing 75 as shown in FIG. 12 . It should be borne in mind that the seal means 71 may be located in well components other than the production tubing 75 if desired. For example, the seal means 71 may be supported by a connector device being a component of running equipment for installation and removal of the lateral branch connector 28 or for running and retrieving the lateral branch template 18 or other lateral branch equipment. The parent bore inductive coupling 68 will typically derive its electrical energy from a power supply and control conductor 76 that extends along the exterior of the production tubing 75 to the surface where it is connected with an electrical power supply and connected with appropriate control conductors. When the upper junction production connection 73 is properly seated within bore receptacle 72 its inductive coupling 77 will be in induction registry with the parent bore inductive coupling 68 , thereby completing the power supply connection to the lateral branch connector 28 . The power supply and control conductor 76 may also incorporate hydraulic supply and control conductors for the purpose of electrically or hydraulically controlling and operating downhole equipment of the main or branch bores of the well.
As further shown in FIGS. 11 and 12, lateral branch connector 28 defines an internal latching profile 80 which receives the external latching elements 82 of a lateral production monitoring and/or flow control module 84 . This module can take any suitable form, such as an electrically operated flow control valve, an electrically adjustable flow controlling choke device, a pressure or flow monitoring device, a monitoring device for monitoring various branch well fluid parameters, or a combination of the above. Lateral branch connector 28 is connected by a threaded connection 86 to a lateral connector tube 88 having an end portion 90 that is received within a lateral branch connector receptacle 92 of the lateral branch liner 30 and sealed therein by sealing means 94 . The lateral production monitoring and/or flow control module 84 is provided at its upper end with a module setting and retrieving feature 96 with permits running and retrieving of the module by means of conventional running tools. The module 84 is provided with an inductive coupling 98 which is in inductive registry with the branch bore inductive coupling 70 when the module 84 is properly seated and latched by the latching elements 82 .
As shown in the isometric assembly illustrations of FIGS. 13A and 13B the lateral branch connector 28 is shown in interlocking assembly with the lateral branch template 18 . From these assembly illustrations it will be seen that the lateral bore axis 100 of the lateral branch connector 28 is disposed in angular relation with the main bore axis 102 of the lateral branch template 18 .
The upper section of the lateral branch template 18 is shown in FIG. 14A wherein the lateral opening 42 is defined by generally parallel side surfaces 104 and 106 which restrict lateral movement of the lateral branch connector 28 relative to the lateral branch template 18 and are joined at the upper end by a curved end surface 108 . As the lateral branch connector 28 is moved forwardly the angulated ramp surfaces of the lateral branch template 18 guide the lower end portion of the lateral branch connector 28 through the lateral opening 42 . The lower section of the lateral branch template 18 , also referred to as the interlocking section, is shown in FIG. 14 B and also defines the inclined ramp that is generally indicated at 32 in FIGS. 1 and 11. The interlocking section defines other interlocking features that cooperate to mechanically interlock the lateral branch template 18 and the lateral branch connector 28 in properly positioned assembly to form a lateral branch connection that has sufficient structural integrity to withstand the external mechanical force that might be caused by shifting of the surrounding earth formation.
The efficient connection of the interlocking section binds the lateral branch connector 28 into sufficiently tight assembly with the lateral branch template 18 to substantially prevent solids from entering the production stream from the lateral branch and permits branch connector movement that establishes efficient sealing with the lateral branch liner 30 of the lateral branch bore. In the interlocking section the lateral branch template 18 defines opposed orientation grooves 110 , one of the orientation grooves being shown in the isometric illustration of FIG. 14B, which define at least one angulated guide surface for guiding the lower end of the interlocking section of the lateral branch connector 28 into interlocking relation with the lateral branch template 18 . Immediately below the orientation grooves 110 the interlocking section of the lateral branch template 18 defines rear tongue and groove interlocks 112 . Below the rear tongue and groove interlocks 112 the interlocking section defines side exit guiding ramp surfaces 114 which are disposed in angular relation with the parent or main well bore axis 102 shown in FIG. 13 B. These side exit guiding ramp surfaces 114 cause lateral movement of the lower end of the lateral branch connector 28 as the connector is moved downwardly relative to the lateral branch template 18 . Front tongue and groove interlocks 115 are provided below the side exit guiding ramp surfaces 114 and serve cooperatively with the rear tongue and groove interlocks 112 to lock the lateral branch connector 28 in releasable assembly with the lateral branch template 18 . The inclined guiding ramp surfaces 114 also cause the lateral branch connector 28 to be drawn into sufficiently tight engagement with the lateral branch connector 18 to define a connectivity assembly that establishes a production flow path and substantially excludes ingress of solids from the formation into the production flow path. The tightly engaged relation of the lateral branch connector 28 with the lateral branch template 18 also defines a junction connectivity structure of sufficient structural integrity to withstand the forces of formation shifting and maintain connectivity of the lateral branch junction with the main well bore. If it is considered desirable to provide additional structure between the lateral connectivity junction and the formation, such as to enhance the structural integrity of the lateral connectivity junction and/or to enhance the fluid sealing and solids excluding capability of the lateral connectivity junction, a liquid composition such as cement or polymer may be used to neutralize the surrounding environment about the connectivity junction by filling the space between the lateral connectivity junction and the formation.
At the lower end of the interlocking section the lateral branch template 18 defines a positive lower connector stop 116 which is engaged by a connector stop member to prevent further downward movement of the lateral branch connector 28 . In this regard it should be borne in mind that proper lateral connectivity of the lateral branch connector 28 with the lateral branch liner 30 may be made without downward movement of the lateral branch connector being stopped by the connector stop 116 .
Referring now to FIGS. 15A, 15 B and 15 C, the lateral branch connector 28 is shown in detail, with the upper section thereof being shown in FIG. 15 A. The isometric illustrations of FIGS. 15A and 15B are oriented for viewing the inner side of the lateral branch connector 28 . In contrast, the isometric illustration of FIG. 15C is arranged to show the outer side of the lateral branch connector 28 and particularly the flexing section 134 which permits elastic or plastic deformation of the lateral branch connector 28 to permit its bending to direct it from coaxial relation with the lateral branch template 18 to the angulated, laterally diverted relation shown in FIGS. 13A and 13B as the lateral branch connector 28 is moved forwardly into seated and interlocked relation within the lateral branch template 18 . The lateral branch connector 28 defines an upper tubular section 118 having a side opening 120 that is defined by a cut-away section having opposed side edges 122 and 124 . As shown in FIG. 15B, the side edges 122 and 124 merge with rear locking features 126 and 128 that are oriented for interlocking relation with the rear tongue and groove interlocks 112 of the lateral branch template 18 . The side opening 120 and the interlocking section of the lateral branch connector 28 is further defined by front locking features 130 and 132 which are adapted for interlocking relation with the front tongue and groove interlocks 115 . As the lateral branch connector 28 is moved downwardly within the lateral branch template 18 the front ( 130 , 132 ) and rear ( 126 , 128 ) locking features thereof will be moved into interlocking relation with the front 115 and rear 112 tongue and groove interlocks. Since the tongue and groove interlocks are inclined with respect to the longitudinal axis of the lateral branch template 18 to thus form guide ramps, the lateral branch connector 28 will be forced to follow the inclined path of the guide ramp interlocking geometry as the lateral branch connector is moved forwardly within the lateral branch template 18 . As this activity occurs, the lateral branch connector 28 will be elastically and/or plastically deformed in that its forward end will be diverted from a co-axial relation with the lateral branch template 18 and main well casing and thus will be caused to follow the inclined path and move through the lateral opening of the template 18 , through the casing window 24 and into the lateral branch bore 26 . As shown in FIG. 15C the lateral branch connector 28 defines a flexing section 134 which is shown in FIG. 15 C and is developed by cutting away an exterior section of the lateral branch connector 28 located opposite the side opening 120 . Thus, as bending force is applied to the lateral branch connector 28 by the ramping action of the front and rear tongue and groove interlocks, the lateral branch connector 28 will be deformed or flexed predominantly in the flexing section 134 to permit its front end to move through the casing window 24 and into the lateral branch bore 26 .
When it is desired to ensure that the lateral branch connector 28 is in a substantially relaxed condition after its installation has been completed, the connector is pre-bent or pre-formed to the typically curved configuration that it will have. In this case, it may be physically straightened as necessary during its transit through the main well bore to permit its movement through the main well casing. Then, when the lateral branch connector 28 is diverted through the casing window 24 and into the lateral branch bore 26 by the lateral branch template 18 , it will return to its relaxed pre-bent or pre-curved condition. This feature may be especially important to minimize the potential for stress corrosion of the metal when the formation fluid being produced has elevated hydrogen sulfide content, such as when the production fluid is sour crude oil or sour natural gas.
As explained above, it is not necessary for the lateral branch connector 28 to move downwardly to its fill extent in order for lateral branch connectivity to be established. In the event, however, that the lateral branch connector 28 is moved downwardly to its full extent, a stop projection 136 will become shouldered against an arcuate stop shoulder that is defined by the lower connector stop 116 to prevent further forward movement of the lateral branch connector. If fluid connectivity has not been established at this point the lateral branch connector 28 must be withdrawn and its installation procedure repeated.
As an option, the lower section of the lateral branch template 18 located below the lateral connection and/or the upper section of the lateral branch template located above the lateral connection may include permanent measuring and production control equipment or may include mechanical features to support temporary measuring and/or production control equipment.
As an additional option, the lateral branch junction connection assembly comprising the lateral branch template and lateral branch connector may facilitate location therein of an active diverting device which, after the lateral branch junction has been completed, functions to divert any equipment intended for location within the lateral branch bore from the main well bore into the lateral branch bore. Installation and retrieval of the active diverting device is achieved by conventional running and retrieval equipment. It should be noted that a diverter device will not be installed in the lateral branch junction at the time the lateral branch junction is being installed. During installation of the lateral branch junction it is desirable that both the main well bore and the lateral branch bore be unobstructed so that fluid pressure returns may be employed to confirm proper assembly of the junction in the downhole environment. Only after proper installation of the junction connection assembly has been confirmed will a diverter be temporarily installed within the junction for diverting various tools and equipment, such as control valves, formation fluid parameter sensors, and logging tools, from the main well bore into a selected lateral branch bore.
The lateral branch connector is designed to establish an interlocking and substantially sealed connection with the lateral branch template to withstand loads that are induced thereto while running the liner or other equipment into the lateral branch, to withstand forces that may be caused by formation shifting, and to provide for exclusion of solids from the flow path that is defined by the junction. The interlocking assembly also provides for securing the lateral branch connector in fixed position and orientation with respect to the template. The lateral branch connector also supports a production tubular (the liner) connected to the lateral outlet. The lateral branch connector further define a lateral opening which permits fluid and production tools to pass through the junction and into the main production bore below the junction. At its upper portion the lateral branch connector has geometric features matching the template to allow retaining the lateral branch connector at a predetermined position within the main well bore. The lateral branch connector is also provided with an orienting, guiding and interlocking mechanism which allows for conveying the lateral branch connector into the lateral branch template, securing the lateral branch connector in the main template bore and to prepare the lateral branch connector for supporting forces that may be induced by shifting of the surrounding formation or by the pressure of produced fluid in the branch junction.
The lateral liner connects to the lateral branch connector at its upper end and connects to the upper portion of a lateral liner that has been installed prior to installing the connecting apparatus. Alternatively, the lateral liner may be set into the open well bore of the lateral branch along its entire length or along a portion of the lateral branch. The lateral liner also has any properties of liners that are installed in wells to isolate production or injection zones from other formations. The lateral liner may be or may not be cemented in the lateral bore depending upon the desires of the user. The mechanically interlocked relation with the lateral branch template and lateral branch connector obviates the need for cementing because, unlike conventional cemented junctions, the lateral liner, without cement, is structurally capable of withstanding mechanical or pressure induced forces that cause failure of conventional cemented lateral branch junctions.
As an alternative, the lateral liner may carry inside or outside its wall reservoir monitoring equipment which measures, processes, and transmits important data that identifies the evolution of reservoir characteristics while producing hydrocarbon products. This information may be transmitted to surface via suitable transmission means such as electric conductor cables, or electromagnetic or induction telemetry through or along the liner itself, provided adequate relays and connections are provided up to the lateral connection with the parent well.
In view of the foregoing it is evident that the present invention is one well adapted to attain all of the objects and features set forth above, together with other objects and features which are inherent in the apparatus disclosed herein.
As will be readily apparent to those skilled in the art, the present invention may be produced in other specific forms without departing from its spirit or essential characteristics. The present embodiment is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within the meaning and range of equivalence of the claims are therefore intended to be embraced therein. | A method and apparatus for establishing connectivity of lateral branch liners to main well casings to achieve predictable and stable mechanical connectivity at the lateral junction of branch well bores to the main well bore to counter the problems of formation instability at the junction. After construction of a well having one or more lateral branches, a retrievable lateral branch template is located in the casing of a main well bore in positioned and oriented registry with a casing window that opens to a lined lateral branch. A retrievable lateral branch connector is then installed in assembly with the template to cooperatively define a production flow path having maximized mechanical integrity and optimized production flow in both the lateral bore and the main bore. The lateral branch template and connector provide the capability to selectively re-enter a lateral branch and to also hydraulically isolate the formation surrounding the junction from fluid circulating in both the lateral branch and the main well bore. Both the lateral branch template and the lateral branch connector are prefabricated and installed into the well by means of running and setting tools. Electrical power or hydraulic pressure conductors incorporated in the template and connector assembly may be used to provide for production operation and control of main and branch well bore production after installation. The equipment can be deployed in wells constructed with any inclination and orientation and can accommodate low or high dogleg severity at kick-off. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional patent application Ser. No. 60/363,342, filed on Mar. 8, 2002,and entitled “Method Of Differentiating And Preserving Network Transmissions,” which is also incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to telecommunications in general, and, more particularly, to a technique for enabling the stations in a local area network to intelligently use their shared-communications channel.
BACKGROUND OF THE INVENTION
FIG. 1 depicts a schematic diagram of telecommunications system 100 in the prior art. Telecommunications system 100 transmits signals between communication stations 101 - 1 through 101 -P, wherein P is a positive integer, over shared-communications channel 102 . Because stations 101 - 1 through 101 -P share shared-communications channel 102 , they have to follow rules (or “protocols”) that govern, among other things, when and for how long they can each use the channel.
Many types of applications (e.g., e-mail, ftp, http, voice, video, etc.) send data across a local area network. The data for some of these applications—e-mail and web browsing for example—can be send with a lesser degree of urgency and, therefore, are called “latency-tolerant.” In contrast, the data for some other applications—particularly those that comprise a real-time component like video and audio—must traverse the network with a greater degree of urgency. These applications are called “latency-intolerant.”
IEEE 802.11 local area networks were initially designed for latency-tolerant applications and typically each of those applications share access to the shared-communications channel on an equal basis. This is usually acceptable for latency-tolerant applications. In contrast, this is often unacceptable for latency-intolerant applications because giving equal access to latency-tolerant and latency-intolerant applications might prevent the latency-intolerant application from getting its data in a timely manner.
If the latency-intolerant applications is deemed to be important, then a mechanism must be introduced into the network so that the latency-intolerant applications are given the amount of resources they need in a timely manner. Therefore, the need exists for a technique for enabling latency-tolerant and latency-intolerant applications to intelligently share access to the shared-communication channel.
SUMMARY OF THE INVENTION
The present invention enables latency-tolerant and latency-intolerant applications to intelligently share a shared-communications channel in a manner that seeks to satisfy the needs of all of the applications. In particular, the illustrative embodiment enables each application to be associated with a different class of service, wherein each class of service is associated with one or more quality-of-service parameters (e.g., minimum throughput, maximum latency, etc.).
The illustrative embodiment then effectively apportions access to the shared-communications channel by having the station transmit multiple frames at a single transmission opportunity (i.e., bursting) and by regulating the number of frames in each burst based on the class of service associated with the application.
Bursting is known in the prior art as a technique for increasing the bandwidth utilization of a shared-communications channel. In contrast, the illustrative embodiment utilizes bursting, and regulates the number of frames in each burst, to balance the needs of applications having different class of service parameters.
In the context of IEEE 802.11 local area networks, the illustrative embodiment is advantageous because it does not require a change to 802.11's coordination function (e.g., distributed coordination function, enhanced distributed coordination function, point coordination function, etc.). Furthermore, stations in accordance with the illustrative embodiment continue to gain access to the shared-communications channel on a statistically-equal basis, although higher-class-of-service applications are able to transmit more frames at each transmission opportunity than are lower-class-of service applications. The result is that applications having different class of service parameters are treated differently, yet while the statistical properties of the access coordination function remain unchanged.
An illustrative embodiment of the present invention comprises: queuing m frames in a queue; and transmitting a maximum of n frames of the m frames into a shared-communications channel when presented with an opportunity to transmit all m frames into the shared-communications channel; wherein m and n are positive integers and m>n.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a schematic diagram of telecommunications system 100 in the prior art.
FIG. 2 depicts a block diagram of the salient components of a station in accordance with the illustrative embodiment of the present invention.
FIG. 3 depicts a flowchart of the illustrative embodiment of the present invention.
FIG. 4 depicts a timeline of the frames transmitted in accordance with the illustrative embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 2 depicts a block diagram of the salient components of an IEEE 802.11 station in accordance with the illustrative embodiment of the present invention. Station 200 is capable of receiving a succession of frames from one or more sources and of segregating, queuing, and transmitting the frames based on their class of service.
Station 200 comprises: host interface 201 , receiver 202 , processor 203 , queues 204 - 1 to 204 -L, wherein L is a positive integer greater than one, and transmitter 205 , interconnected as shown.
Host interface 201 a circuit that is capable of receiving data and instructions from a host (not shown), in well-known fashion, and of forwarding them to processor 203 . Furthermore, host interface 201 enables station 200 to send data and status indicators to the host. It will be clear to those skilled in the art how to make and use host interface 201 .
Receiver 202 is a circuit that is capable of receiving frames from shared-communications channel, in well-known fashion, and of forwarding them to processor 203 . The frames include both data frames and control frames, such as request-to-send, clear-to-send, and acknowledgement frames.
Processor 203 is a general-purpose processor that is capable of performing the tasks described below and with respect to FIGS. 3 and 4 . It will be clear to those skilled in the art, after reading this specification, how to make and use processor 203 .
Queues 204 -i, for i=1 to L, are each first-in, first-out memories. Each of queues 204 - 1 through 204 -L are uniquely associated with application i, which is associated with a class of service. In accordance with the illustrative embodiment, each class of service is associated with one or more quality-of-service parameters (e.g., minimum throughput, maximum latency, etc.).
Each of queues 204 - 1 through 204 -L holds one or more frames pending transmission by station 200 on the shared communications channel. It will be clear to those skilled in the art how to make and uses queues 204 - 1 through 204 -L.
Transmitter 205 is a circuit that is capable of receiving frames from processor 203 , in well-known fashion, and of transmitting them on the shared communications channel.
FIG. 3 depicts a flowchart of the salient tasks performed by the illustrative embodiment of the present invention.
At task 301 , host interface 201 receives data and instructions from a host that indicate that the data is to be transmitted onto the shared-communications channel and that the data is associated with application i.
At task 302 , processor 203 receives the data from host interface 201 , divides the data into frames, in well-known fashion, and queues the frames onto the end of queue 204 -i.
At task 303 , station 200 acquires, in well-known fashion, an opportunity to transmit one or more frames associated with application i. In accordance with the illustrative embodiment, this opportunity enables station 200 to transmit a burst of up to M frames over shared-communications channel, where M is a positive integer.
Because station 200 operates in accordance with IEEE 802.11, station 200 becomes aware of a transmission opportunity in accordance with the distributed coordination function, the extended distributed coordination function, or the point coordination function. It will be clear to those skilled in the art how to make and use embodiments of the present invention that use different medium access control protocols.
Processor 203 continually determines from which one of queues 204 - 1 through 204 -L to next draw frames at the next transmission opportunity. In other words, conceptually queues 204 - 1 through 204 -L in station 200 are vying with each other for transmission opportunities. For example, the queue whose frames are to be transmitted at the next transmission opportunity can be based on, for example,
i. a round robin scheme, or ii. a random scheme, or iii. the current number of frames queued in queue 204 -i, or iv. the latency tolerance of application i, or v. the throughput requirements of application i, or vi. the current number of frames queued in queue 204 -i divided by N i .
It will be clear to those skilled in the art how to coordinate the selection of frames from queues 204 - 1 through 204 -L.
At task 304 , processor 203 determines the amount of time, T i , that is to be afforded to the transmission of frames for queue 204 -i at this transmission opportunity. The value of T i can be static or dynamic and can be the same for each station or different at each station. In accordance with the illustrative embodiment, each station determines its own values for T i for each queue, and the value is updated periodically or sporadically. In accordance with the illustrative embodiment of the present invention, the value for T i is based on:
i. the number of queues that have frames queued for transmission, or ii. the number of frames queued in queue 204 -i, or iii. the latency tolerance of application i, or iv. the throughput requirements of application i, or v. the current number of frames queued in queue 204 -i divided by N i , or vi. any combination of i, ii, iii, iv, and v.
For example, applications that are more latency intolerant might be given larger values of T i than applications that are less latency tolerant and applications that have greater throughput requirements might be given larger values of T i than applications that have lesser throughput requirements. It will be clear to those skilled in the art, after reading this specification, how to determine and use other criteria for establishing T i for application i.
To accomplish task 304 , processor 203 advantageously maintains a table that correlates T i and the number of frames queued in each queue to i. Table 1 depicts an illustrative version of this table.
TABLE 1
Queued Frame Database
Number of Frames Queued
i
in Queue 208-i
T i
1
13
23 ms.
2
7
25 ms.
. . .
. . .
L
42
7 ms.
At task 305 , processor 203 removes from queue 204 -i the lesser of:
i. the number of frames queued in queue 204 -i, and ii. N i , wherein N i is a positive integer,
and transmits them, as a contention-free burst, into the shared-communications channel, in well-known fashion. In accordance with the illustrative embodiment, the value of N i is based on:
i. the time needed to transmit the next N i data frames of queue 204 -i in T i seconds, or ii. the time needed to receive N i acknowledgement frames in T i seconds, or iii. the time needed for O(2N i ) short interval spaces, or iv. whether there will be a request-to-send frame, and if so, the time needed to transmit the request-to-send frame and receive the associated clear-to-send frame, or v. the time needed to retransmit any of the N i data frames due to transmission failures, or vi. any combination of i, ii, iii, iv, and v.
In accordance with the illustrative embodiment, the value of N i is less than the value of M because station 200 exercises self-restraint in the number of frames that it transmits at each transmission opportunity. This prevents the shared-communications channel from being monopolized or hogged by one application and lessens the amount of time that other applications have to wait before gaining access to the shared-communications channel.
When each station exercises such self-restraint, the applications that continually need access to the shared-communications channel—because of their relative latency intolerance—get the best opportunity to get the resources that they need.
FIG. 4 depicts a timeline of the frames transmitted in accordance with the illustrative embodiment of the present invention. Before time to, station 200 has obtained a transmission opportunity to transmit M frames into the shared-communications channel, and station 200 has decided to use that opportunity to send one or more frames associated with application i.
At time t o , station 200 transmits an IEEE 802.11 Request-to-Send frame (RTS 401 ) that comprises a duration field to a remote station, in well-known fashion. In accordance with the illustrative embodiment, the duration field of the Request-to-Send frame comprises a value that is based on the lesser of N i and the number of frames queued in queue 204 -i. Typically, the value in the duration field is also based on an estimate of the length of time necessary for the transmission of the Clear-to-Send frame, the data frames, the acknowledgement frames, and the short interframe spaces between the frames. As is well-known to those skilled in the art, this invokes the virtual carrier sense mechanism in the stations that receive the message to refrain from transmitting while station 200 is transmitting the frames associated with application i.
At time t 1 , the remote station transmits an IEEE 802.11 Clear-to-Send frame (CTS 402 ) in response to the Request-to-Send frame, in well-known fashion. The Clear-to-Send frame comprises a duration field comprises a value that is that is based on the lesser of N i and the number of frames queued in queue 204 -i. Typically, the value in the duration field is also based on an estimate of the length of time necessary for the transmission of the data frames, the acknowledgement frames, and the short interframe spaces between the frames.
At time t 403-1 , station 200 transmits an IEEE 802.11 data frame (Data 403 - 1 ), which results in the transmission at time t 404-1 of an IEEE 802.11 acknowledgement frame (ACK 404 - 1 ). Data frames 403 - 2 through 403 -N i are subsequently transmitted by station 200 and are interleaved with acknowledgement frames 404 - 2 through 404-N i . After the receipt of acknowledgement frame 404 -N i , another application is given the opportunity to transmit on the shared-communications channel.
It is understood that the above-described embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by those skilled in the art without departing from the scope of the invention. It is therefore intended that such variations be included within the scope of the following claims and their equivalents. | A technique is disclosed that enables latency-tolerant and latency-intolerant applications to intelligently share a shared-communications channel in a manner that seeks to satisfy the needs of all of the applications. In particular, the illustrative embodiment enables each application to be associated with a different class of service, wherein each class of service is associated with one or more quality-of-service parameters (e.g., minimum throughput, maximum latency, etc.). The illustrative embodiment then effectively apportions access to the shared-communications channel by regulating different degrees of bursting (i.e., the transmission of multiple frames at a single transmission opportunity) based on the class of service associated with the application. | 7 |
The invention relates to a device for carrying a replacement safety valve in a oil or gas well, particularly with a straddle structure for placement inside a damaged “Down Hole Safety Valve” nipple seal area.
FIELD OF THE INVENTION
Oil and gas well operators have been facing a challenge on how to avoid recompletion of wells where the nipple seal area inside the “Down Hole Safety Valve” (DHSV) is damaged, for instance due to well interventions or corrosion. Various methods have been used including standard insert “Wireline Retrievable Surface Controlled Subsurface Safety Valve” (WRSCSSV), with normal and oversize swell packing elements and honing of the upper and lower seal area prior to installing the insert.
To have the DHSV working properly is vital for the security of the well. If the DHSV is damaged the alternatives are to repair it using one of the above mentioned methods, or set a retrievable bridge plug above the DHSV area and leave the well shut in or do a recompletion of the well. To leave the well shut in is not a good option since it cannot be used for production or injection. To recomplete the well is very expensive since a rig is needed for this.
The above mentioned methods of repairing a damaged DHSV-nipple seal area's have failed or been too unsafe.
OBJECTS
The main object of the invention is to provide a generally improved device for carrying a replacement down hole safety valve.
A further object is to provide such a carrier with improved sealing properties. To this end, it is an object to provide improved sealing means to allow the insertion of a DHSV carrier in the most damaged wells.
It is also an object to improve the locking dog suspension to enhance the operation of the locking dogs. The locking dog suspension should be easy to install and maintain a reliable tension on the locking dogs.
THE INVENTION
The invention is defined in claim 1 . Further details are described in the sub-claims.
The device for inserting a replacement safety valve in a well tube, is based on a straddle structure for placement inside a damaged “Down Hole Safety Valve” nipple seal area, comprising a pair of sealing assemblies to be activated upon setting of the device to seal said nipple seal area, and a locking dog assembly for locking the device in the well tube, said elements being carried by a tubular mandrel.
The main novel features are that at least one of the sealing assemblies comprises an expandable element being activated by a pair of annular press elements.
The straddle device is using expandable elements which will allow the sealing elements of the sealing assemblies to be shaped according to the damaged surface inside in the seal area. In addition each element may be equipped with expanding anti-extrusion backup rings on both sides, trapping the element so it has nowhere to go when differential pressure is applied. The straddle device is using the existing nipple profile and no-go for anchoring and is equipped with locking dogs to fit this profile. A commercial safety valve, e.g. a Schlumberger WRDP valve, is made up to the bottom of the straddle, this is then operated by surface control line pressure.
By using a sealing assembly according to the invention, the ability of the DHSV carrier device to seal even badly damaged wells is enhanced.
The invention also comprises further novel features as stated in claims 2 to 7 , including a novel locking dog suspension.
The novel device according to this invention will bring several advantages over prior art technology:
Uses existing sealing surfaces of old DHSV Better sealing properties Anchoring module design maximizes locking contact area Sealing module construction enhances safety and reliability Suitable interface for replacement safety valve Easier mounting
LIST OF FIGURES
FIG. 1 shows a partly sectioned side view of an embodiment of a safety valve carrier according to the invention,
FIG. 2 shows a sectioned perspective view of the lower sealing assembly of the safety valve carrier of FIG. 1 , while
FIG. 3 shows a perspective view of the upper sealing assembly, with the locking dog housing removed to show the arrangement of the locking dogs.
DESCRIPTION OF EMBODIMENTS
FIG. 1 is showing a side view of the main part of a replacement safety valve carrier (straddle device) 11 , the drawing having on the left side an axial and radial cross section of the elements of this carrier. Centrally in the replacement safety valve carrier 11 a mandrel tubing 12 is arranged. The mandrel tubing 12 is connected to the outer part of the carrier 11 by a series of radial shear screws in the upper region. Further, the lower end of the mandrel tubing 12 is connected with threads 14 to a tubular sleeve or nose, which is carrying the replacement safety valve not shown. The replacement safety valve may be of prior art design.
The replacement safety valve carrier 11 has a tubular structure carrying
a lower sealing assembly 15 , an upper sealing assembly 16 , and a locking dog assembly 17 arranged adjacent to the upper sealing means 16 on its upper side.
The lower and the upper sealing assemblies 15 , 16 are providing a straddle structure.
According to the invention, the lower sealing assembly 15 and the upper sealing assembly 16 , comprise multiple elements.
The Lower Sealing Assembly
In FIG. 2 an embodiment of a lower sealing assembly 15 is shown. The lower sealing assembly 15 comprises a lower and an upper cone ring 19 , 20 respectively, arranged on a tubular lower sealing mandrel 21 . Between the lower and the upper cone rings, an annular expandable sealing element 22 is arranged. The expandable sealing element 22 has a trapezoidal section with radially diverging sides and being made of a resilient material, such as HNBR.
The tubular mandrel 21 is facing the mandrel tubing 12 and being connected to a sleeve 25 connecting it to a corresponding upper sealing mandrel 26 carrying the upper sealing assembly 16 . ( FIG. 1 )
The lower sealing mandrel 21 is comprising a sleeve 21 A carrying a lower nut mandrel 27 which is slidable in an annular recess 28 in a lower sealing backup housing 29 . The upper end of the lower sealing backup housing 29 engages the lower sealing cone ring 19 with an intermediate annular lower sealing backup 30 .
Similarly, an annular upper sealing backup 31 is arranged between the upper cone ring 20 and a upper part 21 B of the lower sealing mandrel 21 functioning as an upper sealing backup housing.
The sealing backups 30 and 31 each comprises an annular row of overlapping arched sealing backup elements 30 A and 31 A, respectively. Each backup element 30 A and 31 A comprises an outer sealing part 30 B and 31 B and an inner leg 30 C and 31 C.
The sealing backups 30 and 31 are attached to the lower sealing backup housing 29 and the upper sealing backup housing 21 B respectively, with ten bolts 32 each. Each spring bolt 32 is carrying a set of dish springs 33 .
The head 32 A of each bolt 32 has threads for engaging radial holes in the respective housings, being locked by radial locking screws 328 . The shanks of the bolts 32 are sliding in an opening in the leg 30 C and 31 C respectively, of the associated backup element 30 A and 31 A.
The expandable sealing element 22 is activated by the relative axial movement of the lower sealing backup housing 29 and the upper sealing backup housing 21 B at the setting of the device according to the invention.
The Upper Sealing Assembly
The upper sealing assembly 16 is corresponding generally to the lower sealing assembly 15 , having an expandable sealing element 34 ( FIG. 1 ).
The Sealing Backup Assembly
Each sealing backup assembly 30 and 31 comprises an annular chain of ten sealing backup elements 30 A and 31 A, respectively. Each sealing backup element comprises an outer, arched sealing backup part 30 B and 31 B, respectively, with a circumferential wing 44 on one side and a corresponding slot 45 on the other to allow overlapping of neighboring sealing backup elements. Thus the sealing backup elements will have a closing annular face against the outer rim of the expandable sealing element 22 , 34 , to restrict the axial expansion of the sealing element.
The Locking Dog Assembly
To lock the device according to the invention in the well tube, an annular row of nine locking dogs 61 are arranged over the upper sealing assembly 16 . The locking dogs 61 are arranged in openings 62 in a locking dog housing 63 . The locking dog housing 63 is carrying an axially slideable sleeve 65 . The lower end of the sleeve 65 has a chamfered face 66 facing the upper end of the locking dogs 61 to press them radially outward when setting the device.
In FIG. 3 , the locking dog housing 63 of FIG. 1 is omitted for clarity.
Each of the locking dogs 61 being a block with chamfered lower and upper edges 67 , 68 , is carried by a pair of axial torsion springs 69 , 70 . Each torsion spring 69 , 70 has a central spring rod 73 . The lower end of this rod may have a C-leg 71 engaging a slot 72 in the side of the locking dog 61 . The connection of the torsion springs 69 , 70 to the locking dogs 61 may have other suitable embodiments.
The central rods 73 of the torsion springs 69 , 70 are extending through a longitudinal slot 74 in the sleeve 65 .
At the upper end, each torsion spring 69 , 70 has a L-leg 75 extending into an annular slot 76 of the locking dog housing 65 . The width of the annular slot 76 is dimensioned to take the movement of the L-legs 75 between the end positions, from setting to locking.
The torsion springs 69 , 70 are pressing the locking dogs 61 inward. In the set position of the device according to the invention, with the no-go 64 engaging a shoulder in the tubular safety valve housing 18 , the locking dogs 61 are forced radially outward by the chamfered lower end 66 of the locking dog cone housing 65 .
The arrangement of the locking dogs 61 is making the elements easy to manufacture. The locking dogs according to the invention will have a larger area of contact than prior art locking dogs. Additionally, the torsion springs, acting in pairs, will provide balanced forces acting on the locking dogs. The mounting of the torsion springs 69 , 70 is easy.
The device according to the invention is providing a path for hydraulic fluid to the replacement safety valve through a radial hole 77 in the upper backup housing 21 B and an axial hole 78 in the lower part of the device. Said holes 77 and 78 are interconnected by the sleeve 21 .
The upper part of the device comprises a tubular extension 79 of the sleeve 65 with an upper fishing neck 80 . The design of the connection of the extension 79 to the mandrel 12 belongs to prior art technology. | Device for carrying a replacement safety valve in a well tube, with a straddle structure for placement inside a damaged “Down Hole Safety Valve” nipple seal area. It is comprising a pair of sealing assemblies ( 15, 16 ) to be activated upon setting of the device to seal said nipple seal area, and a locking dog assembly ( 17 ) for locking the device in the well tube, said elements being carried by a tubular mandrel ( 12 ). At least one of the sealing assemblies ( 15, 16 ) comprises a expandable element ( 22; 34 ) being activated by a pair of annular press elements ( 19, 20 ). | 4 |
BACKGROUND OF THE INVENTION
Freezeless wall hydrants and faucets have long been in existence. They characteristically have a fluid closure valve located in the end of an inlet pipe located within the wall or a warmer interior area of the building of which the wall is a part. This closure valve is operated by an elongated rod connected to an exterior handle. The freezeless characteristics of the hydrant are caused by the closure valve shutting off the flow of water within the wall or building at a freezing temperature, with the residual water in the inlet pipe flowing by gravity outwardly through the conventional outlet drain of the hydrant.
The foregoing structure works very successfully except in situations where a hose or the like is attached to the outlet drain of the hydrant, whereupon the residual water is not able to easily flow by gravity out of the hydrant when the closure valve connected to the pressurized water is closed. With a hose attached during freezing weather, the residual water freezes within the hydrant, and the inlet pipe or related components thereupon rupture from the freezing conditions within the hydrant.
It has in recent times been recognized that the rupture of such a hydrant under freezing weather conditions does not take place because of the frozen water in the hydrant. Rather, the rupture results from the ice imposing severe pressure on the captivated non-frozen fluid in the inlet pipe. Thus, the increased pressure on this water by the expanded ice is the principal cause for the rupture of the hydrant.
Accordingly, it is a principal object of this invention to provide a freezeless wall hydrant which has the ability to drain at least some of the residual water in a hydrant when, under freezing conditions, the residual water towards the exterior part of the hydrant freezes by reason of a hose or the like being attached to the discharge nozzle.
It is a further object of this invention to provide a relief valve for the captured residual water under the foregoing conditions to escape back towards the supply of pressurized water when the frozen water in the exterior of the hydrant creates excessive pressure on the remainder of the residual water in the hydrant.
These and other objects will be apparent to those skilled in the art.
SUMMARY OF THE INVENTION
A freezeless wall hydrant has an inlet pipe with one end connected to a source of pressurized water, a water discharge conduit, and an elongated control rod extending through the inlet pipe to open and close a fluid valve. A bore is inserted through the fluid valve with the bore being in communication with both the source of pressurized water and the interior portion of the inlet pipe. A check valve is placed in the bore of the valve body and is spring loaded to open only when extreme water pressure within the inlet valve lifts a spring loaded ball to permit the highly pressurized water to move through the bore in the valve body and be relieved as it escapes rearwardly into the original source of pressurized water. The check valve is enclosed within a cylindrical housing and is force-fit into the bore of the valve body. The spring has a strength that it will open the bore to fluid flow in a rearward direction only when the pressure within the outlet portion of the inlet conduit is greater than that of the pressurized source of water normally located upstream from the valve closure. Other alternative ways of relieving the water pressure created by the presence of ice exist and include, for example, eliminating the spring and allowing water to dwell on each side of the ball whereupon high pressure on one side of the ball will allow the ball to move to balance that pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of the hydrant of this invention;
FIG. 2 is a large scale sectional view of the valve body which controls flow of pressurized water through the hydrant;
FIG. 3 is a sectional view similar to that of FIG. 2 but shows the check valve of this invention inserted into the valve body of FIG. 4 along with the inner end of the control rod being attached to the valve body;
FIG. 4 is an enlarged scale sectional view through the check valve that is force fed into the bore of the valve body of FIGS. 2 and 3;
FIG. 5 is a perspective view of the check valve of FIG. 4 shown at a smaller scale; and
FIGS. 6-10 are views similar to FIG. 4 but show alternative structure to relieve high water pressure caused by ice in the hydrant.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The hydrant 10 in FIG. 1 has an elongated hollow water inlet tube 12 which has an interior end 14 and an exterior end 16. A hollow valve fitting 18 is rearwardly secured to the interior end 14 of tube 12 and has a threaded end 20 adapted to be secured to a conduit connected to a source of pressurized fluid (not shown). The fitting 18 has an interior end 22 with external threads 24 and which terminate in a valve seat 26.
A casting member 28 has a conventional vacuum breaker 30 secured thereto and is rigidly connected to the exterior end 16 of inlet tube 12. A conventional fluid drain conduit 32 is located within casting member 28 and is in communication with the interior of tube 12. Conventional threads 34 are located on the discharge end of conduit 32 to receive a conventional hose or the like. Casting member 28 also has a threaded aperture 36 which is adapted to receive a conventional bushing 38 which in turn receives packing 40 which is held in tight engagement with bushing 38 by packing washer 42 (FIG. 1).
Adjacent the interior end 22 of valve fitting 18 is a valve body 44 adapted for longitudinal movement in the interior end 14 of tube 12. Valve body 44 has an interior end 46, an exterior end 48 and an elongated center bore 50 extending therethrough (FIG. 2). A first annular shoulder 52 is located within center bore 50. Threaded arms 54 extend rearwardly from the body 44 and are adapted to threadably engage the threads 24 on the interior end 22 of valve fitting 18. A second annular shoulder 56 is located within center bore 50 rearwardly of the first annular shoulder 52. A third shoulder surface 58 is located around the inner end of bore 50 and functions as the bottom of recess 60 in which a conventional valve seating member 62 is located (FIG. 3). A rivet or screw 64 has a hollow center bore 66 and extends through valve seating 62 to be rigidly secured by either friction or threads to the interior end of bore 50.
A recess 68 is located in valve body 44 adjacent the outward end of bore 50. A plurality of spaced spline teeth 70 extend outwardly from recess 68. A conventional check valve member 72 extends around the spline teeth 70 and are adapted to engage the interior surface of the fluid inlet tube 12. The check valve member 72 conventionally permits fluid flow only in a direction towards the drain conduit 32, but prevents fluid flow in the inlet pipe in opposite direction.
A conventional elongated rod control 74 is located within the inlet pipe 12 and has a rearward end 76 and a forward end 78. Spline grooves 80 are formed in the rearward end 76 of the rod control and are adapted to engage the spline teeth 70 located at the forward end of the body 44. A conventional handle wheel 82 is mounted on the forward end 78 of rod control 74 and is held in place by conventional screw 84.
As best shown in FIG. 4, a hollow valve body member 86 with a forward end 88 and rearward end 90 terminates at its rearward end in sleeve 92. Sleeve 92 has a bore 94 and is in communication with the hollow interior of body member 86 and the open forward end 96 of the body member. A spherical ball 98 is located in the forward end 88 of valve body 86 and is yieldingly held against the shoulder 52 to seal the bore 50 under normal operation of the hydrant. The compression spring 100 is compressed between ball 98 and the outer end of sleeve 92. The compressive strength of the spring is sufficient to hold the ball 98 in a sealing condition against shoulder 52 at all times when the pressure of fluid moving into inlet pipe 12 is no greater than the pressurized water flowing into the hydrant when the valve seating member 62 is in spaced condition with respect to the valve seat 26 (FIG. 1). In operation, the handle 82 is rotated to rotate rod 74 in a first direction to open the valve body 44 from sealing engagement with the valve seat 26 of the valve fitting 18. Pressurized water than flows through the hollow interior of valve fitting 18, thence around the valve body member 44 and the check valve 72, and thence through the interior body of the inlet tube 12 and thence outwardly through the fluid drain conduit 32. The flow of pressurized fluid through the hydrant is terminated when the rod 74 is rotated in the opposite direction to cause the valve seating member 62 to close on the valve seat 26.
In the event that a hose is attached to the fluid drain conduit 32 in freezing temperatures, the residual water which ordinarily would flow out of the conduit 32 if the hose were not attached when the valve member 42 is in a closed condition will be captured within the conduit 32 and the interior of tube 12. This residual captured water will first begin to freeze in the discharge conduit 32 and adjacent the exterior end 16 of tube 12. The presence of ice in that portion of the hydrant will cause excessive pressure possibly as high as 4,000 psi in unfrozen residual water in the end 14 of tube 12. This is because water volume expands by about 8% as it turns to ice. Ordinarily, water under that much pressure would rupture at least the inlet pipe 12. However, with the present invention, this increased pressure exerted on the residual water in the inlet pipe 12 occasioned by the formation of ice in the exterior end thereof will exert pressure on ball 98 and will compress the spring 100. Thus, the highly pressurized water will flow rearwardly through opening 96 in body 86, thence through the hollow interior of the body member 86, thence through the bore 94 in sleeve 92, thence through the hollow bore 66 and thence into the hollow interior of valve fitting 18. This flow of water will take place even though the valve fitting 18 may be filled with normally pressurized water. Again, with the force-fit relationship of the body member 86 within the bore 50 of body member 44, the ball 98 will not yield under normal pressurized water, but will yield and open only under the excessive pressure caused by the freezing in the hydrant as described above.
DESCRIPTION OF ALTERNATIVE EMBODIMENTS OF THE INVENTION
FIGS. 6-10 show alternative structures for use in lieu of valve body member 86.
In FIG. 6, a modified valve body 86A includes a ball 98 and spring 100 as shown in FIG. 4, but the spring 100 is contained on one end by wall 102. An aperture 94A is in wall 102 to permit the escape of water therethrough if high efficient pressure moves ball 98 off of seat 104 surrounding aperture 106.
The device in FIG. 10 is similar to that of FIG. 6 except that the spring 100 has been eliminated from the valve body 86B. Normally, the water pressure on each side of ball 98 is the same. The pressure of inlet water will normally cause ball 98 to close on seat 104. However, if water pressure exerts excess pressure on the right-hand side of ball 98 through aperture 106, ball 98 will be unseated from seat 104 and the device will then relieve that excessive fluid pressure in the same manner as did the devices of FIGS. 4 and 6.
The device of FIG. 7 is similar to that of FIG. 4 except that the sleeve 92 is press fit into the enlarged shoulder structure 108 of valve body 86C. The forward end of body 86C is the same as in body 86B of FIG. 10 with ball seat 104A and aperture 106A. The device of FIG. 7 functions, as does the device of FIGS. 4 and 6.
The device of FIG. 8 is the same as that shown in FIG. 7, but the valve body 86D of FIG. 8 has no shoulder structure 108.
The device of FIG. 9 is similar to that of FIG. 6, except that no valve body 86A is used. Rather, the spring 100 and ball 98 are mounted in cavity 110 in conjunction with the valve seating member 62, and screw 64 with hollow center bore 66 of FIG. 3.
All of the alternative embodiments shown in FIGS. 6-10 allow the escape of fluid under high pressure to escape through the dislodged ball 98 for return to the water supply line when fluid pressure conditions on the other side of the ball are excessive.
Thus, from the foregoing, it is seen that this invention will keep the ordinary freezeless hydrant from becoming ruptured whenever a hose or the like is inadvertently left on the discharge conduit thereof. This successful result takes place because the formation of ice in such a hydrant under those conditions will permit the back flow of residual water in the hydrant to move through the otherwise closed hydrant valve into the original source of pressurized water. This relief of pressure will prevent the hydrant from rupturing under the freezing conditions. It is therefore seen that this invention will achieve all of its stated objectives. | A freezeless wall hydrant/faucet has an inlet pipe with one end connected to a source of pressurized water, a water discharge conduit, and an elongated control rod extending through the inlet pipe to open and close a fluid valve. A bore is inserted through the fluid valve with the bore being in communication with both the source of pressurized water and the interior portion of the inlet pipe. A check valve is placed in the bore of the valve body to open only when extreme water pressure within the inlet valve moves a seated ball to permit the highly pressurized water to move through the bore in the valve body and be relieved as it escapes rearwardly into the original source of pressurized water. | 4 |
PRIORITY
[0001] This application claims the priority benefit of French Patent Application No. 13/58324, filed on Aug. 30, 2013, the contents of which is hereby incorporated by reference in its entirety to the maximum extent allowable by law.
FIELD OF THE INVENTION
[0002] The present disclosure relates to the forming of electronic components inside and on top of single-crystal gallium nitride substrates. It more specifically relates to a method for treating or preparing a doped single-crystal gallium nitride substrate for the forming of electronic components inside and on top of this substrate.
BACKGROUND
[0003] Electronic components, and especially power components such as Schottky diodes, have already been formed by using doped single-crystal gallium nitride as a semiconductor material.
[0004] Conventionally, gallium nitride substrates may be solid substrates, of a thickness ranging from a few tens to a few hundreds of micrometers, or appear in the form of a gallium nitride layer having a thickness of a few micrometers coating a support of another material, for example, a silicon support.
[0005] Whether they are solid (freestanding) or supported by a support material, gallium nitride substrates generally have dislocations, corresponding to discontinuities in the organization of their crystal structure. Such dislocations may raise issues in certain applications.
SUMMARY
[0006] Thus, an embodiment provides a method of treating a doped gallium nitride substrate of a first conductivity type, having dislocations emerging on the side of at least one of its surfaces, comprising: a) forming, where each dislocation emerges, a recess extending into the substrate from the at least one surface; and b) filling the recesses with doped gallium nitride of the second conductivity type.
[0007] According to an embodiment, step b) comprises a step of epitaxial deposition, on the at least one surface, of a doped single-crystal gallium nitride layer of the second conductivity type, followed by a step of planarization of this layer.
[0008] According to an embodiment, during the planarization step, the gallium nitride layer is removed everywhere except from the recesses.
[0009] According to an embodiment, the planarization step comprises a chem.-mech. polishing.
[0010] According to an embodiment, at step a), the recesses are formed by means of a wet etching solution applied on the at least one surface.
[0011] According to an embodiment, the etching solution comprises potassium hydroxide at a concentration in the range 10 to 90%.
[0012] According to an embodiment, the etching solution comprises phosphoric hydroxide at a concentration in the range 10 to 90%.
[0013] According to an embodiment, at step a), the recesses are formed by means of a chlorine plasma.
[0014] According to an embodiment, at step a), the forming of the recesses comprises a step of annealing the substrate at a temperature greater than or equal to 830° C.
[0015] According to an embodiment, the first and second conductivity types respectively are type N and type P.
[0016] Another embodiment provides a method for manufacturing a gallium nitride semiconductor component, comprising: treating, according to the above-mentioned method, a doped gallium nitride substrate of a first conductivity type, having dislocations emerging on the side of at least one of its surfaces; and depositing at least one conductive, semiconductor, or insulating layer on the at least one surface.
[0017] According to an embodiment, the component is a Schottky diode, and the conductive, semiconductor, or insulating layer is a metal layer.
[0018] The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIGS. 1A to 1D are cross-section views schematically illustrating an example of an embodiment of a method for treating a gallium nitride substrate for the forming of electronic components inside and on top of this substrate.
[0020] For clarity, the same elements have been designated with the same reference numerals in the different drawings and, further, as usual in the representation of integrated circuits, the various drawings are not to scale.
DETAILED DESCRIPTION
[0021] In the rest of the present description, unless otherwise indicated, terms “on the order of”, “approximately”, “substantially” and “around” mean to within ten percent.
[0022] FIG. 1A schematically shows an N-type doped single-crystal gallium nitride substrate 101 (GaN). In this example, substrate 101 is formed on a silicon support 103 . The described embodiments are however compatible with solid gallium nitride substrates (freestanding).
[0023] As appears in FIG. 1A , substrate 101 comprises dislocations. Some of these dislocations, referred to as 105 in the drawing, emerge on the side of the surface of substrate 101 opposite to silicon support 103 , which will be called hereafter, by convention, the upper surface of substrate 101 .
[0024] Emerging dislocations 105 are capable of causing malfunctions in electronic components where one or several conductive, semiconductor, or insulating layers (not shown) coat the upper surface of substrate 101 . They are particularly problematic when a Schottky diode comprising a Schottky contact between substrate 101 and a conductive layer (not shown), for example, made of metal, coating the upper surface of substrate 101 , is desired to be formed. Indeed, the contact areas between dislocations 105 and the conductive layer form areas of lower potential barrier in the Schottky junction, which locally decreases the reverse withstand voltage of the diode and increases reverse leakage currents with respect to a diode comprising no dislocation emerging on the Schottky contact.
[0025] It is here provided to treat substrate 101 to overcome all or part of the disadvantages linked to the presence of dislocations 105 emerging on its upper surface side.
[0026] To achieve this, it is provided to open an upper portion of dislocations 105 emerging on the upper surface side of substrate 101 , that is, to form in substrate 101 , on its upper surface side, recesses in front of dislocations 105 , and then to fill the openings with gallium nitride of a conductivity type opposite to that of the substrate.
[0027] FIG. 1B illustrates a step of forming recesses 107 in substrate 101 , on the upper surface side thereof, opposite to dislocations 105 emerging on the upper surface side of the substrate.
[0028] In a preferred embodiment, to form recesses 107 , the upper surface of substrate 101 is placed in contact with a chemical etching solution capable of preferentially etching the areas of substrate 101 surrounding dislocations 105 over the areas of substrate 101 comprising no dislocations emerging on the upper surface of the substrate. A solution based on potassium hydroxide (KOH) may for example be used. As a variation, a solution based on orthophosphoric acid (H 3 PO 4 ) may be used. To obtain a marked etching of the substrate areas surrounding dislocations 105 , the concentration of the etching agent in the solution is preferably relatively high, for example, in the range 10% to 90% in the case of potassium hydroxide or of orthophosphoric acid.
[0029] As a variation, to form recesses 107 , the upper surface of substrate 101 may be submitted to an etching plasma, for example, a chlorinated or argon plasma or any other appropriate etching gas.
[0030] As a variation, to form recesses 107 , substrate 101 may be annealed at a relatively high temperature, preferably higher than 830° C., which causes an opening of the upper portion of dislocations 105 emerging on the upper surface of the substrate.
[0031] More generally, any method capable of forming recesses 107 extending in substrate 101 from its upper surface, opposite to dislocations 105 , may be used.
[0032] As an example, recesses 107 extend in substrate 101 from its upper surface down to a depth approximately in the range from 0.2 to 10 μm, and have a diameter or a width approximately in the range from 0.001 to 0.5 μm.
[0033] In the shown example ( FIGS. 1C and 1D ), to fill recesses 107 , it is provided to form, by epitaxy, a doped gallium nitride layer of a conductivity type opposite to that of the substrate (that is, a P-type layer in this example) coating the upper surface of substrate 101 , and then to planarize this layer to remove it everywhere except inside of recesses 107 .
[0034] FIG. 1C illustrates a step, subsequent to the step of forming of recesses 107 , of epitaxial deposition of a P-type doped single-crystal gallium nitride layer 109 over the entire surface of substrate 101 . Layer 109 is for example formed by chemical vapor deposition, according to a method currently called metal organic chemical vapor deposition, MOCVD, in the art. As a variation, layer 109 is formed according to a method currently called MBE (“Molecular Beam Epitaxy”) in the art or by a method currently called RPCVD (“Remote Plasma Chemical Vapor Deposition”) in the art. Any other method capable of depositing a doped gallium nitride layer of a conductivity type opposite to that of substrate 101 may be used. To obtain a P-type doping, magnesium may for example be provided in the deposition source. The doping level of layer 109 is preferably greater than that of substrate 101 . As an example, substrate 101 has a doping level in the range 10 15 to 2*10 16 atoms/cm 3 , and layer 109 has a doping level greater than 10 17 atoms/cm 3 .
[0035] The thickness of layer 109 is preferably selected to totally fill recesses 107 , for example all the way to the upper surface level of substrate 101 . As an example, layer 109 has a thickness in the range 0.2 to 15 μm.
[0036] FIG. 1D illustrates a planarization step, following the deposition of layer 109 , during which layer 109 is thinned from its upper surface, until it is totally removed opposite to the regions substrate 101 which have not been recessed at the step described in relation with FIG. 1B , to clear the access to the upper surface of substrate 101 in these regions. During the planarization step, the P-type doped gallium nitride of layer 109 is removed everywhere except from recesses 107 . A small thickness of substrate 101 may possibly be removed during the planarization, to guarantee the removal of any P-type doped gallium nitride residue from the upper surface of the regions of substrate 101 which have not been recessed at the step described in relation with FIG. 1B . The planarization is unterrupted before reaching the bottom of recesses 107 , to keep P-type doped gallium nitride areas forming an interface between dislocations 105 and the upper surface of the semiconductor structure. In a preferred embodiment, the planarization step of FIG. 1D is performed at least partly and preferably totally by chem.-mech. polishing (CMP).
[0037] An advantage of the embodiment described in relation with FIGS. 1A to 1D is that it enables to avoid for dislocations of the substrate to directly emerge on a surface of the substrate intended to receive conductive, semiconductor, or insulating layers of a semiconductor gallium nitride component.
[0038] This embodiment is particularly advantageous for the forming of a Schottky diode comprising a Schottky contact between substrate 101 and a conductive layer (not shown), for example, made of metal, coating the upper surface of substrate 101 . Indeed, the presence of the P-type doped local interface regions enables to avoid a drop of the potential barrier at dislocations 105 when the diode is reverse-biased. This enables to improve the reverse withstand voltage of the diode. This further enables to decrease reverse current leakages in the diode via dislocations 105 . It should be noted that in the case of a Schottky diode, the doping level of the P-type regions should be sufficiently high for the reverse withstand voltage of the diode to take place at the level of the Schottky interface, and not at the level of the PN diodes formed between the P-type gallium nitride filling recesses 107 and substrate 101 .
[0039] Specific embodiments have been described. Various alterations, modifications, and improvements will readily occur to those skilled in the art.
[0040] In particular, the above-described embodiments are not limited to the forming of a diode comprising a Schottky contact between substrate 101 and a conductive layer coating the upper surface of the substrate. The method for treating substrate 101 described in relation with FIGS. 1A to 1D may be used for the forming of other gallium nitride semiconductor components, for example, PN power diodes, bipolar power transistors, light-emitting diodes, heterojunction transistors, heterojunction diodes, or any other gallium nitride component capable of taking advantage of the provided treatment of the dislocations emerging on the upper surface side of the substrate.
[0041] Further, the described embodiments are not limited to the treatment of only the dislocations emerging on the upper surface side of the substrate. Thus, in the case of a solid (freestanding) substrate, it will be within the abilities of those skilled in the art to adapt the method described in relation with FIGS. 1A and 1B to treat not only dislocations emerging on the upper surface side of the substrate, but also dislocations emerging on the lower surface side of the substrate if this is advantageous for the envisaged use of the substrate.
[0042] Further, the described embodiments are not limited to the treating of an N-type doped gallium nitride substrate, but may be applied to the treating of a P-type doped substrate. In this case, it will be provided to fill with N-type doped gallium nitride recesses 107 formed at the step of FIG. 1B .
[0043] Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto. | A method is for treating a doped gallium nitride substrate of a first conductivity type, having dislocations emerging on the side of at least one of its surfaces. The method may include: a) forming, where each dislocation emerges, a recess extending into the substrate from the at least one surface; and b) filling the recesses with doped gallium nitride of the second conductivity type. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Present Disclosure
[0002] This disclosure relates generally to hoisting straps and methods for their use in lifting heavy objects, and more particularly to a strap configuration and a method for using the strap configuration in lifting a heavy object into a confined space.
[0003] 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
[0004] Dolezych et al, U.S. Pat. No. 4,915,434, discloses an apparatus to shorten and/or fasten flat belts or straps for wrapping and hoisting a load. The apparatus includes a vertical base plate having a crane lug located in its upper portion. Also, at least three deflectors with free ends are mounted in spaced apart relation on the plate so as to project generally perpendicularly therefrom. The free ends of the straps or belts are inserted into the apparatus and pulled between and looped about the deflectors in a meandering fashion to affix the belts to the apparatus before hoisting the load.
[0005] Williams, U.S. Pat. No. 7,165,795, discloses a device for use in lifting an air conditioning compressor from an air conditioning unit for servicing or replacement of the compressor. The lifting device is also useful for setting a replacement compressor back into place in an air conditioning unit. It simplifies the task of lifting the compressor by allowing the lifting to be performed at a height that reduces risk of bodily injury and thereby allows the task to be more easily performed. The device is usable by either a single person or by two people if the weight of the particular compressor calls for two people.
[0006] The related art described above discloses lifting equipment including lifting straps, hoists and associated mechanical components. However, the prior art fails to disclose a strap assembly and a method of its use that allows an individual, working alone, to raise a heavy object quickly and efficiently and to place the object into a confined space. The present disclosure distinguishes over the prior art providing heretofore unknown advantages as described in the following summary.
BRIEF SUMMARY OF THE INVENTION
[0007] This disclosure teaches certain benefits in construction and use which give rise to the objectives described below.
[0008] The use of lifting straps to hoist a heavy object, including furnaces and air conditioning units, is commonly known. Often, such loads are installed into attics of homes. This can create a problem when the home has a peaked roof and the entryway into the attic is located in a ceiling area underneath a low point of the roof rafters because there may not be enough room to lift the load high enough to clear the floor of the attic. In addition, attic entryways are typically too narrow to pass many loads lengthwise so that the load must be hoisted with its long dimension held vertically.
[0009] In such homes, the process of hoisting the load into an attic space can be hazardous to personnel due to the danger of dropping the load and of straining muscles due to off center lifting due to the limited space, and it can be time consuming, often requiring the labor of two or more persons for several hours. Techniques in common use for such lifting include manhandling the load into the attic space using ladders, and lifting the load from below using jacking devices. Both of these approaches are dangerous, time consuming and expensive. A hoist is usually not used since it further limits the vertical lifting range of the load.
[0010] The present invention solves this problem by using a custom strap assembly that is able to secure the load for being lifted by a hoist while overcoming the vertical limitations of such a lift by enabling partial unstrapping to tilt the load while still holding it by the strap and the hoist. Such a strap configuration is able to be quickly and easily employed by wrapping it about the load in a manner that the weight of the load is supported by one of the straps, a lifting strap, and laterally secured on the lifting strap by at least two lateral (belly-band) straps. Quick engagement of the lateral straps around the load is achieved by the use of hook-and-loop (Velcro® type) fastening surfaces on the lateral straps.
[0011] To accommodate taller or shorter loads, the vertically oriented lifting strap may also provide hook-and-loop fastening surfaces at its ends so as to enable lengthening or shortening the overall length of the lifting strap while still enabling the formation of loops at its ends for engagement with a hook of a hoisting device.
[0012] In addition, the present invention discloses a method of hoisting a load into a confined space such as an attic of a home. It should be noted that the advantages of the present invention are not limited to hoisting loads into confined attic spaces; but rather it can be used to hoist loads with a very broad range of weights and configurations and in the widest possible number of different situations.
[0013] A primary objective inherent in the above described apparatus and method of use is to provide advantages not taught by the prior art.
[0014] Another objective is to provide a lift strapping apparatus that can be used on a wide range of loads having various shapes and sizes.
[0015] A further objective is to provide such a lift strapping apparatus that can secure a large object, quickly, and with relative ease.
[0016] A further objective is to provide such a lift strapping apparatus that is relatively lightweight and compact, enabling it to be easily stored and transported when not in use.
[0017] A still further objective is to provide such a lift strapping apparatus that reduces the amount of labor and number of persons necessary to hoist a heavy object.
[0018] Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described apparatus and method of its use.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0019] Illustrated in the accompanying drawing(s) is at least one of the best mode embodiments of the present invention In such drawing(s):
[0020] FIG. 1 is a perspective view of the present invention;
[0021] FIG. 2 is a partial side elevational view thereof showing an alternate Y-shaped portion of the strap assembly thereof and a platform attached thereto;
[0022] FIG. 3 is a perspective view of the apparatus of FIG. 1 shown engaging a load;
[0023] FIG. 4 is a plan view of the apparatus of FIG. 2 ; and
[0024] FIGS. 5 , 6 and 7 are elevational views depicting stages of a method, using the presently described apparatus, of vertically lifting a load into a confined space through an opening where the load is tilted to transfer it from the strap assembly to a support surface, including: hoisting the load, as shown in FIG. 5 , tilting the load, as shown in FIG. 6 , and placing the load, as shown in FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0025] The above described drawing figures illustrate the described apparatus and its method of use in at least one of its preferred, best mode embodiment, which is further defined in detail in the following description. Those having ordinary skill in the art may be able to make alterations and modifications to what is described herein without departing from its spirit and scope. Therefore, it must be understood that what is illustrated is set forth only for the purposes of example and that it should not be taken as a limitation in the scope of the present apparatus and method of use.
[0026] Described now in detail is a lifting strap assembly apparatus for hoisting a heavy load. The strap assembly 2 comprises a plurality of elongated flexible straps, each having opposing flat surfaces 5 and 6 and each terminating at opposing ends 7 and 8 as shown in FIG. 1 . One of the straps, herein referred to as a lifting strap 10 , provides a closed loop 16 ( FIG. 3 ) at each of its opposing ends 7 and 8 . One or more further straps, herein referred to as lateral straps 20 , are either permanently or impermanently joined orthogonally at a medial location on the lifting strap 10 . When joined impermanently, the lateral straps 20 are joined to lifting strap 10 using hook and loop surface fasteners 25 in one embodiment, so that they are able to be repositioned on lifting strap 10 appropriately for different sized loads. The lateral straps 20 may alternately be permanently joined with the lifting strap 10 using stitching or other methods well known in the art.
[0027] As shown in FIG. 3 , each lateral strap 20 provides hook and loop surface fasteners 25 , at its opposing ends 7 and 8 . However, other suitable types of fasteners, such as threaded hardware, buttons or snaps, may be substituted. In FIG. 4 , the surface fasteners 25 are shown and labeled separately as 25 A and 25 B. This is to help illustrate how the surface fasteners engage with one another. Thus, each surface fastener 25 A engages with its corresponding surface fastener 25 B on the opposing end of lateral strap 10 . In an alternate embodiment, as shown in FIG. 1 , the surface fasteners 25 are only located on the lateral straps 20 to one side of the strap assembly 2 ; while on the other side, the lateral straps 20 are continuous.
[0028] As shown the lifting strap 10 may be formed into a closed loop 16 at its ends by folding its ends 7 and 8 and securing each end against itself using the hook and loop surface fasteners 25 . A hoist ring 12 may be secured within loops 16 to improve the ease by which a hoist hook 62 may be engaged with strap 10 . Please refer to FIGS. 5 and 6 which, however, do not depict the use of hoist rings 12 .
[0029] As shown in FIG. 2 , a rigid platform 30 may be engaged with the lifting strap 10 so that a load 40 may be stabilized. The platform 30 is preferably made of wood or other relatively lightweight rigid material. In addition, the lifting strap 10 may provide opposing Y-shaped portions 34 for engaging platform 30 with improved stability. In FIG. 4 , the platform 30 is permanently engaged with the lifting strap 10 .
[0030] As shown in FIG. 3 , specifically, each lateral strap 20 extends around the load 40 , in contact with all four side panels 42 , 44 , 46 and 48 , with the hook and loop surface fasteners 25 positioned on either side panel 42 or 46 or both. As shown, the lifting strap 10 is long enough to vertically encircle the load 40 while positioning its ends 7 and 8 formed as loops 16 somewhere above the load 40 , as shown in FIGS. 1 and 3 . The lateral strap(s) 20 are fixed to the lifting strap 10 so that with the lifting strap engaged with the load 40 , the lateral strap(s) 20 are positionable about the load 40 in a manner to stabilize the load 40 on the lifting strap 10 while joining the ends 7 and 8 of the lateral straps 20 on either one of panels 42 or 46 or both. This arrangement and intersection of orthogonal straps 10 and 20 with a parallelepiped shaped load 40 is then ideally suitable for lifting.
[0031] As shown in FIGS. 5-7 , the strap assembly 2 is used to vertically lift load 40 , typically in conjunction with a hoist 60 . In the preferred method of the present invention, the strap assembly 2 is used to lift load 40 , through an opening 52 into a confined space 50 such as an attic of a home. As shown in FIG. 5 , the load 40 is too long (vertical dimension) to clear the opening 52 before run out of hoist 60 . Because of the novel construction of strap assembly 2 , the upper lateral strap 20 may be opened while still supporting the load 40 on lifting strap 10 and stabilizing it using the lower lateral strap 20 , and the load 40 may be then tilted to one side, as shown in FIG. 5 , so as to enable pulling the load 40 onto surface 54 while supporting the full load 40 weight by hoist 60 .
[0032] The enablements described in detail above are considered novel over the prior art of record and are considered critical to the operation of at least one aspect of the apparatus and its method of use and to the achievement of the above described objectives. The words used in this specification to describe the instant embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification: structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use must be understood as being generic to all possible meanings supported by the specification and by the word or words describing the element.
[0033] The definitions of the words or drawing elements described herein are meant to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements described and its various embodiments or that a single element may be substituted for two or more elements in a claim.
[0034] Changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalents within the scope intended and its various embodiments. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. This disclosure is thus meant to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted, and also what incorporates the essential ideas.
[0035] The scope of this description is to be interpreted only in conjunction with the appended claims and it is made clear, here, that each named inventor believes that the claimed subject matter is what is intended to be patented. | A strap assembly for lifting a load has a plurality of elongated flexible straps that are joined together and configured in such as way as to enable relatively quick, easy securement of a large object so that it can be safely hoisted. In addition, the present invention discloses a method of hoisting a heavy object, such as an air conditioning unit, into a confined space such as an attic of a home. The strap assembly provides Velcro® type fastening elements enabling the strap assembly to be fitted to a wide range of loads. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a video display device comprising a spacial light modulator.
Video display devices comprising spacial light modulators have been attracting keen attention because of the high brightness of the projected picture as compared with that projected by a transmission type liquid crystal projector. The spacial light modulator is a key device of the video projection system for outputting a readout light, modulated in strength by a writing light, through reflection by an internal reflection layer.
The following, is a description of the structure and the operation of a prior art spacial light modulator. FIG. 10 shows the inside structure of a spacial light modulator 1. In FIG. 10, numeral 101 denotes a glass substrate in writing side; 102 is an electrode made of a transparent electro-conductive layer, such as an indium tin oxide (ITO) electrode, in writing side; 103 is a photodiode having pin construction comprised of amorphous silicon (hereinafter referred to as an a-Si photodiode), made up of three semiconductor layers in the following order from the side of writing light: a p-type layer 104, an insulation layer (i-layer) 105, and an n-type layer 106; 107 is an aluminum readout light reflection layer; 108 is an insulation layer of carbon in lattice form which splits the aluminum readout light reflection layer into small pieces in a longitudinal and lateral arrangement, breaking the conduction between the small pieces of light reflection layer located next to each other. Numeral 109 denotes a liquid crystal layer of ferroelectric material for controlling the tone of the picture, 110 is an ITO electrode in the readout light side, 111 is a glass substrate in the readout light side, 20 is a writing light, 22 is an incoming readout light, 23 is a reflected readout light, 2 is a reset pulse generating circuit for generating a reset pulse to be applied between the two ITO electrodes, 102 and 110, in order to drive the spacial light modulator.
The following is a description of the operation of a video display device comprising a spacial light modulator. When no voltage is applied to the liquid crystal layer 109, the reflected readout light 23 reflected by the aluminum readout light reflection layer 107 is outputted maintaining the same state of polarization as inputted from the glass substrate 111. When a voltage is applied to the liquid crystal layer 109 and the voltage is gradually increased, the polarization state of reflected readout light 23 reflected by the readout light reflection layer 107 gradually changes, and when the applied voltage exceeds a certain value the reflected readout light 23 is outputted with a completely opposite polarization.
The operation of a spacial light modulator 1 having an internal structure as shown in FIG. 10 is divided into two periods; a writing period for accumulating electrical charges in accordance with the strength of writing light 20, and a resetting period for removing the accumulated electrical charges.
In a case where the ITO electrode 110 on the side of the incoming readout light 22 is grounded as shown in FIG. 10, a negative voltage is applied to the ITO electrode 102 on the side of the writing light. Namely, the a-Si photodiode 103 is reverse biased. During a writing period when there is no writing light 20, almost all of the voltage applied to the two ITO electrodes, 102 and 110, is applied to the a-Si photodiode 103, with almost no voltage on liquid crystal layer 109. Under such state, the readout light 22 incoming to the spacial light modulator 1 is reflected as is, without a shift in the state of polarization, and outputted as reflected readout light 23. When there is writing light 20, electrons at the border between the p-type layer 104 and the insulation layer 105 of a-Si photodiode 103, are excited by the writing light 20. These electrons are pulled by positive potential and move towards the liquid crystal layer 109. As the result, in the vicinity of respective surfaces of liquid crystal layer 109, electric charges of reverse polarity accumulate, resulting in an applied voltage to the liquid crystal layer 109. With increase intensity of writing light 20, the voltage on the liquid crystal layer 109 increases. The state of polarization of the readout light is varied by the voltage on liquid crystal layer 109, and the state of polarization of reflected readout light 23 is shifted accordingly and outputted.
During the resetting period, a positive voltage, with respect to ITO electrode 110, is applied to ITO electrode 102. Namely, the a-Si photodiode 103 is forward biased and the electric charges accumulated during the writing period are withdrawn all at once. This way, when the voltage applied to the ITO electrodes 110 and 102 is opposite in polarity to that of writing period, the electric charges accumulated in reflection layer 107 are removed, resulting in no voltage on the liquid crystal layer 109. As the result, during the resetting period a situation is restored where the reflected readout light 23 is maintained in the same state of polarization as the incoming readout light 22.
Each of the small pieces of the aluminum light reflection layer 107, split by the lattice form insulation layer 108, makes an individual pixel. The lattice form carbon insulation layer 108 electrically insulates so electric charges stored in one of the small pieces of aluminum reflection layer 107 during the writing period do not move to a neighboring small piece.
FIG. 11 is an illustration of a conventional video display device comprising the above described spacial light modulator 1. In FIG. 11, numeral 1 denotes a spacial light modulator, 2 is a reset pulse generating circuit for supplying a reset pulse to the spacial light modulator 1, 3 is a writing video light generating apparatus in which a CRT is normally used and comprised of a CRT 9 and a CRT driving circuit 10. Numeral 4 denotes a writing lens for focusing an image outputted from CRT 9 on the writing light incoming surface of the spacial light modulator 1; 5 is a beam splitter for reflecting or transmitting the light depending on the difference in the state of polarization, which reflects the S wave and transmits the P wave; 6 is a light source of the incoming readout light 22, which is normally a xenon lamp or a metal halide lamp; and 7 is a projection lens for focusing the reflected readout light 23 on a screen 8 as a picture.
The following describes the operation of a video display device constituted as shown in FIG. 11. A video signal generated in the writing video light generating apparatus 3 is outputted from CRT 9 as a writing light 20 to be irradiated on the writing side of spacial light modulator 1 through writing lens 4. Writing light 20 irradiated on spacial light modulator 1 makes each of the pixels accumulate electric charges corresponding to the intensity distribution of the light irradiated on the incoming surface.
A light of random polarity 21 is generated from light source 6. As beam splitter 5 reflects the S wave and transmits the P wave, only the S wave reflected by beam splitter 5 is supplied to spacial light modulator 1 as incoming readout light 22. The incoming readout light 22 supplied to the spacial light modulator 1 is reflected within the spacial light modulator 1 to become reflected readout light 23, during which procedure the state of polarization of the reflected readout light 23 is varied by the electric charges stored in the spacial light modulator 1. The stronger the writing light 20 supplied to the spacial light modulator 1, the higher the voltage applied to the liquid crystal layer 109, resulting in the reflected readout light 23 changing state from the S wave to P wave. The resulting voltage applied to the liquid crystal layer 109 is negative on the writing side with respect to the reading side. As beam splitter 5 allows only the P wave to pass through, the element of P wave alone contained in reflected readout light 23 goes through beam splitter 5 to be focused on screen 8 by projection lens 7.
The state of polarization of reflected readout light 23 varies depending on the quantity of electric charges accumulated in the spacial light modulator 1; when the intensity of writing light 20 is high, an image projected on screen 8 is bright, while it is dark when the intensity is low. Since the image information supplied to the spacial light modulator 1 by the writing light 20 is different in each of the respective pixels, the respective pixels have different electric charges; therefore the state of polarization of reflected readout light 23 varies in each of the respective pixels and an image is projected on screen 8 in accordance with the image information supplied.
The following is a description of the resetting pulse. In FIG. 12(a), a typical resetting pulse 80 is shown. The voltages indicated in FIG. 12(a) are applied between ITO electrode 102 on the writing light side and the ITO electrode 110 on the readout side. A voltage of -3.5V is applied during the writing period and a voltage of +15V is applied during the resetting period. The wave form is rectangular, and the resetting period duration is 300 μs, the duration being unrelated to the vertical synchronization frequency. The form of resetting pulse has three parameters; they are, the width of the resetting pulse, the resetting voltage (a voltage to be applied during resetting period between two ITO electrodes, 102 and 110, of spacial light modulator 1) and the writing voltage (a voltage to be applied during writing period between two ITO electrodes, 102 and 110, of spacial light modulator 1). When the resetting pulse width increases, a picture projected on the screen gets darker, and the higher resetting voltage results in the lower brightness of the picture. Meanwhile, the higher the absolute value of writing voltage the brighter the picture.
Video display devices comprising the above described spacial light modulator 1 are attracting an interest because of a significantly brighter picture over that by transmission type liquid crystal projectors. However, conventional video display devices comprising spacial light modulators, have several problems as described below.
In conventional video display devices comprising spacial image modulators, the resetting period does not coincide with the vertical blanking period,., Accordingly the resetting pulse shown in FIG. 12(a) does not basically overlap with the vertical blanking period, as shown in FIG. 12(b). Resettings are repeated while a picture is being projected. Therefore, in a case where the resetting cycle is relatively closer to the vertical blanking cycle the projected picture has a disturbance by a black belt. In a case where the resetting cycle is shorter than the vertical blanking cycle, the picture suffers from a beat disturbance. Further, because a projected picture gets dark during the resetting period, it was impossible to maximize the time aperture ratio, which resulted in a reduced brightness of the projected picture. This is the first problem.
The above described time aperture ratio is defined by the integration of the light intensity values; where a state in which the highest intensity light is constantly maintained is equal to 100% time aperture ratio. In observing a practical video signal in terms of the brightness from a point in an observation space, even if the brightness is significantly varied within a small fraction of time, the brightness visually perceivable is an integration of the brightness values during the fraction of time, because the speed of compliance by the human eyes is about 1/60 sec. In conclusion, the time aperture ratio is a unit to represent relative brightness; and the higher the value the brighter the picture.
When various images having different vertical synchronization frequencies are to be projected, a balanced timing between resetting and writing is ruined by the vertical synchronization signals, because the resetting period is fixed. When the resetting period goes long, a picture projected on screen gets dark. A second problem stems from the vertical synchronization frequency: because the brightness of a picture on the screen is determined by the relative time ratio between the resetting period and the writing period, if the vertical synchronization frequency is high, the time ratio of the resetting period goes relatively high, resulting in a reduced time aperture ratio, consequently a darker picture.
Further, among various systems comprising spacial light modulators, it is normal to have system to system spreads in the light output. This is mainly caused first by spread in the voltage to be applied to liquid crystal layer 109 of the spacial light modulator 1. This is because there is a spread in the quantity of electrons to be produced by the writing light in an a-Si photodiode layer 103 of a spacial light modulator, and because the resistance value itself of each of the constituent parts of a spacial light modulator 1 has a spread. A second factor of the spread in the light output lies in a fact that even if a same voltage is applied to the liquid crystal layer 109 of the spacial light modulator 1, different light outputs are produced from each respective spacial light modulator 1 because the aligning directions of liquid crystals subtly differ among respective spacial light modulators 1.
In order to absorb the spreads in light output among respective spacial light modulators 1, conventional video display devices comprise an adjusting means within the writing video light generating apparatus 3 for adjusting intensity of the light for writing video information on the spacial light modulator 1. In a case where the writing video light generating apparatus 3 is comprised of CRT 9 and CRT driving circuit 10, the voltage to be applied to the cathode electrode or grid electrode of the CRT 9 is adjusted in the CRT driving circuit 10. Especially when displaying a color image using three pieces of spacial light modulator 1, this adjustment of light output is essential to solve the spreads in light output of the R, G and B colors; otherwise color temperature of the white is affected.
In conventional video display devices comprising spacial light modulators, the above described method of compensating the spreads in light output of the spacial light modulator 1 through the CRT driving circuit 10 created another cause of inconvenience. Because of spreads in the characteristics of the spacial light modulator 1 and peripheral constituent members, the aligning axis of the liquid crystal is sometimes displaced, or insufficient voltage is applied to the liquid crystal layer 109, which results in a situation where the liquid crystal is not completely aligned for the intentional display of total black, allowing some of the light to reach the screen. Where there is a displacement in the revolution angle of the liquid crystal itself, it may not be possible to completely compensate through the adjustment of the intensity of the writing light alone. For the same reason, where there is a shift in the γ curve of the liquid crystal itself, it may not be possible to completely compensate through the adjustment of the intensity of the writing light alone. If unable to display the total black and the total white, the contrast of the projected picture is affected and the quality of picture deteriorates. These inconveniences that have arisen as a result of the adjustment of the light intensity for compensating the spread in light output are of a nature which is not solvable through the adjustment of the intensity of light for writing on spacial light modulator 1.
As described above, conventional video display devices comprising spacial light modulators have a third problem that stems from the spread in characteristics of the spacial light modulator itself.
SUMMARY OF THE INVENTION
Various problems as described above are solved by the present invention. The degradation of picture quality due to disturbances like a dark belt and beat hazard in the picture, occurring as a result of the application of the resetting pulse, are removed. The decreased brightness that stems from the vertical synchronization frequency is solved, and the decreased contrast due to the inability to display complete black or complete white is improved. Thus the present invention intends to prevent deterioration of the quality of picture displayed.
A video display device, according to a first embodiment of the present invention, comprises
a light writing type spacial light modulator,
a writing video light generating apparatus for generating a light scanning horizontally and vertically for writing in said spacial light modulator, and
a vertical synchronization reset pulse generating circuit for generating a reset pulse synchronized with a vertical synchronization signal of said writing video light generating apparatus for withdrawing electric charges produced by the incoming writing light and accumulated in said spacial light modulator, to be applied between the first and second electrodes of said spacial light modulator.
The reset pulse generator of a video display device, according to the first embodiment, generates a resetting pulse only once for each vertical blanking period.
A video display device, according to a second embodiment of the present invention, comprises
a light writing type spacial light modulator,
a writing video light generating apparatus for generating a light scanning horizontally and vertically for writing in said spacial light modulator,
a vertical synchronization reset pulse generating circuit for generating a reset pulse synchronized with a vertical synchronization signal of said writing video light generating apparatus for withdrawing electric charges produced by the incoming of said writing light and accumulated in said spacial light modulator, to be applied between the first and second electrodes of said spacial light modulator,
a frequency/voltage converting circuit for converting the frequency of said vertical synchronization signal to a voltage in accordance with the frequency value, and
a reset pulse controlling circuit for modulating the pulse width of said resetting pulse, the resetting voltage to be applied between the two electrodes of said spacial light modulator during the resetting period and the writing voltage to be applied between the two electrodes of said spacial light modulator during a writing period in accordance with the output of said frequency/voltage converting circuit.
A video display device, according to a third embodiment of the present invention, comprises
a light writing type spacial light modulator,
a writing video light generating apparatus for generating a light scanning horizontally and vertically for writing in said spacial light modulator,
a reset pulse generating circuit for generating a reset pulse for withdrawing electric charges produced by the incoming of said writing light and accumulated in said spacial light modulator, to be applied between the first and second electrodes of said spacial light modulator, and
a reset pulse voltage adjusting circuit for varying the writing voltage to be applied between the two electrodes of the spacial light modulator during the writing period and the reset voltage to be applied between the two electrodes of the spacial light modulator during a resetting period.
The reset pulse voltage adjusting circuit of the third embodiment of the present invention comprises
a voltage generator for generating the writing voltage to be applied between the two electrodes of the spacial light modulator during the writing period and the reset voltage to be applied between the two electrodes of the spacial light modulator during the resetting period,
a voltage controller for controlling the voltage to be outputted from said voltage generator, and
a memory circuit for memorizing said voltage value.
In the first embodiment, resetting is performed within the vertical blanking period. Consequently, picture disturbances like black belt or beat hazard that appeared in a prior art devices when a resetting pulse was applied to a spacial light modulator, do not come in sight; and the time aperture ratio can be maximized.
In the second embodiment, time balance between the resetting and the writing can be adjusted for a varied vertical synchronization frequency, by varying the reset pulse voltage and the reset pulse width in accordance with the vertical synchronization frequency. Therefore, the brightness of the picture is maintained constant without degrading the time aperture ratio.
In the third embodiment, voltage to be applied to the liquid crystal layer of the spacial light modulator can be adjusted for the varying light output of the spacial light modulator by adjusting the resetting voltage and the writing voltage to be applied between the two electrodes of the spacial light modulator. The resetting voltage and the writing voltage are adjusted by the reset pulse controlling circuit, comprised in the embodiment, which varies the writing voltage to be applied between the two electrodes of the spacial light modulator during the writing period and the resetting voltage to be applied between the two electrodes of the spacial light modulator during the resetting period. Consequently, the displacements in aligning axis and γ characteristics of the liquid crystal of the spacial light modulator, compensation of which was impossible by adjustment of the light intensity of the writing light to the spacial light modulator, are compensated and display of the complete black and the complete white becomes possible.
The reset pulse controlling circuit of the third embodiment allows easy adjustment of the writing voltage to be applied to the two electrodes of the spacial light modulator during the writing period and the resetting voltage to be applied to the two electrodes of the spacial light modulator during the resetting period.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a video display device according to the first embodiment of the present invention.
FIGS. 2A and 2B are waveform charts showing the relationship between the resetting pulse and the vertical blanking.
FIG. 3 shows a practical example of a reset pulse generating circuit.
FIG. 4 is a diagram illustrating a video display device according to the second embodiment of the present invention.
FIG. 5 shows a practical example of a frequency/voltage converting circuit and a reset pulse controlling circuit.
FIG. 6 is a diagram illustrating a video display device according to the third embodiment of the present invention.
FIG. 7 shows an example of a functional diagram of a reset pulse voltage adjusting circuit and a reset pulse voltage generating circuit.
FIG. 8 shows an equivalent circuit of a spacial light modulator.
FIGS. 9A-1, 9A-2, 9A-3, 9B-1, 9B-2, 9B-3, 9C-1, 9C-2 and 9C-3 are all diagrams which are useful for explaining the voltage adjustment of the spacial light modulator.
FIG. 10 shows the structure of a spacial light modulator.
FIG. 11 is a diagram illustrating a prior art video display device.
FIGS. 12A and 12B are waveform charts showing the conventional relationship between the resetting pulse and the vertical blanking.
DESCRIPTION OF THE PREFERRED EMBODIMENT
(First Embodiment)
FIG. 1 shows a video display device according to the first embodiment of the present invention. In FIG. 1 numeral 1 denotes a spacial light modulator, 2a a reset pulse generating circuit, 3 a writing video light generating apparatus comprised of, in this embodiment, a CRT 9 and a CRT driving circuit 10a. Numeral 4 denotes a writing lens for having a video light outputted from the writing video light generating apparatus 3 focused on the spacial light modulator 1, 5 a beam splitter for reflecting or transmitting a light depending on the state of polarization, reflecting the S wave and transmitting the P wave. Numeral 6 denotes a light source of readout light, e.g. a xenon lamp. Numeral 7 denotes a projection lens which projects an image on a screen 8. The constitution and functioning of spacial light modulator 1 have already been described above, therefore such explanation is omitted here.
Although operation of the basic part of the video display device shown in FIG. 1 remains the same as that of a prior art video display device shown in FIG. 11, a description is repeated here for ease of comprehension. In FIG. 1, a video signal generated in the writing video signal generating apparatus 3 is outputted from CRT 9 as a writing light 20 to be irradiated on the incoming side of spacial light modulator 1 through the writing lens 4. The writing light 20, irradiated on the spacial light modulator 1, makes each of the pixels accumulate electric charges corresponding to the intensity distribution of the light irradiated on the incoming surface.
A light of random polarity 21 is generated from the light source 6. As the beam splitter 5 reflects the S wave and transmits the P wave, only the S wave reflected by the beam splitter 5 is supplied to the spacial light modulator 1 as incoming readout light 22. The incoming readout light 22 supplied to the spacial light modulator 1 is reflected within the spacial light modulator 1 to become reflected readout light 23, a procedure during which the state of polarization of reflected readout light 23 is varied by the electric charges stored in the spacial light modulator 1. When a writing light 20 is supplied on spacial light modulator 1, the reflected readout light 23 changes its state from the S wave to P wave. As beam splitter 5 allows only the P wave to pass through, elements of P wave alone contained in the reflected readout light 23 go through the beam splitter 5 to be focused on the screen 8 by the projection lens 7.
The state of polarization of reflected readout light 23 varies depending on the quantity of electric charge accumulated in the spacial light modulator 1; when the intensity of the writing light 20 is high a picture projected on the screen 8 is bright, while it is dark when the intensity is low. Image information supplied on the spacial light modulator 1 differs in each of the respective pixels, and each of the pixels is provided with different electric charges of its own; therefore the state of polarization of the reflected readout light 23 varies depending on respective pixels and a picture is projected on the screen 8 in accordance with the image information supplied.
The electric charges accumulated during a writing period within the spacial light modulator 1 by the writing light 20 are withdrawn by applying a resetting pulse between two ITO electrodes of the spacial light modulator 1. In this first embodiment, a synchronization signal 11 outputted from the CRT driving circuit 10a of the writing video light generating apparatus 3 is outputted to the reset pulse generating circuit 2a. As a result, the resetting pulse is synchronized with the vertical synchronization signal 11, and applied between the two ITO electrodes of the spacial light modulator 1. As the resetting pulse is arranged to occur only once during the vertical blanking period of the writing video light generating apparatus 3, the black belt which appeared in a conventional picture due to the resetting pulse comes up during the vertical blanking period in this embodiment; so it does not appear in a picture.
FIG. 2(a) shows a typical voltage waveform of a reset pulse 30 according to this embodiment. The voltage of the reset pulse 30 in FIG. 2(a) is indicated with readout side ITO electrode 110 of spacial light modulator 1 shown in FIG. 10 as the base potential. The voltage is a square wave of -3.5V during the writing period, and +15V during the resetting period. Duration of the resetting period is 300 μsec., and the reset pulse occurs within the vertical blanking period as described earlier. FIG. 2(b) shows the timing of control on vertical blanking, indicating that the resetting period in FIG. 2(a) is included within the vertical blanking period of FIG. 2(b).
According to the first embodiment of the present invention, the black belt, which conventionally appeared due to the reset pulse in a picture, occurs within a vertical blanking period, therefore never appears in a picture. Further, the time aperture ratio can be set to the highest possible extent. Thus a quality picture of high brightness is made available.
A practical example of a reset pulse generating circuit 2a is shown in FIG. 3. A resetting voltage generating circuit 31 generates a resetting voltage to be applied between the two electrodes of the spacial light modulator 1 during the resetting period. A writing voltage generating circuit 32 generates a writing voltage to be applied between the two electrodes of the spacial light modulator 1 during the writing period. In the resetting voltage generating circuit 31 and writing voltage generating circuit 32 of the present embodiment, any desired voltages are produced through a simple voltage dividing circuit comprised of resistors. A pulse width controlling circuit 33 detects the rising of vertical synchronization signal 11, and converts it into a negative polarity pulse having specific pulse width. The pulse width controlling circuit 33 of the present embodiment comprises a general-use mono-stable multi vibrator IC. Numeral 34 denotes an emitter-grounded transistor for reversal, 35 is a collector resistor of transistor 34. A pulse of negative polarity outputted from the pulse width controlling circuit 33 is applied to the base of transistor 34. As a result, a positive polarity pulse is generated in the collector of transistor 34 with the resetting voltage at the HIGH side and writing voltage at the LOW side. The positive polarity pulse is inputted to an output amplifier 36, current of which is amplified to be applied between the two electrodes of the spacial light modulator 1 as reset pulse 37. Since the reset pulse generating circuit 2a is triggered by the vertical synchronization signal 11, a resetting pulse having a desired pulse width is obtainable in synchronization with the vertical synchronization signal 11.
The foregoing descriptions have been made assuming a single color light. For displaying a picture in color using the present system, three sets of spacial light modulator 1, writing video light generating apparatus 3, writing lens 4, beam splitter 5 and projection lens 7 are necessary, each corresponding to the three primary colors, R, G and B, respectively. In addition, a dichroic mirror is needed to split light from light source 6 into the three primary colors, R, G and B. The functions as revealed in the present embodiment also produce the same effects in a color display system.
(Second embodiment)
FIG. 4 shows the structure of a video display device according to the second embodiment of the present invention. In FIG. 4, numeral 1 denotes a spacial light modulator, 2b a reset pulse generating circuit for driving the spacial light modulator 1, 3 a writing video light generating apparatus which is comprised of a CRT 9 and a CRT driving circuit 10b in this embodiment. Numeral 4 denotes a writing lens for focusing an image outputted from the writing video light generating apparatus 3 on the spacial light modulator 1. Numeral 5 denotes a beam splitter for reflecting or transmitting a light depending on the state of polarization, it reflects the S wave and transmits the P wave. Numeral 6 denotes a readout light source, e.g., a xenon lamp. A projection lens 7 projects a focused image on a screen 8. In the second embodiment, the above described constituent sections operate in the same manner as those of the first embodiment, and the structure and function of spacial light modulator 1 have already been described, therefore these are not repeated here.
In the following, description is made only on the points which differ from the first embodiment. In FIG. 4 numeral 13 denotes a frequency/voltage converting circuit (hereinafter, FV converting circuit), 14 denotes a reset pulse controlling circuit for controlling the form of the reset pulse with the vertical synchronization signal as trigger. The reset pulse controlling circuit 14 in the present embodiment maintains a fixed ratio between the resetting period and the writing period regardless of the frequency of the vertical synchronization signal.
FIG. 5 shows a practical example of the FV converting circuit 13 and the reset pulse controlling circuit 14. When the vertical synchronization signal 11 is inputted, the FV converting circuit 13 generates a voltage corresponding to the frequency of the vertical synchronization signal 11. In a circuit of the present embodiment, the output voltage from the FV converting circuit 13 decreases with an increasing vertical synchronous signal 11 frequency. Practically, in the FV converting circuit 13, the vertical synchronization signal 11 is inputted to a mono-stable multi vibrator 41. The mono-stable multi vibrator 41 generates a negative polarity pulse of a certain width determined by the values of resistor 42 and capacitor 43. The negative polarity pulse is then supplied to an integrating circuit 44 to be integrated there and converted into a direct current voltage. As the input to the integrating circuit 44 is a pulse of negative polarity, the output of the FV converting circuit 13 decreases with an increasing frequency of the vertical synchronization signal 11.
In the reset pulse controlling circuit 14, a pulse is generated by a mono-stable multi vibrator 47. The output voltage of the FV converting circuit 13 is supplied to the base of a transistor 46, and causes the flow of electric current through the emitter resistor 45. As described earlier, when the frequency of the vertical synchronization signal 11 increases, the output voltage of the FV converting circuit 13 decreases, resulting in an increase of electric current flow through the emitter resistor 45, and the capacitor 48 is charged within a short period of time. As a result, the pulse width of the output pulse from the mono-stable multi vibrator 47 decreases. On the contrary, when the frequency of the vertical synchronization signal 11 decreases, the pulse width of the output pulse from the mono-stable multi vibrator 47 increases. Therefore, by setting the constant of the emitter resistor 45 and the capacitor 48 at an appropriate value, the time ratio of the output pulse of the mono-stable multi vibrator 47 to the vertical interval may be fixed. As the output pulse of the mono-stable multi vibrator 47 is triggered by the vertical synchronization pulse 11, an output pulse having a fixed pulse width time ratio, and synchronized with the vertical synchronization frequency, is supplied to the reset pulse generating circuit 2b.
As described above, by controlling the reset pulse width in accordance with the frequency of the vertical synchronous signal, it becomes possible to solve the problems stemming from the vertical synchronization frequency. The time balance of resetting and writing is broken by the vertical synchronization signal, and as the vertical synchronization frequency increases, the time aperture ratio decreases, rendering a dark picture.
In the second embodiment described above, the reset pulse width has been controlled in accordance with the vertical synchronization frequency. When the reset pulse width is increased, a picture projected on screen 8 gets dark. In addition to the width of the reset pulse, parameters for shaping of the resetting pulse include the reset voltage to apply between the two electrodes of the spacial light modulator 1 during the resetting period and the writing voltage to be applied between the two electrodes of the spacial light modulator 1 during the writing period. There exists a relationship that a higher reset voltage results in a darker image output, and the higher the absolute value of the writing voltage the brighter the image output. Consequently, shifting of any of said three parameters results in the same effect of controlling the brightness of a picture.
For example, when the vertical synchronization frequency increases, the balance between the resetting and the writing is broken and image output darkens. This can be compensated by decreasing the resetting voltage. However, in a case where the reset pulse width is kept fixed, if the vertical frequency increases the resetting pulse can not be provided within the vertical blanking period. This results in an overlapping of the resetting pulse and the image signal which is projected dark on a screen. In order to avoid occurrence of such deterioration of picture quality, the reset pulse controlling circuit 14 in the second embodiment of the present invention controls the width of the reset pulse in accordance with the vertical synchronization frequency.
In the reset pulse controlling circuit, it is easy to modulate the reset voltage and the writing voltage, which are applied between the two electrodes of the spacial light modulator 1 during the resetting period and writing period respectively, by the output of FV converting circuit 13. Practically, when vertical synchronization frequency increases, the output voltage from the FV converting circuit 13 decreases. Therefore, by modulating the reset voltage with the output voltage from the FV converting circuit 13 using an operational amplifier or other means, the reset voltage may be decreased when the vertical synchronization frequency increases, and a picture projected on screen can be maintained as brighter as compared with that without modulating the reset voltage. Also, the phenomenon where a projected picture turns dark when the vertical frequency increases can be compensated. Similarly, by modulating the writing voltage with the output voltage from FV converting circuit 13, the writing voltage may be decreased (the absolute value increases) when the vertical synchronization frequency increases, and the brightness of the projected picture can be maintained at a constant level.
As described above, by modulating the reset voltage and the writing voltage, not only the reset pulse width, with the vertical synchronization frequency the brightness of video output can be maintained constant against varied vertical synchronous frequency when projecting various pictures of different vertical synchronization frequencies. In addition, the reset pulse can be disposed within the vertical blanking period even when the vertical frequency is high; thus, the reset pulse and the video signal never supersede each other, so the degradation of picture quality caused by an overlapping of the reset pulse and the video signal projected on a screen as a black belt is prevented.
The foregoing descriptions have been made assuming a single color light. For displaying a picture in full-color using the present system, three sets of spacial light modulator 1, writing video light generating apparatus 3, writing lens 4, beam splitter 5 and projection lens 7 are necessary, each corresponding to the three primary colors, R, G and B, respectively. In addition, a dichroic mirror is needed to split light from a light source 6 into the three primary colors, R, G and B. The functions as revealed in the present embodiment also produce the same effects in a full-color display system.
(Third Embodiment)
FIG. 6 shows a constitution of a video display device according to a third embodiment of the present invention. Many of the constituent parts in FIG. 6 are in common with those in FIG. 1 where the constitution of the first embodiment is shown. Therefore, the following only describes those which are different from FIG. 1. In FIG. 6, numeral 2c denotes a reset pulse generating circuit, which generates a reset pulse controlled by the output from a reset pulse voltage adjusting circuit 15. The reset pulse voltage adjusting circuit 15 adjusts the writing voltage to be applied between the two electrodes of the spacial light modulator 1 during the writing period and the resetting voltage to be applied between the two electrodes of spacial light modulator 1, during the resetting period. The other constituent parts and their functions are the same as those described in the first embodiment shown in FIG. 1. and the structure and function of spacial light modulator 1 have already been described, therefore these are not repeated here.
A practical example of reset pulse voltage adjusting circuit 15 is shown in FIG. 7. Numeral 51, normally comprised of a D/A converter (DAC), denotes a voltage generator for supplying the reset pulse generating circuit 2c the writing voltage to be applied between the two electrodes of the spacial light modulator 1 during the writing period and the resetting voltage to be applied between the two electrodes of the spacial light modulator 1 during resetting period. Numeral 52, normally comprised of a microcomputer, denotes a voltage controller for controlling voltage generator 51 by providing to voltage generator 51, information on voltage to be outputted. A memory 53, normally comprised of an EEP-ROM, stores values of voltages to be outputted by the voltage generator 51, or the resetting voltage value and the writing voltage value.
Numeral 2c denotes a reset pulse generating circuit. The basic function of reset pulse generating circuit remains the same as that described in the first embodiment; however, the constitution in the present embodiment differs from that of reset pulse generating circuit 2a of the first embodiment shown in FIG. 1. In the reset pulse generating circuit 2c of the present embodiment, as the resetting voltage and the writing voltage are supplied by the reset pulse voltage adjusting circuit 15, the resetting voltage generating circuit 31 and the writing voltage generating circuit 32 in FIG. 3 are replaced respectively by the current amplifier for resetting voltage 54 and the current amplifier for writing voltage 55.
In adjusting the resetting voltage and the writing voltage using the reset pulse voltage adjusting circuit 15, when an instruction to control the voltage is given from outside through e.g. a remote controller, the voltage controller 52 issues an instruction to the voltage generator 51 to change the voltage. Upon receiving an instruction to memorize information, or to turn power supply to the system OFF, the voltage controller 52 orders memory 53 to store the information on voltage being supplied to the voltage generator 51. When power supply to the system is turned ON, the voltage controller 52 reads the voltage information stored in memory 53, which information is then communicated to voltage generator 52 to control voltage generator 51.
The voltage waveform of a typical reset pulse outputted from the reset pulse generating circuit 2c is as shown earlier in FIG. 2(a), in which the ITO electrode 110 in readout side of spacial light modulator 1 in FIG. 10 is used as the base potential. The voltage has a rectangular waveform and is 3.5V during writing period, and is +15V during the resetting period. The time ratio between the writing period and the resetting period is 60:1.
The following describes how contrast is compensated through adjustments of the reset voltage to be applied between the two electrodes of the spacial light modulator 1 during the resetting period and the writing voltage to be applied between the two electrodes of the spacial light modulator 1 during the writing period.
FIG. 8 is an equivalent circuit of a spacial light modulator 1, where numeral 61 denotes a diode component of an a-Si photodiode 103, 62 an equivalent capacitance (capacitor) component of an a-Si photodiode 103, 63 an equivalent resistance component of an a-Si photodiode 103, 64 an equivalent capacitance (capacitor) component of a liquid crystal layer 109, 65 an equivalent resistance component of a liquid crystal layer 109. Operation of the equivalent circuit is as described earlier: The electrons excited by the writing light during the writing period accumulate between capacitor Ca 62 and capacitor Cc 64, and are withdrawn by a forward biased diode D 61 when the reset voltage is applied during the resetting period; this cycle is repeated. The revolving angle of the liquid crystal is determined by a voltage applied between the both ends of capacitance Cc 64, and controls the intensity of light to be supplied as the output of video display system. Practically, for the white display the brightness increases along with the increasing absolute value of negative voltage applied to capacitor Cc 64, with the readout side as the basis. There is of course a saturating value in the voltage. For the black display, the darkness increases along with the increasing absolute value of positive voltage to be applied to both ends of capacitor Cc 64. Namely, the higher the absolute value of voltage to capacitor Cc 64 the greater the contrast.
The voltage on capacitor Cc 64 is influenced by equivalent resistances Ra 63, and Rc 65 within the spacial light modulator 1, and by other elements including for example the resistance values of the ITO electrodes 102, 110, the resistance value of connecting wire between spacial light modulator 1 and the reset pulse generating circuit 2c, and the resistance values of connectors. In FIG. 8, the values of resistances caused by such elements other than the equivalent resistances Ra 63, and Rc 65 within the spacial light modulator 1, are collectively represented as a resistor R 66. The existence of resistor R 66 means that the voltage to be applied to the liquid crystal layer 109 is influenced by not only the spreads in equivalent resistances Ra 63, and Rc 65 but also by resistor R 66; consequently the resetting voltage and the writing voltage to be applied to the spacial light modulator 1 have to take the voltage reduction due to resistor R 66 into consideration. Therefore, in making compensation of the contrast, the voltage to be applied to the liquid crystal layer 106 needs to be controlled considering the spreads in values of these equivalent resistances and the voltage reduction due to resistor R 66.
FIGS. 9A-1, 9A-2, 9A-3, 9B-1, 9B-2, 9B-3, 9C-1, 9C-2 and 9C-3 are all diagrams which are useful for explaining the principle of contrast compensation from the view point of revolution angle of liquid crystal. The description is based on an assumption that the material used in the spacial light modulator 1 is a ferroelectric liquid crystal material. FIGS. 9A-1, 9A-2 and 9A-3 illustrates a case where an appropriate voltage is applied to the liquid crystal layer 109; in FIG. 9A-1 numeral 71 represents a state of liquid crystal in black display, 72 in FIG. 9A-2 represents a state of liquid crystal in white display. When, the revolving angle of the liquid crystal reaches maximum, the γ curve takes a shape of curve 73 in(c). FIGS. 9B-1, 9B-2 and 9B-3 illustrate a situation where there is insufficient voltage applied to the liquid crystal layer 109; in black display the liquid crystal is in a position 74 of FIG. 9B-1 which is slightly revolved clockwise, while in white display the liquid crystal is revolved to a certain angle shown as 75 in FIG. 9B-2, which angle is smaller than that at a normal white display 72. The γ curve at this situation is represented as curve 76 shown in FIG. 9B-3; there is some output of reflected light even when there is no input of writing light, whereas even when the writing light is at its highest, the output is lower than γ curve 73 representing the normal situation, which means that it provides only a weak reflected light. In order to compensate the situation of diluted black as illustrated in FIG. 9B-1, the resetting voltage is increased and the liquid crystal in black display revolves counter-clockwise to 77 in FIG. 9C-1 to resume normal black display. In order to compensate for the situation of darkened white as illustrated in FIG. 9B-2, the writing voltage is decreased (larger absolute value) and the liquid crystal in white display revolves clockwise to 78 in FIG. 9C-2 to resume normal white display. This compensation results in the γ curve being restored to the normal curve 73, as illustrated as curve 79 FIG. 9C-3.
As described above, the black display and the white display may be compensated by increasing the resetting voltage against the diluted black, and decreasing the writing voltage against the darkened white. Therefore, by adjusting the resetting voltage and the writing voltage respectively, spreads in the characteristics of the spacial light modulator 1 may be compensated, providing always an appropriate contrast and γ characteristic. The adjusting of resetting voltage and that of writing voltage are not necessarily linked together.
For displaying a picture in full-color using the present system, three sets of spacial light modulator 1, writing video light generating apparatus 3, writing lens 4, beam splitter 5 and projection lens 7 are necessary, each corresponding to the three primary colors, R, G and B, respectively. In addition, a dichroic mirror is needed to split light from a light source 6 into the three primary colors, R, G and B. The functions as revealed in the present embodiment also produce the same effects in a full-color display system.
Further, in such full-color display systems, the present invention not only compensates spreads in the characteristics of the spacial light modulator but it also enables the white balancing of RGB, making it possible to produce with ease an appropriate color temperature of white. In addition, as the resetting voltage and the writing voltage each corresponding to the three RGB primary colors can be established independently, the present invention makes it possible to produce a video output of any desired color temperature by adjusting the balance of light emission among the three RGB primary colors. | In a projection type video display device comprising a light writing type spacial light modulator, disturbances brought about by a resetting pulse and appearing in a projected picture as a black belt or beat are prevented. This is accomplished by causing the resetting pulse, which is to withdraw electric charges produced by incoming writing light and accumulated in spacial light modulator, to occur within a vertical blanking period synchronized with vertical synchronization signal.
Further, by changing the pulse width and the voltage of the resetting pulse in accordance with vertical synchronization frequency, pictures of a certain fixed brightness are made available against various vertical synchronization frequencies; and even with a high vertical synchronization frequency, projected pictures are never annoyed by such disturbance that is caused by a resetting pulse dislocated out of the vertical blanking period.
Further, by controlling the adjustments of the writing voltage to be applied to the spacial light modulator during the writing period and the resetting voltage to be applied to the spacial light modulator during the resetting period, the spread in characteristics of the spacial light modulator is compensated to provide a certain fixed contrast and γ characteristic. Furthermore, in a video display device for full-color display, writing voltage and resetting voltage can be established independently corresponding to the respective three RGB primary colors, video outputs of any desired color temperature are obtainable by adjusting the balance of light emission among the three RGB colors. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a lens-fitted photographic film package, and more particularly to a photographic film package which has a photographic film, a taking lens, a film transporting means, an exposure means and their associated elements incorporated in a light-tight film case as an integral whole.
A lens-fitted photographic film package can provide many chances to enjoy oneself by easily taking pictures even without a camera. This lens-fitted photographic film package comprises a light-tight film case with a taking lens fitted thereto, a simple exposure mechanism which includes a film transporting mechanism and a shutter mechanism with their associated elements incorporated in the film case, and a 110-size cartridge film or a 35mm full size film previously contained in the light-tight film case, which can be sold wherever photographic film is sold. The lens-fitted photographic film package, after the exposure of all frames of a roll of film, is forwarded to a photo shop or photo laboratory without removing the film. There, the exposed film is removed by breaking open the lens-fitted photographic film package and is developed to make prints therefrom while the empty lens-fitted photographic film package is scrapped. The prints together with the developed film are returned to the customer. The lens-fitted single-use photographic film package makes it easy to take pictures because of no need for film loading and unloading.
For economy, the film case that incorporates a roll of film and the necessary elements all in one is made of plastic materials and configured as simply as possible. The lens-fitted photographic film package is generally divided into three sections, a main body section which is formed with a film patrone-receiving chamber and a film take-up chamber and has mounted thereon a taking lens and a shutter charging mechanism and a film transporting mechanism; a front cover section attached to the main body section to help support the taking lens and to cover various elements attached to or mounted on the main body section, and a back cover section attached to the back side of the main body section to cover light-tightly the patrone-receiving and film take-up chambers. The lens-fitted photographic film package as sold is enclosed in a thin cardboard or plastic external case with an ornamental pattern printed thereon.
A commercial requirement of such a lens-fitted photographic film package is that it be thin and compact. For example, it is preferably pocket size so that it can be easily carried in a pocket or purse.
A recent tendency is to incorporate electronic flash units in such lens-fitted photographic film packages. Incorporating an electronic flash unit can greatly increase the usage of such lens-fitted photographic film packages.
In manufacturing such lens-fitted photographic film packages with electronic flash units incorporated therein, it is necessary to perform a test discharge of the electronic flash unit in advance of loading a roll of film in the lens-fitted photographic film package. Because the electronic flash unit is charged again after the test discharge, the condenser can be accidentally discharged and expose the film during loading of a roll of film in the lens-fitted photographic film package, particularly if the package is of the type in which the unexposed film is not in a film patrone when assembly is completed. Therefore, it is necessary to maintain the condenser of the electronic flash unit discharged during assembly.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a lens-fitted photographic film package which is thin and compact for convenience of carrying.
It is another object of the present invention to provide a lens-fitted photographic film package which enables removing a film from the lens-fitted photographic film package without taking the film out of an external case.
It is still another object of the present invention to provide a lens-fitted photographic film package which has an electronic flash unit incorporated therein.
It is a further object of the present invention to provide a lens-fitted photographic film package in which a condenser of the electronic flash unit can be maintained discharged during assembly of the lens-fitted photographic film package.
SUMMARY OF THE INVENTION
To accomplish the above and other objects, the lens-fitted photographic film package according to the present invention has at least a roll of photographic film, taking lens means, film transporting means and exposure means as an integral whole. These are contained in a light-tight case. The case comprises a main case section mounting the taking lens means and exposure means and film transporting means and containing light-tightly the roll of unexposed photographic film; and a front cover section which is attached to the main case section to cover most of the exposure means and film transporting means and associated elements, the front cover section being formed with at least one opening for partially receiving therein a member of at least one of the means and elements mounted on the main case section projecting beyond a spatial datum plane defined by surfaces of the main case section which are in contact with an inner surface of the front cover section when the front cover section is securely attached to the main case section.
According to a preferred embodiment of the present invention, the openings formed in the front cover section receive therein a film transporting knob of the film transporting means and a member covering a part of the shutter mechanism, such as a shutter biasing spring, of the exposure means.
According to another preferred embodiment of the present invention, the lens-fitted photographic film package has electronic flash means contained in the main case section, a pair of terminals mounted on the main case section and electronically connected to electrodes of a condenser of the electronic flash means, and short circuiting means removably disposed in said case to electrically connect the pair of terminals so as to short-circuit the condenser to discharge it until the roll of photographic film has been loaded in the main case section.
According to still another preferred embodiment of the present invention, the lens-fitted photographic film package is enclosed in an external case formed with an openable portion defined by perforated lines which is located in correspondence with a part of the film-receiving chamber. The openable portion of the external case is broken or torn off to form an opening in the external case, through which the exposed film can be removed.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following detailed description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings in which like parts are designated by like numerals throughout the views of the drawings and wherein:
FIG. 1 is a front view showing a conventional lens-fitted photographic film package;
FIG. 2 is a top view showing the lens-fitted photographic film package of FIG. 1;
FIG. 3 is an exploded perspective view showing a lens-fitted photographic film package according to a preferred embodiment of the present invention;
FIG. 4 is a front view, similar to FIG. 1, showing a front case section of the lens-fitted photographic film package shown in FIG. 3;
FIG. 5 is a front view showing the lens-fitted photographic film package shown in FIG. 3;
FIG. 6 is a top view, similar to FIG. 2, showing the lens-fitted photographic film package shown in FIG. 3;
FIG. 7 is a sectional view showing the structure of an electronic flash unit incorporated in the lens-fitted photographic film package shown in FIG. 3;
FIG. 8 is a perspective view showing an external container in which the lens-fitted photographic film package of FIG. 3 is to be enclosed;
FIG. 9 is a perspective view showing the lens-fitted photographic film package enclosed in the external container with the bottom cover open;
FIG. 10 is a perspective view showing an external container of another preferred embodiment of the present invention; and
FIG. 11 is a perspective view showing a lens-fitted photographic film package with a bottom cover open which is enclosed in the external container shown in FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
Before describing the present invention in detail, reference is made to FIGS. 1 and 2 for the purpose of providing a brief background that will enhance an understanding of the novel structural features of the lens-fitted photographic film package described later. As shown in FIG. 1, the conventional lens-fitted photographic film package has a front cover 1 of which the front wall 2 is formed with several openings such as a lens opening 21 for exposing a taking lens, semi-circular slots 2b enclosing the lens opening 2a for rendering the region of front wall 2 surrounding the lens opening 2a relatively elastic, small openings 2c which are engaged with lugs of a main body section to retain the front cover 1 attached to the main body section, and some holes used for molding the front cover 1. The front cover 1 further has a top wall 3 formed with openings such as an opening 3a for receiving a shutter button 4 and a counter window 3b through which a front counter is viewed.
As is shown in FIG. 2, the main body section has on its front wall a lens holder 5 and a chamber 6 for containing a shutter biasing or charging spring, and on its top wall a film transporting knob 7 which partly protrudes from the case. Indicated by a reference 1a is the inner surface of the front wall 2 of the front cover 1. The lens holder 5 and the spring chamber 6 project from the front wall of the main body section.
As is apparent, the thickness of the package is defined between the external surface of the front wall 2 and the external surface of a rear cover. Because of the provision of the lens holder 5 and the spring chamber 6, the conventional lens-fitted photographic film package is relatively thick.
Referring now to FIGS. 3 to 6, shown therein is a lens-fitted photographic film package (which is hereinafter referred to as a film package for simplicity) of a first preferred embodiment of the present invention. The film package of the present invention comprises a main body section 11, a front cover section 12 and a back cover section 13 which are made of plastic materials and fitted or welded in a well known manner, such as by ultrasonic welding, to form a light-tight box-shaped film container.
The main body section 11 is formed with a film patrone-receiving chamber 14 on the left side and an unexposed film-receiving chamber 15 on the right side. The patrone-receiving chamber 14 receives therein a film patrone or cartridge 16 adapted to contain a roll of photographic film and the unexposed film chamber 15 receives the unexposed photographic film withdrawn from the film patrone 16 and wound up in a roll in chamber 15. The film package of this embodiment has been pre-wound in one direction (left to right in FIG. 3) so that the full length of unexposed film has been wound up into the film take-up chamber 15 before making a first exposure and is rewound by the user from the take-up chamber 15 back into the film patrone 16 in the film patrone-receiving chamber 14 by one frame every exposure.
The main body section 11 is provided with a film rewinding knob 18 rotatably mounted thereon above the film patrone-receiving chamber 14. The film rewinding knob 18 has a film rewinding shaft with a forked end extending into the film patrone-receiving chamber 14 and engaging an external end of a spool 16a of the film patrone 16. The film rewinding knob 18 is formed with teeth on the periphery thereof which are engaged with a ratchet 19 mounted on the main body section 11 for the prevention of rotation thereof in the wrong direction.
An exposure chamber 20 is provided between the film patrone-receiving chamber 14 and the film take-up chamber 15 and is formed with an exposure opening 21 in the front wall thereof. A lens holder plate 30 with a lens mount 31 is attached to the front wall of the exposure chamber 20. A taking lens or lens assembly 32 having a fixed focal length is held by the lens mount 31. The lens holder plate 30 is integrally formed with a rectangular projecting cap 33 forming therebehind a space for receiving therein a spring 23. The lens holder plate 30 is attached to section by engaging hooks 34 engageable with detents 28 formed integrally with the main body section 11.
Between the front wall of the exposure chamber 20 and the lens holder plate 30, there is a shutter blade 22 mounted on the front wall of the exposure chamber 20 for rotation about an axis parallel to the optical axis of the taking lens 32. The shutter blade 22 is biased by the spring 23 to turn in the counterclockwise direction as viewed in FIG. 1 so as to close the exposure opening 21. The shutter blade 22 is formed with an upstanding projection. A shutter charge lever 24 can move to push this projection of the shutter blade 22 so as to turn the shutter blade 22 to open the exposure opening 21 and to charge the biasing spring 23.
A sprocket wheel (not shown) with sprocket teeth, which is well known in the art, is provided behind and close to the film take-up chamber 15 to engage in perforations 17a of film 17 so as to be rotated by the advance of film 17. A one-frame metering cam (not shown) is driven by that sprocket wheel to swing the shutter charge lever 24. Upon such movement of the shutter charge lever 24, a hook lever 25 is turned and is brought into engagement with the film rewinding knob 18, stopping the rotation of the film rewinding knob 18. Such a mechanism is well known in the photographic art as a self-cocking mechanism, and therefore a more detailed description need not be given herein. The sprocket wheel has a shaft 26 with an axially extending V-shaped groove which is engageable with teeth formed on the periphery of a frame or exposure counter disk 27. Through this engagement, the exposure counter disk 27 is advanced by the shaft 26 by one pitch every revolution of the shaft to decrease the displayed count of remaining film frames by one every exposure.
The front cover section 12 is formed with a finder window 36 and a lens hole 37 in its front wall 12a. The lens hole 37 is defined by a circular boss 37a. This boss 37a covers the lens mount 31 and the margin of the taking lens 32. The outer periphery of the taking lens 32 is pressed rearwardly by the inner surface of the boss 37a of the front wall 12a of the front cover section 12 attached to the main body 11. In such a way, the taking lens 32 is fixed between the front cover section 12 and the main body section 11. Due to the provision of the boss 37a for receiving therein the taking lens 32, it is possible to provide the necessary back focal distance while keeping the film package thin.
The front cover section 12 is formed in its front wall 12a with a vertically extending rectangular opening 38 in which the rectangular projecting cap 33 is received and a horizontally extending rectangular opening 39 in which the film rewinding knob 18 is received. The front cover section 12 is further formed in its top wall 12b with a counter opening 41 through which the exposure counter disk 27 can be viewed.
The front cover section 12 is further provided with a shutter release member 40 connected to top wall 12b by an integral elastic bridge 40a. The shutter release member 40 thus formed can be resiliently depressed when pressed with a finger and return upon removing the finger. The shutter release member 40 is provided with an integrally formed shutter release lever 40b extending downwardly therefrom. The lower end of the shutter release lever 40b is engaged by the hook lever 25.
The front cover section 12 is further formed in its front wall 12a with an opening 42 through which a mold for molding the shutter release lever 40b is withdrawn and openings 43 through which molds for molding hooks on the back surface of the front wall 12a are withdrawn. Engaging openings 44 formed in the front wall 12a of the front cover section 12 are engaged by hooks 13b formed integrally with a cover of the back cover section 13 which will be described in detail hereafter. Formed in the front wall 12a of the front cover section 12 are a pair of openings 48a and 48b through which a short circuit rod 58 having electrically integral contact points 58a and 58b is inserted for test discharging of the electronic flash unit 50 that will be described in detail later. Designated by numeral 59 is a flash discharge button for triggering a flash.
The back cover section 13 is attached to the main body section 11 to close light-tightly the film patrone-receiving chamber 14 and the film take-up chamber 15, and the exposure chamber 20. For securely shielding the film from light, the back cover section 13 is welded to the main body section 11 by ultrasonic welding or a special attaching mechanism so as not to be detached by users. The back cover section 13 is formed at the bottom with an integral bottom cover 13a flexibly hinged to the bottom edge thereof. The bottom cover 13a is formed with the hooks 13b along its front edge which are received in and engaged by the engaging openings 44 of the front cover section 12 to close the bottom opening of the film patrone-receiving chamber 14. The back cover section 13 is formed in its back wall with a horizontally extending narrow opening 46 in which the film rewinding knob 18 is received. The film rewinding knob 18 partly extends outside the film package to be operated with fingers. The back cover section is further formed in its back wall with a finder opening 47 in alignment with the front finder opening 36 formed in the front cover section 12.
The film package is assembled by attaching the front cover section 12 to the main body section 11 through the engagement of the detents 28 of the main body section 11 with hooks (not shown) of the front cover section 12 and then ultrasonically welding the back cover section 13 to the main body section 11, and thereafter engaging the hooks 13b of the bottom cover 13a of the back cover section 13 with the engaging openings 44 of the front cover section 12. The assembled film package is shown in FIGS. 5 and 6.
As shown in FIG. 5, the assembled film package contains the periphery of the film rewinding knob 18, and the ratchet 19 in mesh with the peripheral teeth of the film rewinding knob 18 is disposed in the horizontally extending rectangular opening 39 formed in the front wall 12a of the front cover section 12. The vertically extending projecting cap 33 of the lens holder plate 30 is disposed in the vertically extending rectangular opening 38. Thus, as is shown in FIG. 6, the top forward portion of the periphery of the film rewinding knob 18 and the front surface of the vertically extending projecting cap 33 are slightly behind the front surface of the front wall 12a of the front cover section 12. Therefore, the thickness of the film package has been reduced to the sum of the diameter of the film rewinding knob 18 and the thickness of the front wall 12a of the front cover section 12, less the distance by which the film rewinding knob 18 overlaps the thickness of the front wall 12a.
As seen in FIG. 5, the top of the boss 37a is cut away horizontally. The cut-away portion of the boss 37a provides enough space between the lens opening 37 and the front finder window 36 to allow that part of the external cardboard or plastic container between the openings of the external container that expose the taking lens and the front finder window to be formed desirably wide. Such wide bridging parts between openings help prevent breakage of the external container.
It is to be noted that the front cover section may be formed with other openings which receive therein parts, if permissible, projecting in an axial forward direction from the main body section 11 and that the back cover section can be formed with openings which receive therein parts projecting in an axially rearward direction from the main body section 11.
As is shown in FIG. 7, the electronic flash unit 50 attached to the main body section 11 comprises a reflector 51 having a parabolic reflective surface disposed behind the diffusion glass 50a, a discharge tube 52 disposed along the horizontal axis of the parabolic reflective surface of the reflector 51, and a flash power source (not shown). A cylindrical condenser 53 is vertically disposed behind and to the right of the reflector 51.
A circuit board 55 on which a flash control circuit is printed is disposed in front of the film take-up chamber 15. The condenser 53 is connected to the flash control circuit as well as to short-circuit terminals 56a and 56b disposed on the circuit board 55 correspondingly to the openings 48a and 48b of the front cover section 12a, respectively. The short-circuit terminals 56a and 56b on the circuit board 55 can be electrically connected by means of the short-circuit rod 58 of which contact arms 58a and 58b are inserted through the access openings 48a and 48b to short circuit the condenser 53.
The main body section 11 on which the electronic flash unit 50 is installed is attached to and covered by the front cover section 12. Then, before loading a film, the electronic flash unit 50 is subjected to a test discharge. For this, the short-circuit rod 58 is used. If the discharge tube 52 properly flashed when short-circuiting the condenser 53 with the short-circuit rod 58, the short-circuit rod 58 is kept inserted in the access openings 48a and 48b to maintain the condenser 53 fully discharged until a film patrone and a rolled unexposed film are loaded and the back cover section 13 is attached to close light-tightly the film patrone-receiving chamber 14 and the film take-up chamber 15.
After having completely assembled the film package but before inserting it into an external container, the short-circuit rod 58 is removed.
Referring to FIG. 8, there is shown an external container 61 made of a printable cardboard or printable plastic material for receiving therein the film package shown in FIGS. 3 to 6. As shown, the external container 61 is formed with openings 63a, 63b and 63c in its front wall 62a for exposing the boss 37a that receives and encloses the taking lens 32 therebehind, the front finder window 36 and the diffusion glass 50a of the electronic flash unit 50, respectively. The external container 61 is further formed with an openable portion 67 defined by three perforated lines 69 in the bottom wall 62b. The openable portion 67 is so located as to overlie the bottom cover 13a of the back cover section 13 when the film package is encased and is formed similar to but slightly larger than the outline of the bottom cover 13a of the back cover section 13. A tab 68 is defined by a semi-circular perforated line in one of the three perforated lines 69. The tab 68 is partly separated from the bottom wall 62b of the external case 61 for being easily picked up and peeled off with the fingers.
The external container 61 has an end flap 62c which is closed and adhesively secured thereto after inserting the film package thereinto so as to form an end wall of the external container 61.
After the use of the film package, as is shown in FIG. 9, the openable portion 67 of external container 61 is broken or torn off along the perforated lines 69 by pulling on the tab 68 with the fingers to expose the bottom cover 13a of the back cover section 13. Then, the bottom cover 13a is opened by disengaging the hooks 13b from the engaging openings 44 of the front wall 12a of the front cover section 12. Thereupon, the patrone 16 can be easily removed axially. The removed film patron 16 containing the exposed film is then handled in the same manner as conventional film patrones, while the film package is scrapped.
Referring now to FIG. 10, there is shown another external container 61 made of a printable cardboard or printable plastic material for receiving therein a film package shown in FIG. 11. In FIG. 11, parts and elements which are identical in structure and operation to those of the film package shown in FIGS. 3 to 6 are designated by similar reference characters, and therefore need not be described in detail herein. The film package shown in FIG. 11 is generally similar in construction to the film package shown in FIGS. 3 to 6. The only difference of the film package shown in FIG. 11 is that a power source of the electronic flash unit 50 such as a battery 80 is received in an open-bottom battery chamber 81 formed adjacent the bottom opening of the film patrone-receiving chamber 14 in the film package. The battery 80 in the open-bottom battery chamber 81 is held in place by a section 13c integrally formed with the bottom cover 13a when the bottom cover 13a of the back cover section 13 is closed to close the film patrone-receiving chamber light-tightly, whereby the battery 80 is prevented from leaving the film package.
As shown in FIG. 10, the external container 72 is formed with openings 63a, 73b and 73c in its front wall 72a for exposing the boss 37a receiving and enclosing the taking lens 32 therebehind, the front finder window 36 and the diffusion glass 50a of the electronic flash unit 50, respectively. The external container 72 is further formed with a generally L-shaped openable portion 77 defined by perforated lines 79 in the bottom wall 72b of the external container 72. The openable portion 77 is so located as to overlap the bottom cover 13a and the open bottom battery chamber 81 of the film package when the film package is encased, and is formed similar to but slightly larger than the outline of the bottom cover 13a and the open-bottom battery chamber 81 of the film package. In more detail, the L-shaped openable portion 77 comprises a stem portion 77a and an arm section 77b for covering the open-bottom battery chamber 81 and the bottom cover 13a, respectively.
A tab 78 is defined by a semi-circular perforated line in one of the three perforated lines 79. The tab 78 is partly separated from the bottom wall 72b of the external case 72 for being easily picked up and peeled off with fingers.
After the use of the film package, the openable portion 77 of the external case 72 is broken or torn off along the perforated lines 79 by pulling on the tab 78 with the fingers to expose the bottom cover 13a and the battery chamber 81 of the film package. Then, the bottom cover 13a is opened by disengaging the hooks 13b from the engaging openings 44 of the front wall 12a of the front cover section 12. Thereupon, the patrone 16 and the battery 80 can be easily removed. The film patrone 16 taken out is then handled in the same manner as conventional film patrones while the film package and the battery are scrapped separately.
In any embodiment described above, it is to be noted that the external container 61 or 72 may be provided with an opening through which a finger can be inserted, in place of the tab 67 or 78 and that, instead of forming the cover section and the perforated line for defining the openable portion in the bottom wall of the main case section and the external container, respectively, the bottom cover may be formed either in the back cover section or in an end wall of the front case section, and hence the perforated line may be correspondingly formed either in the back wall or in an end wall of the external container, respectively. It is also to be noted that the roll of photographic film can be used without being advanced frame by frame into a patrone or cartridge.
Furthermore, though in the above-described embodiments the openings 48a and 48b are formed in the front wall of the front cover section 12, the openings 48a and 48b may be defined in any other wall, for example in an end wall. That is, the position of the openings 48a and 48b may be located according to the position of the circuit board 55. Instead of the pair of openings 48a and 48b, one opening may be formed if the short-circuit rod 58 can be inserted through the opening. The condenser 53 and flash power source may be disposed in another position instead of behind the reflector 51.
Although the present invention has been fully described by way of preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention as defined by the appended claims, they should be construed as included therein. | A lens-fitted photographic film package has at least an unexposed rolled film, a taking lens, a film transportiong mechanism, an exposure mechanism and an electronic flash as a whole contained in a light-tight case. The light-tight case comprises a main case section formed with a chamber containing therein light-tightly the unexposed rolled film and a front cover section attached to the main case section, the front cover section being formed with at least one opening for partially receiving therein a member of at least one of the mechanisms mounted on the main case section projecting beyond a plane defined by surfaces of the main case section in contact with an inner surface of the front cover section when the front cover section is securely attached to the main case section. The electronic flash unit is short-circuited to maintain the condenser of the flash unit discharged until the rolled film has been loaded in the light-tight case, so as to prevent accidental flashing that would expose the film. The lens-fitted photographic film package is enclosed in an external container having a weakened openable portion capable of being broken away from the external container to expose the contained rolled film for removal after exposure. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national phase application of PCT Application No. PCT/GB2009/002841, filed Dec. 8, 2009, which claims priority to United Kingdom Patent Application No. 0822375.2, filed Dec. 9, 2008, the entire contents of which are both hereby incorporated by reference herein.
BACKGROUND
[0002] The present invention relates to a hydraulic coupling and more particularly, but not exclusively, to such a coupling of the kind that is used to interconnect hydraulic fluid flow lines in sub sea applications.
[0003] Hydraulic couplings are used, for example, to interconnect hydraulic fluid lines associated with sub sea wellheads and/or the assembly of valves, spools and other fittings known in the drilling industry as the “christmas tree”. The hydraulic fluid, which may be, for example, control fluid or an injected chemical for cleaning or otherwise treating the pipeline, the well, or christmas tree components, may be supplied under pressure from a floating vessel or a shore location. The couplings generally comprise male and female connectors having seals that are disposed at the junction between them when the coupling is complete. In many applications multiple hydraulic lines are bundled together into an umbilical string and multiple couplings are required to interconnect the respective lines. In such an arrangement the connectors are supported on respective manifold plates (often referred to in the art as “stab plates”) that are brought together to couple the connectors, and therefore the lines, together. The stab plates are typically transported and brought into register either manually by sub sea divers or by using a remote operated vehicle (ROV).
[0004] In one typical hydraulic coupling the male and female connectors are in the form of cylindrical bodies with internal bores. At a mating end of each connector the bore is of a relatively large diameter for sealed engagement with the mating end of the other connector and at the other end the bore has a relatively small diameter where it is connected to the hydraulic line via a check valve. The male connector is inserted axially into the relatively large diameter bore of the female connector and sealed thereto by a seal located in the bore. When the connectors are sealed, further axial movement causes actuators associated with the respective check valves to be displaced such that they are open and allow hydraulic fluid to flow through the sealed coupling. The seals prevent ingress of seawater into the hydraulic fluid line and the egress of hydraulic fluid out of the coupling. When the male and female connectors are disconnected the check valves are biased to a closed position so that hydraulic fluid cannot leak out into the environment.
[0005] One of the problems associated with such couplings is the large force required to connect or disconnect them, when the coupling is filled with hydraulic fluid. When the male and female connectors are engaged and moved axially towards each other to complete the connection, a force has to overcome the resistance provided by a small volume of incompressible seawater trapped in the internal bores by the seals. The forces acting on the seals serve to resist connection or disconnection, particularly under the hydrostatic head of seawater. Disconnection can be a problem as a low pressure or partial vacuum is created within bores that serves to resists disengagement of the male and female connectors. The forces required to connect and disconnect are multiplied when a plurality of such couplings are used on a pair of stab plates.
[0006] The check valves in hydraulic couplings of the kind described above are generally in the form of poppet valves with a conical or frusto-conical valve member whose outer face is designed to seal against a corresponding valve seat surface defined in the internal bore. The effective sealing of such valves can be problematic as it is important to manufacture the respective surfaces to a fine tolerance to ensure a good seal. In some instances the valve seat is defined at a significant axial distance along the inside of the connector and it can be difficult to achieve the required quality of finish in the machining process.
[0007] In the event that a check valve does not perform to the requisite standard the coupling is generally removed and replaced in its entirety.
SUMMARY
[0008] It is one object of the present invention to obviate or mitigate the aforementioned disadvantages. It is another object of the present invention to provide for an alternative, or improved, hydraulic coupling.
[0009] According to a first aspect of the present invention there is provided a hydraulic coupling a male connector having a body defining a male member, an internal bore in the body and a first check valve for controlling fluid flow through the internal bore; a female connector having a body defining an internal bore with a chamber for receipt of the male member and a second check valve for controlling fluid flow through the internal bore; the male and female connectors each having a respective mating end; an actuator disposed between the first and second check valves for moving the first and second check valves between an open position in which hydraulic fluid may flow through the respective internal bore and a closed position in which the flow is interrupted, depending on the distance between the first and second check valves; the male and female connectors being movable between an uncoupled position in which the mating ends are separated and the first and second check valves are in the closed position and a coupled position in which the male and female connectors are engaged at their mating ends and extend along a longitudinal axis; wherein the first and second check valves are each removable from the respective mating ends of the male and female connectors.
[0010] The ability to remove of the check valves from the mating ends enables the valves to be replaced, service or repaired in-situ without having to remove the whole coupling. This is much quicker and easier than compared to prior art hydraulic couplings.
[0011] The first and second check valves preferably form part of a removable check valve assembly that may comprise a valve member and a valve seat. It may further comprise a valve cage that supports the valve member. The first and second check valves may be ball check valves. Each ball check valve may comprise a ball valve member biased against a valve seat by a biasing member such as a spring. The spring may be supported on a member such as a spigot that limits travel of the ball valve member away from the valve seat. The valve seat may comprise a principal seat which may, for example, be made of PEEK and a back-up seat, that may for example, comprise an annulus of metal.
[0012] The male and female connectors may each comprise an outer body with a removable insert. The first or second check valve may be removable once the respective removable insert has been removed. The outer body of the female and the male connectors may be substantially identical.
[0013] The removable insert of the male connector may define the male member and the removable insert of the female connector may define the chamber. The removable inserts may be threadedly connected in the respective outer bodies and they may abut or receive a respective one of the first and second check valves.
[0014] The outer bodies may each define a port for connection to a hydraulic line. The connection may be provided, for example, by a thread defined on a surface that defines the port.
[0015] The first and second check valves may be movable by the actuator to interrupt or permit flow through the respective port to the hydraulic line.
[0016] According to a second aspect of the present invention there is provided a hydraulic coupling comprising: a male connector having a body defining a male member, an internal bore in the body and a first check valve for controlling fluid flow through the internal bore; a female connector having a body defining an internal bore with a chamber for receipt of the male member and a second check valve for controlling fluid flow through the internal bore; the male and female connectors each having a respective mating end; an actuator disposed between the first and second check valves for moving the first and second check valves between an open position in which hydraulic fluid may flow through the respective internal bore and a closed position in which the flow is interrupted, depending on the distance between the first and second check valves; the male and female connectors being movable between an uncoupled position in which the mating ends are separated and the first and second check valves are in the closed position and a coupled position in which the male and female connectors are engaged at their mating ends and extend along a longitudinal axis; wherein the first and second check valves are first and second ball check valves.
[0017] Conventionally poppet check valves are used in hydraulic couplers with an actuator that is fixed to, or forms an integral part of, the poppet valve.
[0018] The actuator is preferably not fixed to either of the first and second ball check valves. One end of the actuator may be in abutment with the first ball check valve. It may be in abutment even when the connectors are not coupled.
[0019] The actuator may be of any suitable shape in cross-section and may be an elongate member supported by one or other of the male or female connectors. The actuator may be supported in the internal bore of the male member. Preferably there is a clearance between the internal bore and the actuator to allow for the flow of fluid along the actuator. The clearance may be defined by recess, grooves or otherwise defined in the surface of the actuator.
[0020] The actuator may have a stop feature for engagement with a surface defined in the internal bore of the male member to limit its movement in the direction away from the first check valve. The stop feature may be a stepped shoulder defined on the actuator and the surface may be a stepped shoulder defined in the internal bore of the male member. The actuator may be held in abutment with the first check valve by the engagement of the stop feature with the surface defined in the internal bore.
[0021] The male and female connectors may each comprise an outer body with a removable insert.
[0022] The first and second ball check valve may each comprise a ball valve member biased against a valve seat by a spring. The spring may be supported on a spigot that limits travel of the ball valve member away from the valve seat. The valve seat may comprise a principal seat made of any suitable material such as, for example, PEEK and a back-up seat comprising an annulus of any suitable material such as, for example, metal.
[0023] According to a third aspect of the present invention there is provided a hydraulic coupling comprising: a male connector having an outer body defining an internal bore in which there is a removable insert defining a male member, and a first check valve for controlling fluid flow through the internal bore; a female connector having an outer body defining an internal bore in which there is a removable insert defining a chamber for receipt of the male member, and a second check valve for controlling fluid flow through the internal bore; the first and second check valves being movable between open and a closed position by an actuator; the male and female connectors being movable between an uncoupled position in which the first and second check valves are biased to the closed position and a coupled position in which the male member is received in the chamber of the female connector in a sealed relationship and the male and female connectors interact so as to move the actuator to urge the first and second check valves to the open positions; wherein the outer bodies are substantially identical.
[0024] The actuator may move the first and second check valves between an open position in which hydraulic fluid may flow through the respective internal bore and a closed position in which the flow is interrupted, depending on the distance between the first and second check valves.
[0025] The male member may have an engagement portion that occupies the chamber of the female connector in a sealed relationship when in the coupled position. The engagement portion may have an external surface for sealing against an internal surface of the chamber.
[0026] A first annular seal may be disposed in the chamber of the female connector, the sealed relationship being provided by the first annular seal in sealing engagement with the external surface of the engagement portion. A second annular may seal between the external surface of the engagement portion and the internal surface of the chamber.
[0027] The outer bodies may each define a port for connection to a hydraulic line.
[0028] The actuator may comprise an elongate member supported by one or other of the male or female connectors. The actuator is supported in the internal bore of the male member. A clearance between a wall defining the internal bore and the actuator may be provided to allow the passage of fluid along the actuator.
[0029] The male and female connectors may each comprise an outer body with a removable insert. The removable insert of the male connector may define the male member and the removable insert of the female connector may define the chamber. The removable inserts may each abut a respective one of the check valves.
[0030] According to a fourth aspect of the present invention there is provided a hydraulic coupling comprising: a male connector having a body defining a male member, and having an internal bore and a first check valve for controlling fluid flow through the internal bore; a female connector having a body defining an internal bore with a chamber for receipt of the male member and a second check valve for controlling fluid flow through the internal bore; an actuator disposed between the first and second check valves for moving the first and second check valves between an open position in which hydraulic fluid may flow through the respective internal bore and a closed position in which such flow is interrupted, depending on the distance between the first and second check valves; the male and female connectors being moveable between an uncoupled position in which the check valves are in the closed position and a coupled position in which the male and female connectors are engaged and extend along a longitudinal axis with the male member having an engagement portion that occupies the chamber of the female connector in a sealed relationship, the engagement portion having an external surface; a first annular seal disposed on the engagement portion of male member; a second annular seal disposed in the chamber of the female connector; the sealed relationship being provided by the first annular seal in sealing engagement with a first sealing surface defined by the chamber of the female connector and the second annular seal in sealing engagement with a second sealing surface defined on the external surface of the engagement portion of the male member; wherein in the coupled position the first and second annular seals are spaced apart in the chamber at opposite ends thereof and the distance between the first and second check valves is such that the actuator urges them to their open positions.
[0031] The arrangement ensures that fluid (such as seawater in the instance of the coupling being used sub sea) trapped between the male and female connectors is allowed to escape when the connectors are moved between the uncoupled and coupled positions. The disposition of the first and second annular seals allows the trapped fluid to escape before the engagement portion of the male connector and the chamber of the female connector enter the sealed relationship. Moreover, once the sealing relationship is complete any remaining trapped fluid does not significantly resist further axial engagement of the connectors in the coupled position since the actuator urges check valves are open to allow flow out of the coupling.
[0032] The arrangement is such that the connectors are sealed together at opposite ends of the chamber only when the connectors have reached the end or near the end of the length of relative travel required to attain the coupling position.
[0033] The first and second annular seals may be arranged such that they enter the sealing relationship substantially simultaneously when the male and female connectors are moved from the uncoupled to the coupled position. For example, the distance between the first annular seal and the sealing surface on the engagement portion of the male member may be substantially equal to the distance between the second annular seal and the sealing surface defined by the surface of the chamber.
[0034] The engagement portion may extend along part or substantially all of the length of the male member.
[0035] In the sealed relationship a radially outer surface the first annular seal is supported by the first sealing surface of the chamber of the female connector and a radially inner surface of the second annular seal is supported by the second sealing surface of the engagement portion.
[0036] The first and second annular seals may comprise one or more suitable sealing elements. For example they may include an O-ring and a supplementary seal or a pair of supplementary seals disposed on each side of an O-ring.
[0037] The second sealing surface may be provided on a terminal tip of the engagement portion of the male member. The terminal tip may have a diameter that is larger than an adjacent part of engagement portion.
[0038] The internal bore of the female connector may comprise a relatively large diameter bore with an open end for receipt of the male connector and relatively small diameter bore in which the second check valve is disposed.
[0039] The first sealing surface and the second sealing surface may occupy substantially the same diameter with respect to the longitudinal axis. This means that the forces applied by the pressurised fluid at the first and second annular seals are substantially equal.
[0040] The first annular seal may be supported in a groove in the male member and the second annular seal may be supported in a groove in the chamber of the female connector.
[0041] The actuator may take any suitable form and may be supported by one or other of the male or female connectors. For instance it may comprise an elongate member, such as a pin which may have paths such as channels, recesses or the like to allow the passage of fluid along its length. The actuator may be supported by the male connector such as in the internal bore defined by the male member. It may have the cross-sectional shape of a cross. The actuator is preferably of a predetermined length such that it engages the first and second check valves so as to urge them to the open position when the male and female connectors are moved to the coupled position.
[0042] The male and female connectors may each comprise an outer body with a removable insert which may be removably connected by any suitable connection means including for example a thread, a bayonet type fitting or any suitable latched connection. This provides for a modular configuration and the outer bodies of the female and the male connectors may be substantially identical and therefore interchangeable. The removable insert of the male connector may define the male member and the removable insert of the female connector may define the chamber. The removable insert for the male connector may abut the first check valve and the removable insert for the female connector may abut the second check valve.
[0043] The removable insert of the male connector may project from the outer body of the male connector and the removable insert of the female connector may project from the outer body of the female connector, the projecting part of the male insert being received in the chamber of the female connector and the projection part of the female insert being received between the outer body and the insert of the male connector.
[0044] The outer bodies may receive the respective check valves whereas the inserts may be designed to interconnect the connectors of the coupling. The removable insert may be sealed to the respective outer body of each connector by an appropriate seal. The internal bore of the male connector may comprise a first portion defined by the outer body and which may house the first check valve and a second portion defined by the removable insert and which may receive the actuator.
[0045] The outer bodies of each male and female connector may each define a port for connection to a hydraulic line. The first check valve may be disposed between the removable insert of the male connector and the respective port and similarly the second check valve may be disposed between the removable insert of the female connector and the respective port.
[0046] The first and/or second check valve may comprise a removable cartridge which may comprise a movable valve member and a valve seat against which the valve member seals when in the close position. The movable valve member may be biased to the closed position by a biasing member which may be any form of resilient member such as, for example, a spring. The valve member may be in the form of a ball. When the male and female members are in the coupled position the actuator may engage each valve member so as to move it, against the biasing force of the biasing member, away from the respective valve seat. A supplementary valve seat may be provided in addition to the (principal) valve seat and which acts to seal against the valve member should the principal valve seat fail.
[0047] The valve cartridge may comprise a stop that limits the length of travel of the valve member away from the valve seat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0049] FIG. 1 is a cross-section view along line A-A of FIG. 2 , the plane of the section intersecting the longitudinal axis of a hydraulic coupling in accordance with at least one aspect of the present invention, the coupling shown disconnected and mounted on respective supports;
[0050] FIG. 2 is an end view of the coupling of FIG. 1 ;
[0051] FIG. 3 is a view corresponding to that of FIG. 1 with the coupling shown in a position just before being fully coupled;
[0052] FIG. 4 is a view corresponding to those of FIGS. 1 and 3 , with the coupling shown fully coupled;
[0053] FIG. 5 is an axial cross-section of an alternative coupling embodiment in accordance with at least one aspect of the present invention, the coupling shown disconnected;
[0054] FIG. 6 is a view corresponding to that of FIG. 5 , with the coupling shown in a first partially coupled position;
[0055] FIG. 7 is a view corresponding to that of FIG. 5 , with the coupling shown in a second partially coupled position; and
[0056] FIG. 8 is a view corresponding to that of FIG. 5 , with the coupling shown fully coupled.
DETAILED DESCRIPTION
[0057] Referring now to the FIGS. 1 to 4 of the drawing the hydraulic coupling, indicated generally by reference numeral 10 , comprises male and female connectors 11 , 12 both of which are generally cylindrical and have identical outer bodies 13 each with an interior bore 14 .
[0058] In FIG. 1 , the male and female connectors 11 , 12 are depicted in coaxial alignment just prior to their connection. They are brought into register by relative axial movement towards each other to a position as shown in FIG. 3 where they are almost fully coupled and then further moved in the same direction to complete the engagement and provide a sealed connection as shown in FIG. 4 .
[0059] Each of the interior bores 14 has a relatively large diameter opening 15 at a mating end and a relatively small diameter port 16 at the opposite end. The port 16 is internally threaded for connection to an end fitting of a hydraulic fluid line (neither of which are shown in the figures). From the large diameter opening 15 the internal bore 14 extends rearwardly towards the port 16 and is radially inwardly stepped at 17 such that it separates the bore 14 into a first chamber 14 a that is designed to receive a male or female nose insert 18 , 19 and a second bore 14 b in which a check valve assembly 20 is disposed.
[0060] The female nose insert 19 is generally cylindrical with an internal bore defining a chamber 21 for sealing engagement with the male nose insert 18 . The insert 19 has a first end 22 that abuts the check valve assembly 20 and a second end 23 for mating with the male nose insert 18 of the male connector 11 . An external surface of the female nose insert 19 has a threaded portion 24 at the first end 22 to allow screw connection to a corresponding threaded portion in the wall of the internal bore 14 of the outer body 13 . Further towards the second end 23 of the insert 19 , the outer surface has a pair of axially spaced annular grooves 25 , 26 designed to receive seal elements for sealing against the internal surface of the outer body 13 . The seal elements in each groove 25 , 26 each comprise an O-ring seal 27 , 28 and a back-up annular PTFE seal 29 , 30 . These serve to seal together the two parts (i.e. the outer body 13 and the female nose insert 19 ) of the female connector 12 against the ingress or egress of fluid. It is to be appreciated that other appropriate seal elements may be used. The surface of the internal chamber 21 of the female nose insert 19 similarly has an annular groove 32 disposed axially between the groove 25 and the first end 22 and receives an O-ring seal 33 disposed between a pair of PTFE secondary seals 34 (it will again be appreciated that any suitable sealing arrangement may be provided). This seal arrangement is designed to provide a sealed connected between the male and female connectors 11 , 12 when fully coupled together.
[0061] The male nose insert 18 has a first end 40 for engagement with the check valve assembly 20 and an elongate second end 41 for connection to the female nose insert 19 . The first end 40 has substantially the same diameter as the corresponding part of the female nose insert 19 and the outer surface has a threaded section 42 (at the first end 40 ) for screw-threaded engagement with a corresponding threaded portion defined on the surface of the internal bore 14 of the outer body and a pair of axially spaced annular grooves 43 , 44 for receipt of seal elements. Each of the annular grooves 43 , 44 houses an O-ring seal 45 and a back-up PTFE seal 46 for sealing engagement with the surface of the inner bore 14 of the outer body 13 . Once again, it is to be appreciated that any suitable sealing arrangement may be provided. The second end 41 is elongate and designed to be received in the chamber 21 of the female nose insert 19 . It has a further annular groove 47 defined on its external surface, adjacent to the intermediate portion 41 and for receipt of sealing elements designed to seal with the female nose insert 19 when the two connectors 11 , 12 are engaged. The sealing elements are identical to those provided in groove 32 of the female nose insert 19 and comprise an O-ring 48 sandwiched between PTFE secondary annular seals 49 . The second end 41 has a further reduced diameter portion 50 defined between the region where the seals 48 , 49 are supported and a terminal tip 51 designed to seal against the seals 33 , 34 provided in the female nose insert 19 .
[0062] The male nose insert 18 is penetrated by an internal bore 52 that receives an elongate actuator pin 53 that has the shape of a cross in cross-section. There is a small radial clearance between the pin 53 and the bore. This clearance together with the spaces between the limbs of the cross afford paths for hydraulic fluid to flow along the pin 53 when the coupling is complete. The actuator pin 53 , which projects slightly from the first end 40 and more significantly from the second end 50 , is not fixed to either of the check valve assemblies 20 . It is held captive in the bore 52 by a stepped shoulder 70 that engages with a corresponding stepped shoulder 71 formed in the internal surface of the bore 52 to prevent the pin 53 being withdrawn out of the mating end of male nose insert 19 . The engagement of the stepped shoulders 70 , 71 thus limit movement of the actuator away from the check valve assembly of the male connector 11 .
[0063] The check valve assemblies 20 are each identical in the form of a cartridge 54 having a plastics or metal cage that supports a valve ball 55 and its seat 56 . The cartridge 54 is received in the second chamber 14 b of the bore 14 with the cage receiving the valve ball 55 which is retained in place by an annular valve seat 56 of any suitable material such as, for example, PEEK (polyetheretherketone) that abuts against the first end 22 , 40 of the respective female or male nose insert 19 , 18 . The ball 55 is biased towards the respective valve seat 56 by a spring 57 supported on a spigot 58 that also acts to limit the travel of the ball 55 away from its seat 56 . A small annulus of metal 59 is received in the valve seat 56 and also abuts the first end 22 , 40 of the respective insert 19 , 18 and serves as a back-up seat to the PEEK seat 56 .
[0064] It will be seen from FIG. 1 that when the male connector 11 is assembled such that the male nose insert 18 is secured to the outer body 13 by the threads 42 , its second end 41 projects significantly from the large opening 15 whereas the first end 40 abuts against the valve seat 56 and back-up seat 59 of the check valve cartridge 54 with one end of the actuator pin 53 projecting from the tip 51 of the second end 41 and the opposite end abutting against the ball 55 of the check valve cartridge 54 .
[0065] Similarly, when the female connector 12 is assembled its second end 23 projects slightly from the large opening 15 of the outer body 13 .
[0066] In each connector 11 , 12 the check valve assembly 20 is biased closed by means of the spring 57 urging the ball 55 against the seat 56 such that hydraulic fluid flowing from the connected line into the respective connector 10 , 11 through the port 16 is prevented from egressing into the internal bores 14 .
[0067] In order to connect together the two halves of the coupling 10 , the second ends 23 , 41 of the male and female nose inserts 18 , 19 are presented to each other as shown in FIG. 1 . The longitudinal axes of the two connectors 11 , 12 are aligned such that the second end 41 of the male nose insert 18 can be received in the chamber 21 of the female nose insert 19 and the second end 23 of the female nose insert 19 can be received within the outer body 13 of the male connector 11 when the two connectors 11 , 12 are moved axially towards one another as depicted in FIG. 3 . In this position the two connectors 11 , 12 are brought into register but are not fully engaged and are not yet sealed to each other. In particular, the surface of the chamber 21 of the female nose insert 19 is about to pass over the seals 48 , 49 on the outer surface of the second end of the male nose insert 18 and, similarly the outer surface of the tip 51 of the second end of the male nose insert 18 is about to pass inside the seals 33 , 34 in the internal annular groove 32 of the female nose insert 19 . At this point the ends of the actuator pin 53 abut the respective balls 55 of the check valve assemblies 20 . Prior to this point any seawater trapped in the chamber 21 of the female nose insert 19 has been allowed to escape by virtue of a small radial clearance between the external surface of the second end of the male nose insert 18 and the internal surface of the chamber 21 of the female nose insert 19 .
[0068] In order for the two connectors 11 , 12 to become fully sealed to each other and for the two check valves 20 to open, the connectors 11 , 12 must be axially displaced further towards each other by the very short distance x shown in FIG. 3 until the outer bodies 13 abut one another.
[0069] The connectors 11 , 12 are shown fully engaged in FIG. 4 . In this position the radially inner surface of seals 33 , 34 of the female nose insert 19 are supported on a sealing surface defined on the outer surface of the tip 51 of the male nose insert 18 and the radially outer surface of the seals 48 , 49 on the outer surface of the male nose insert 18 are brought into engagement with a sealing surface defined by the inner surface of the chamber 21 of the female nose insert 19 . At substantially the same time the ends of the actuator pin 53 forces the balls 55 of the check valve cartridges 54 from their respective seats 56 against the force of the respective biasing springs 57 so as to open the valves and allow hydraulic fluid to flow through the coupling 10 via the paths defined by the actuator pin 53 .
[0070] The two connectors 11 , 12 are shown mounted on respective supports 60 which in this case are designed to receive only one connector each. Each of the connectors 11 , 12 is received in an aperture in the respective support 60 and is retained in position by a circlip 61 that is received in an annular groove 62 in the external surface of the outer body 13 . In another embodiment 11 , 12 the connectors may be welded or otherwise fixed to their supports 60 . In a yet further embodiment the supports 60 may be designed to receive multiple connectors 11 , 12 that are coupled to each other when the opposite supports 60 are aligned and brought together.
[0071] The provision of seals 33 , 34 and 48 , 49 at opposite, axially spaced, ends of the mating parts of the male and female connectors 11 , 12 affords a secure sealing arrangement. Moreover, by ensuring that the sealing surface of each sealing arrangement is at the same diameter, the respective forces on the seals are balanced such that there is no tendency to inhibit connection or separation of the connectors 11 , 12 .
[0072] The seals 33 , 34 and 48 , 49 are positioned such that sealing between the male and female connectors 11 , 12 is made effective just as the check valve assemblies 20 are opened by the actuator pin 53 . This means that any remnant of seawater left in the chamber 21 can pass into the hydraulic line. The sealing is configured such that it does not take effect until the connectors 11 , 12 are almost fully engaged (between the positions depicted in FIGS. 3 and 4 ) so that the trapped volume of seawater is substantially negligible and significantly less than in prior art couplings. Similarly, the arrangement allows easy disconnection of the coupling 10 as the check valve 20 is free to close at the point the sealing is broken so that the separation force does not have to act against the force applied by a partial vacuum.
[0073] The use of ball check valves is beneficial over conventional poppet valve designs as the contact sealing area is smaller and is not reliant to the same degree on machining tolerances and surface finishes, resulting in lower spring forces required to hold the valves in the closed positions, leak free.
[0074] The above described design lends itself to a modular configuration in which a single outer body 13 and check valve cartridge 54 can be used for both the male and female connectors 11 , 12 with just the nose inserts 18 , 19 being selected to determine whether the connector is male or female. The screw-threaded connection between the inserts 11 , 12 and the outer bodies 13 allows for simplified manufacture and assembly. Moreover, it allows for ease of servicing, repair or maintenance of the check valve cartridges 54 as they can be accessed and removed easily from the mating end of each of the connectors 11 , 12 in-situ i.e. without the need to remove the whole connector 11 , 12 from its respective support 60 . The male or female nose insert 18 , 19 is simply disconnected from the respective outer body 13 by unscrewing it to provide access to the check valve cartridge 54 .
[0075] Each of the seal arrangements is housed in grooves 32 , 47 which provide protection to the seals when under pressure. Moreover the provision of secondary seals 34 , 49 affords additional security.
[0076] The main valve seat (PEEK) 55 is provided with a back-up metal annulus 57 that not only prevents permanent deformation of the main seat 55 at high operating temperatures but also provides an emergency seat should the main seat 55 fail.
[0077] It is will be appreciated by one of ordinary skill in the art that the invention has been described by way of example only, and that the invention itself is defined by the claims. Numerous modifications and variations may be made to the exemplary design described above without departing from the scope of the invention as defined in the claims. For example the check valves may be of any suitable form. Moreover, the material used for each component can be varied to comply with the temperature or pressure requirements of the particular application.
[0078] A second embodiment of the hydraulic coupling having many design features similar to those of the coupling of FIGS. 1 to 4 will now be described with respect to FIGS. 5 to 8 . Components that correspond to those of the embodiment of FIGS. 1 to 4 have been given the same reference numeral but increased by 100 and are not further described except insofar as they differ from their counterparts.
[0079] The male and female parts of the hydraulic coupling of FIGS. 5 to 8 are shown separate from any support such as that indicated by reference numeral 60 in the above embodiment but it will be understood that it is intended to be used in the same manner. The coupling differs primarily in that seals between the male and female connectors are provided in the female connector only and in that the valves are positioned closer to the mating ends of each connector so that the actuator can be made shorter in length. This renders it less susceptible to damage in circumstances where large forces are required to connect and disconnect the coupling.
[0080] The male and female connectors 111 , 112 again comprise identical outer bodies 113 each with an interior bore 114 . In FIG. 5 the male and female connectors are shown separated before connection and in coaxial alignment. The interior bores 114 each receive, as before, a respective male and female nose insert 118 , 119 . In contrast to the inserts 18 , 19 of the previous embodiment, the internal bores in these inserts 118 , 119 are configured to receive the check valve assemblies 120 which are again in the form of removable cartridges. Each cartridge comprises a cage 175 and a seat 156 which are connected together and receive between them a ball 155 . The cage supports a spring 157 that acts on one side of the ball 155 to bias it towards the seat 156 . As in the previous embodiment the seat may take any form and material but in one example it is an annular component of PEEK. The outer surface of the cartridge has a groove in which an O-ring seal resides 177 , the seal acting against an internal surface of the respective nose insert 118 , 119 .
[0081] The actuator 153 is again an elongate member that is received in the internal bore 152 of the male nose insert 118 . In this particular embodiment the actuator is substantially triangular in cross-section although it is to be appreciated that it may take any suitable shape provided it allows for the flow of fluid between its surfaces and the surface of the internal bore 152 . As before, movement of the actuator away from the check valve assembly 20 of the male connector 111 is limited by inter-engagement of stepped shoulders 171 , 172 defined on the actuator 153 and in the internal bore 152 . These serve to hold the actuator in abutment with the ball 155 of the check valve assembly in the disconnected state shown in FIG. 5 .
[0082] In each case the nose inserts 118 , 119 have a flange 176 at the mating end that abuts against an end of the outer body 113 . The flange 176 of the female nose insert 119 is thicker than that of the male nose insert 118 and defines the chamber 121 in which the second end of the male nose insert 118 is received.
[0083] The elongate second end 141 of the male nose insert 118 is designed to be received in the chamber 121 of the female nose insert 119 as before. The chamber 121 has two axially spaced seals 133 , 148 that are received in respective grooves and are intended to seal against the outer surface of the elongate second end 141 of the male nose insert 118 . The seals 133 , 148 are axially spaced along the chamber 121 . A first of the seals 133 , nearest to the mating end, is in two parts comprising a graphite annulus alongside a PTFE annulus. A second of the seals 148 comprises a graphite annulus alongside a beryllium clamping ring. The two parts to the seal ensure there is a back-up seal provided in one of the parts fails. It will be understood that any suitable form and material for each seal may be used and that the back-up part of the seal is optional. For example, the graphite annulus may be replaced by any sort of elastomeric material.
[0084] In FIG. 6 the male and female connectors 111 , 112 have been moved axially towards one another such that the elongate second end 141 of the male nose insert 118 is received in the chamber 121 of the female connector 112 such that it is in a sealing relationship with the seal 133 . At this point the leading end of the actuator 153 abuts the ball 155 of the check valve assembly 120 in the female connector 112 . Further axial movement towards each other causes the actuator to move at the ball 155 in the female connector 112 away from its seat 156 against the biasing force of the compression spring 157 , thereby opening the check valve 120 as shown in FIG. 7 . This allows trapped fluid such as seawater to escape into the flow line. At this position the connectors 111 , 112 are almost fully coupled.
[0085] In FIG. 8 the connectors 111 , 112 are shown fully engaged such that the flanges 176 of each nose insert 118 , 119 are in abutment and the elongate second end 141 of the male nose insert 118 is sealed against the wall of the chamber 121 by both seals 133 and 148 . It will be seen that both balls 155 are moved from their respective seats 156 against the force of the biasing springs 157 such that the hydraulic fluid can flow through the coupling.
[0086] The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the scope of the inventions as defined in the claims are desired to be protected. It should be understood that while the use of words such as “preferable”, “preferably”, “preferred” or “more preferred” in the description suggest that a feature so described may be desirable, it may nevertheless not be necessary and embodiments lacking such a feature may be fall within the scope of the invention as defined in the appended claims. In relation to the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary. | A hydraulic coupling for sub sea applications comprises inter-engageable male and female connectors. The male connector defines a male member for receipt in a chamber defined by the female connector. Each connector has a respective check valve for controlling the flow of fluid through internal bores in the connectors. The check valves are actuable by an actuator between an open position in which hydraulic fluid may flow through the respective internal bore and a closed position in which such flow is interrupted, depending on the distance between the first and second check valves. The male and female connectors are moveable between an uncoupled position in which the check valves are in the closed position and a coupled position in which the male and female connectors are engaged and extend along a longitudinal axis with the male member occupying the chamber of the female connector in a sealed relationship. A pair of seals are provided one on the male member and the other on the in the chamber. The seals are arranged so that they seal the chamber at opposite ends by sealing against respective sealing surfaces in the coupled position. The distance between the first and second check valves in the sealing position is such that the actuator urges them to their open positions. The arrangement ensures that seawater between the connectors is allowed to escape before the sealing relationship is established and, upon coupling, the check valves are opened to allow fluid to flow. | 4 |
BRIEF SUMMARY OF THE INVENTION, Background and Objectives
My invention concerns the injection of an amount of chlorine into a swimming pool measured by time resulting from a constant delivery pressure to an elastomeric disperser tube having needle punctures acting as a size of fixed sized orifices under that pressure.
For convenience, the specification and claims herein will use the expression "swimming pools", but spas are also serviced by pool services as to chlorine injection and the terms "swimming pool" or "swimmings pool" should be interpreted to include spas.
In the maintenance of swimming pools, pool services commonly are hired to visit the pool to perform maintenance and cleaning tasks. One important task is to restore the level of absorbed chlorine in the swimming pool water to a needed value. The level of absorbed chlorine is measured and the service person then knows the amount of chlorine needed to be added to restore the level of absorbed chlorine to the proper level in a pool of that size. Usually the amounts of chlorine are stated in terms of pounds of liquid chlorine. This practice is at least partly because in the past the way the service person knew how much was delivered from a container of liquid chlorine was by poolside weighing of the container before and after injection on some type of portable scale. Commonly, one or two pounds of chlorine is injected from a cylinder weighing as much as fifty pounds. Weighing the amount of chlorine injected to within 1/4 pound, a desired accuracy, is very difficult with light weight portable weighing devices rugged enough to withstand rough usage and a chemical corrosive environment. Control of the flow of chlorine is by means of adjusting the cylinder valve. This is a sensitive adjustment and sometimes the flow is too great and the bubbles of chlorine are too large to be completely absorbed. Objectives of my invention include to provide a different manner of measuring injected chlorine than weighing chlorine cylinders and to control rate of injection of chlorine by other measures in addition to adjusting the cylinder valve. It is an objective of my invention to control the weight of chlorine injected by measuring the time of injection rather than to weigh the chlorine cylinder.
In the injection of chlorine, the liquid in the cylinder boils to liberate the gas and this gas is transfered through a disperser tube to the bottom of the pool at the deep end and dispersed into small bubbles by passing thru small holes in the wall of a closed end tube. The bubbles should be small enough that the chlorine dissolves in the water before reaching the surface. In the past the disperser tube has had holes drilled in a tube that would pass some bubbles too large to dissolve if the cylinder valve were opened too far. It is an objective to avoid that problem and, more specifically to avoid too large bubbles by use of a pressure regulator and by use of a multiplicity of punctures in an elastomeric disperser tube. It is a further objective to avoid plugging of holes in a disperser tube by using such punctures that open under pressure and close in absence of pressure.
Another objective is to provide fluorinated polymers in the disperser tube and in contact with chlorine in the pressure regulator so as to provide corrosion resistance.
A further objective is to provide a swimming pool chlorine injection means and method that best adapts to field conditions, considerations and objectives in the commercial swimming pool maintenance field. The ways the present means and method adapts to field conditions, considerations and objectives will be further discussed below in conjunction with the description of the invention.
My invention will be best understood, together with additional advantages and objectives thereof, when read with reference to the drawings.
DRAWINGS
FIG. 1 is a perspective view of a specific embodiment of my chlorine injection equipment in a swimming pool.
FIG. 2 is a view of my equipment schematically presented.
FIG. 3 is a sectional view of a disperser tube showing punctures forming outlets in the tube and a needle used to make the punctures.
FIG. 4 is similar to FIG. 3 but shows the outlets expanded under pressure and passing bubbles.
FIG. 5 is similar to FIG. 4 but the section is taken transversely of the tube.
FIG. 6 is an exploded perspective view of the pressure regulator assembly in my equipment.
DESCRIPTION
In commercial pool maintenance, it is desirable that operations be adapted for average workers that may include some people not careful in handling equipment or conducting operations. For example, some workers may subject equipment to rough usage, i.e., throw or drop apparatus in the bed of a pickup truck. Portable scales for weighing cylinders are especially subject to damage from rough usage. As will appear below, my system is to inject by timing rather than by weighing, so use of scales to govern amount of chlorine injected is avoided.
Some workers may be careless in opening liquid chlorine cylinder valves resulting in too large bubbles being injected from a disperser tube and an excessive rate of failure of chlorine to absorb in swimming pool water. Pressure in cylinders heated by the sun can get so high that too much gas may be emitted even when the valve is opened with care. An integral part of my system is to use a pressure regulator in measuring amount of chlorine being injected by unit of time and the pressure regulator also avoids excessive injection pressures.
As in many commercial activities, amount of time spent by a worker to accomplish a job is a primary consideration. Control of the amount of chlorine injected in my new system is by a stop watch and the service person can be conducting other maintenance operations while the stop watch is running. Use of a stop watch for injection control saves time over using a portable scale during chlorine injection in the prior practice. Another desirable objective is for the pool service person to by able in one trip to carry (usually to the backyard) everything needed for a pool maintenance, so this helps define applicable apparatus.
The primary components of my chlorine injection system include a cylinder 10 of liquid chlorine, a transfer tube 12 and a disperser tube 14. During injection, disperser tube 14 is disposed near the bottom of a swimming pool 16 filled with water, cylinder 10 is disposed at the side of pool 16, and transfer tube 12 connects cylinder 10 to disperser tube 14. All parts in contact with chlorine gas flowing from cylinder 10 should be formed from a fluorinated material such as TEFLON or VITON manufactured by du Pont or KYNAR PVDF manufactured by Penwalt. I prefer to use Viton fluoroelastomer for disperser tube 14 and transfer tube 12. A pressure regulator 18 is provided and I prefer to form parts of pressure regulator 18 in contact with chlorine gas of KYNAR PVDF.
As before indicated, one difficulty in injecting chlorine into a pool in prior practice is that when the cylinder valve 20 is opened or "cracked", flow may be excessive, even when the service person is careful, much less when the service person gets careless. Excessive flow means that gas bubbles 42 emitted from disperser tube 14 are too large and do not get sufficiently absorbed in the water in pool 16 above disperser tube 14 before they break the surface. Escape of chlorine from the water in pool 16 not only is wasteful and does not serve its sanitary purposes but also may damage plants in the pool area. This is one reason why I provide pressure regulator 18, preferably set about 30-35 psig. Pressure of chlorine gas in cylindrs 10 can get very high, i.e., when heated in the sun pressures of 150 psig are not uncommon. The level of pressure to tubes 12, 14 is set by regulator 18 at a level so that bubbles of gas 42 emitted from disperser tube 14 will not be excessive in size. The nature of the openings or outlets 40 from disperser tube 14, etc., is also influential on bubble size, i.e., if the openings 40 were too large then too large bubbles 42 might still be formed, a subject I will further discuss below. Controlling pressure out of cylinders 10 by watching a pressure gauge is not suitable because such gauges are too delicate for pool service usage wherein cylinders 10 may be dropped into pickup beds. Corrosion of gauges from chlorine gas also would be a problem.
The pressure regulator 18 depicted in FIG. 6 is of mostly conventional construction except for the use of VITON or KYNAR PVDF for parts in contact with chlorine gas. That material will accept to temperatures and corrosiveness of chlorine gas without significant deterioration. Such parts include valve 21, body 22, washer 24, diaphragm 26, and valve stud 27 that secures valve 21 to spring plate 28. I prefer KYNAR for parts other than the diaphragm which I prefer to make of VITON reinforced by glass filaments. Spring plate 28, spring 30, and cap 32 can be formed of metal as they are not in contact with the chlorine gas. Usually a pressure regulator has an adjusting screw acting on a spring adjust washer to vary the compression on spring 30. I prefer to omit such adjusting screw because pool service personnel might adjust the screw so the pressure regulator would no longer regulate at the preferred pressure. Instead I adjust compression of spring 30 with one or more washer or disc shims 34 at the outer end of spring 30, so service personnel are unable to adjust or tamper with the pressure regulator spring pressure setting. As pressure regulator 18 is of basically conventional operation, I will not burden this specification with a description of operation of its parts.
Transfer tube 12 is connected to cylinder 10 with a type of quick-disconnect coupling 36. Service personnel need to frequently change cylinders 10, as often as once for each pool serviced and may carry a half dozen cylinders 10 in the service vehicle. This is because when quantities of liquid chlorine are changed to gas in the process of feeding chlorine gas from cylinders 10, cooling occurs which reduces pressure in cylinders 10. Then a different cylinder needs to be used. When a used cylinder is disconnected, the relatively high temperatures external of the cylinder will gradually heat the cylinder contents again causing the chlorine liquid in the cylinder to boil and to reestablish gas pressure at a suitable level. A filter, not shown, may be also used between cylinder 10 and transfer tube 12.
A second reason to provide a pressure regulator 18 is that the addition of the pressure regulator to the pool chlorine injection system permits the amount of injected chlorine to be measured by time instead of by weight. Instead of using a portable scale to weigh chlorine cylinder 10 during injection, a stop watch is used to measure the time of chlorine injection. If the pressure of chlorine gas is established and if orifices in disperser tube 14 are fixed in sizes at that pressure, the amount of injected chlorine per unit of time can be established from prior charted data. To chart the amount of gas that will be injected per unit of time, one could weigh a chlorine cylinder during injection. It is more practical in production during charting to use air rather than chlorine gas and to use a flow meter to measure the air flow rather than to weigh the air during injection. Of course, the air involves no cost or disposal problem. A rate of five cubic feet of air injected per minute is the equivalent of one-half pound of chlorine per minute or one pound of chlorine in two minutes. Each new assembly of disperser tube 14, transfer tube 12, pressure regulator 18 and coupling 36 should be calibrated to confirm the rate that chlorine will be injected, although with proper manufacturing techniques the rates of injection will become somewhat uniform. An earlier manufacturing operation is to adjust each pressure regulator 18 to a selected value, i.e., 30-35 psig, by selection of shimming washers or discs 34. Experience has indicated that an injection rate of one pound of chlorine in two minutes can be controlled within plus or minus 0.05 pounds.
The design of the constant flow rate chlorine injector depends not only on pressure regulator 18 but also on a disperser tube 14 which has fixed sized orifices at the injection pressure. As before indicated, I have selected VITON fluoroelastomer to form disperser tube 14. This material has a hardness, Durometer A points, of 79. This material is able to handle the temperatures and corrosiveness of chlorine gas without significant deterioration.
I have discovered that a disperser tube 14 made from VITON fluoroelastomer has important advantages in my invention in addition to resistance to corrosiveness. The improvement involves the type of material and the nature of the outlet openings 40 in tube 14. The disperser is made by forcing thru the tube needles 0.035" in diameter. One configuration of punctures 40 but not the only one that would be workable is made by forcing a needle 60 thru both sides of the tube three times around the circumference 120° apart and by providing rings of these punctures 0.2" apart. One example is about 1,000 punctures 40 made this way. A second example is 500 punctures 40. The needle size is limited to a maximum size of 0.060" or bubbles of chlorine gas injected through openings 40 become so big as to break the surface of the water of a pool before being absorbed. Smaller needles 60 than 0.35" in diameter can be used but more punctures need to be made for the same rate of flow. Most of the pressure drop from regulator 18 occurs as the chlorine gas exits from disperser 14. The pressure of the gas in the disperser is adjusted by the regulator with the design that punctures 40 open enough to form small bubbles 42 which don't break the surface of the pool. Too high a gas pressure and insufficient punctures 40 would cause the gas to break the surface of the water at the flow rate desired.
FIG. 5 shows six openings 40 around the circumference of disperser tube 14. Examples of disperser tube dimensions are 3/8" O.D. and 3/16" I.D. FIG. 3 indicates tube 14 before gas pressure is applied in which the openings 40 are shown as a line, which means the needle punctures seem completely closed. In fact, when tube 14 is unpressurized, openings 40 only appear as faint marks on the surface of the tube. FIG. 4 indicated that under pressure openings 40 open up enough to inject gas in the form of bubbles 42 into the water in the swimming pool.
A peculiar feature of openings 40 in tube 14 is that if there are fewer openings they open wider to emit more bubbles per opening 40 or larger sized bubbles so that reduction in numbers of openings does not result in proportionately less gas flow. For example, consider a configuration in which pressure regulator 18 is set at 30-35 psig and the punctures 40 in VITON tube 14 has been pierced with 0.035" diameter needles 60. One thousand punctures 40 results in about 5.2 CFM of air flow, and five hundred punctures 40 results in about 3.26 CFM of air flow. This means that punctures 40 act as elastic orifices responsive to pressure, i.e., act as one size of orifices at one pressure and as different sized orifices at a different pressure. Punctures 40 evidently open wider if there are fewer openings to accommodate a given pressure. It appears the greater number of holes 40 the smaller bubbles 40 will be which should result in quicker absorption in water.
It was my prior practice to make the disperser tube 14 out of KYNAR PVDF and to drill openings 42 with a jeweler's drill, i.e., about 350 holes 1/4" apart with a diameter of about 0.014". The KYNAR tube was hard and the outlet openings in it had no significant elasticity if any elasticity at all.
The advantages of the VITON fluoroelastomer over the prior sized tube with small holes drilled in it include:
1. The VITON tube disperser 14 produces much smaller bubbles 42 for better absorption in pool water.
2. The punctures can not become plugged as the holes in the rigid disperser do either from deposited impurities or by burrs bending back over the holes.
3. The punctures do not allow the back flow of water into the disperser when the flow of gas is stopped as does the rigid disperser. Water in a disperser with cold water below 48° F. can plug holes by the formation of solid chlorine hydrate.
4. It is much simpler and less time consuming to puncture a VITON rubber tube with needles 60 than to drill small holes in a rigid tube.
Disperser tube 14 can be several feet long. Openings 40 should not be too close together so that bubbles 42 from adjacent holes 40 will not coalesce to form larger bubbles. Also, if the outlet openings 40 were too close there might not be a sufficient volume of water above tube 14 to absorb the chlorine and that water could become oversaturated. Disperser tube 14 could have the form of a star or spider instead of the single length of tubing depicted. Disperser tube 14 should be spaced from the bottom of the pool because if it touches the pool surface the bubbles tend to coalesce into larger bubbles, so disks 50 are used to support all or most of tube 14 above the swimming pool bottom. Lead weights (not shown) may be attached to disks 50 to weigh down disperser tube 14.
Transfer tube 12 may be around fifteen feet long, to connect between cylinder 10 at the side of pool 16 to disperser tube 14 or the pool bottom. Disperser tube 14 is usually put in the deep end of pool 16 which may be eight or ten feet deep.
Apparatus to puncture tube 14 with needles 60 will be understood by those skilled in manufacturing operations. One way is to mount a needle in a drill press and support the tubing suitably to make the series of punctures. FIG. 3 has a representation of a needle 60 used to puncture tube 14.
Amount of chlorine to be injected into swimming pool water depends on pool size (usually 20,000 gallons, sometimes 40,000 gallons) and by measurement of the level of chlorine in the water. Then by consulting a chart developed by tests, the pool service person can tell how long to operate my new injection system in order to add the number of pounds of chlorine needed. While watching the time on a digital stop watch, the service person can conduct other pool service operations.
Having thus described my invention, I do not wish to be understood as limiting myself for the exact construction shown and described. Instead, I wish to cover those modifications of my invention that will occur to those skilled in the art upon learning of my invention and which are within the proper scope thereof. | A chlorine injector for a swimming pool including a cylinder of chlorine, a disperser tube near the bottom of the pool, and a transfer tube therebetween. The disperser tube is formed of a fluorinated elastomer and has a multiplicity of discharge orifices formed by needle punctures normally closed but opening up responsive to pressure. A pressure regulator between the cylinder and the transfer tube having ports in contact with chlorine gas made of fluorinated material. Addition of chlorine to the pool being controlled by time of injection with constant pressure set by the pressure regulator and by fixed sizes of discharge orifices formed by the punctures under that constant pressure. Disk spacers supporting the disperser tube above the pool bottom. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Ser. No. 815,653, entitled Conditioning of Semiconductor wafers for Uniform and Repeatable Rapid Thermal Processing, (Texas Instruments case number T-16323), filed on Dec. 31, 1991 by Moslehi et al.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates generally to semiconductor device electrical testing and more particularly to apparatus for performing electrical testing on semiconductor devices at various temperatures including elevated temperatures in wafer form.
In semiconductor technology, electronic devices and circuits are made on one semiconductor wafer. They each have various components on them; these components may include transistors, resistors, capacitors, and others. After the circuit has been fabricated, individual components or circuit modules in selected circuits can be probe tested to determine the electrical characteristics of the various components. In the development phase of semiconductors, characteristic tests over a wide temperature range are typically performed in order to test device reliability and performance under temperature stress. Other temperature-dependant tests are performed during production in order to monitor the quantities or presence of certain elements such as mobile ion contaminants that may be introduced during the processing of the material.
Pat. No. 4,567,432 entitled "Apparatus for Testing Integrated Circuits" filed on Jun. 9, 1983 by Buol et al describes a system for testing an integrated circuit die in wafer form at various temperatures. The system involves a resistively-heated wafer chuck which includes a means for heating and/or cooling the wafer via an electrical heating element and refrigerant gas.
While nothing in prior art suggests or teaches the use of a Rapid Thermal Processing chuck or susceptor for probe testing of semiconductors, or the use of such a chuck in or with a probed test fixture, several patents have been issued for the production of semiconductors using Rapid. Thermal Processing. One such patent is U.S. Pat. No. 4,891,499 filed Sep. 9, 1988 by Moslehi, entitled "Method and Apparatus for Real-time Wafer Temperature Uniformity Control and Slip-Free Heating on Lamp Heated Single-wafer Rapid Thermal Processing Systems". Another such patent is U.S. Pat. No. 4,830,700 filed Apr. 27, 1988 by Davis et al entitled "Processing Apparatus and Method" wherein the processing apparatus also utilizes Rapid Thermal Processing. In these Rapid Thermal Processing (RTP) patents the semiconductor wafer is placed either device side down or device side up in a vacuum or atmospheric chamber prior to the processing stages at relatively high temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described with reference to the accompanying drawings, wherein:
FIGS. 1 and 2 each show an elevation of a preferred embodiment.
FIGS. 3 (through 6 show other embodiments.
SUMMARY OF THE INVENTION
In the past, probe stations have utilized high thermal mass resistance heated metal chucks with water coolant to expedite the cooling process. These chucks were rather massive and time-consuming to use. Past chucks were of a thick gauge of metal (at least 1/2"), and thus required a large amount of time to heat and cool (e.g. approximately half an hour for the cycle). When a semiconductor wafer underwent electrical tests at elevated temperatures, the wafer, chuck and probe were raised to an elevated temperature in order for the tests to be conducted. With resistance heating, a relatively massive chuck is required to obtain uniform heating. The testing time at elevated temperatures is quite long because of the time it takes to heat and cool the high thermal mass resistively heated chuck.
This new invention allows for much more rapid changes in temperature of the wafer than with prior test systems, with very stable results and robust temperature control. The apparatus includes a wafer support, a rapid thermal processing (RTP) illuminator (that is used to heat the wafer), and electrical probe needles to contact the wafer. The RTP illuminator consists of lamps, preferably tungsten-halogen bulbs, and is capable of heating the susceptor and the wafer quite rapidly and uniformly.
In one embodiment, the wafer support is a ting with a hole in the center. In another embodiment, the ring has a center portion that is transparent (e.g. made of quartz) immediately underneath the wafer. One embodiment involves an opaque and optically absorbing wafer support that is thermally conductive with a low thermal mass. In yet another embodiment, the wafer support is a transparent window, made of a material such as quartz that is generally transparent to the light from the heating lamps. Another version involves a thin gauge (about 1/16") low-thermal mass conductive susceptor to support the wafer, which is mounted on a transparent window, thermally insulating the wafer frown the window. The wafer can be held into place on the susceptor or transparent window by either a vacuum, clamps or other mechanism.
These embodiments provide electrical probe test fixtures that generally have a wafer support either having low thermal conductivity to the wafer or low thermal mass, or both, and can reduce testing time up to tenfold over the past chucks, particularly for electrical tests at more than one temperature between room temperature and one or more elevated wafer temperatures.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The making and use of the presently preferred embodiments are discussed below in detail. However, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts where the rapid heating and cooling of low thermal mass objects is desirable. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the invention.
The following is a description of a preferred embodiment followed by a method of using the invention. Other versions of the apparatus will then be described, followed by some suggested alternate components. Corresponding numerals and symbols in the different figures refer to corresponding parts unless otherwise indicated. Table 1 below provides an overview of the elements of the embodiments and the drawings.
TABLE 1__________________________________________________________________________ PreferredDrawing or SpecificElement Examples Generic Term Other Alternate Examples__________________________________________________________________________10 n/a Apparatus n/a12 Black Susceptor MONEL, graphite, silicon Anodized carbide, or any metal with Aluminum, low thermal mass (e.g. no 1/16" thick greater than 1/4" thickness).14 Holes in Holding means Clamps, electrostatic, or other susceptor mechanisms to hold the wafer in place, e.g. vaccuum clamp.15 Clamps Holding means Holes, electrostatic.16 n/a Semiconductor n/a wafer17 Aluminum Wafer Support Metal, silicon carbide, silicon, or a trans- graphite, or any other parent supportive material that window would withstand the testing temperature (e.g. ceramic or metal).18 Quartz Transparent Sapphire, glass or other window transparent material.20 Tungsten Rapid Thermal Other radiant lamps or bulbs Halogen Processing (RTP) such as plasma arc lamp or Lamp illuminator any blackbody heater.22 n/a Probe needles n/a24 n/a Thermocouple n/a25 n/a Wires n/a26 n/a Cover n/a28 Holes in Holding means Clamps, electrostatic, or other window mechanisms to hold the wafer in place.30 Aluminum Ring Metal, silicon carbide, graphite or any other supportive material that would withstand the testing temperature.32 Quartz or Center Portion of Metals or any material that is Aluminum Ring either transparent or thermally conductive.__________________________________________________________________________
In semiconductor wafer fabrication, it is, for example, important to periodically monitor furnace tubes and metal deposition equipment for mobile ions (e.g. Na or K), which are a contaminant. If an excessive level of mobile ions are present, production must be halted until the source of contamination is eliminated in the production equipment. A test called Fast Bias Temperature Stress is a measure of the amount of mobile ions present on the wafer. Throughout the industry, this test is run on a periodic basis, generally at least daily.
Currently, when a semiconductor wafer is undergoing Fast Bias Temperature Stress test a CV (Capacitance/Voltage) reference curve is first taken on a test capacitor at room temperature. The entire wafer and probe is then raised to 250 degrees C. Next, an electrical signal is applied to the capacitor on the wafer under test, the measurement for Fast Bias Temperature Stress is begun, and then the system is cooled back down again with the voltage applied. Finally, a second CV curve is taken and compared to the first CV curve. The magnitude of the shift in the curve under high-temperature electric field stress is proportional to the concentration of mobile ions present in the device under test. This cycle of heating, testing and cooling has previously taken 20 to 30 minutes.
The Fast Bias Temperature Stress test is initialized at 250 degrees C., in order for the mobile ions to move within the gate oxide. However, this temperature is actually only necessary for a short time (e.g. a millisecond); the remainder of time is spent heating and cooling the probe station due to the large thermal mass of the chuck.
FIG. 1 shows a preferred embodiment of the apparatus 10, comprised of a thin-gauge low-thermal mass conductive (such as thin black anodized aluminum) susceptor 12, which can have holes 14 in it so a vacuum can be applied under the susceptor 12 (thus holding the semiconductor wafer 16, in place). The susceptor 12 is mounted on top of a transparent window 18, and is comprised of a material such as quartz that generally is transparent to the tungsten-halogen light. Beneath the susceptor are several heating bulbs forming the RTP illuminator 20. In this embodiment, the susceptor 12 thermally insulates and separates the wafer 16 from the transparent window 18.
Also included are electrical probe needles 22, which come into contact with the top surface of the wafer for electrical measurements. There is relative movement, both horizontally and vertically, between the probe needles and the wafer allowing contacts to be made to various device electrodes. A thermocouple 24 is located near the center of the susceptor which is connected to an instrument for temperature measurement and closed-loop control (not shown). A probe station cover 26 can be placed on top of the entire assembly while the wafer is undergoing tests. In this embodiment, the semiconductor wafer is preferably mounted face-up and is bottom-illuminated.
To test for Fast Bias Temperature Stress utilizing the apparatus, first the probe needles are moved to the particular circuit to be tested on the wafer. Next, the RTP illuminator is used to rapidly (e.g. in 20 seconds or less) elevate the temperature of the wafer to 250 degrees C. (or any other desired elevated temperature) and held at that temperature for approximately 30 seconds. A voltage is then applied through the probes to the particular component (e.g. a capacitor) of interest. The apparatus and wafer are allowed to cool in ambient temperature with the voltage applied, and the capacitance is measured and recorded after the wafer cools.
There are many other temperature-dependent phenomena that can be tested with the apparatus, such as diode leakage, current drive, and other activation energy measurements and characterizations. These types of tests are used frequently for reliability measurements and characterization of a semiconductor wafer.
FIGS. 2 through 6 illustrate alternate versions of the apparatus. FIG. 2 again shows the apparatus 10, upon which the wafer 16 is mounted face-up on top of the low thermal mass susceptor 12 without vacuum, and with clamps 15 to hold the wafer in place. Probe needles 22 and thermocouple 24 are positioned over semiconductor wafer 16.
In FIG. 3, the apparatus 10 is another alternative, with the wafer 16 mounted directly on a wafer support 17 (which in this case is a transparent window 18), under which the RTP illuminator 20 is located. The window is shown with holes 28 in it, so a vacuum may be applied in order to hold the wafer in place. Probe needles 22 contact the wafer from the top side.
FIG. 4 shows the apparatus 10 comprised of a wafer support 17 (which in this case is a ring 30 which holds wafer 16). The RTP illuminator 20 and probe needles 22 are located below and above the wafer support, respectively. FIG. 5 shows a similar apparatus 10 in which the wafer support 17 is a ring 30 with a center portion 32 directly underneath the wafer, which can be made of a transparent material. The wafer 16 is placed on the center portion 32 of the ring 30. Again, the RTP illuminator 20 and probe needles 22 are located below and above the wafer support, respectively.
FIG. 6 shows the apparatus 10 in which the wafer support 17, made of a low-thermal mass thermally conductive material, braces the wafer 16. The RTP illuminator 20 and probe needles 22 again are located below and above the support, respectively.
There are other alternatives available for the components of the system. Rather than holes and a vacuum to hold the wafer in place, mechanical clamps or other devices could be used to hold the wafer in place. The transparent window can also be made of sapphire, glass, or other transparent materials that would withstand the elevated temperatures. The system could operate without the susceptor or window, as some other wafer support could be provided (e.g., the support could be pins). The susceptor may be made of other metals than aluminum, such as MONEL, remembering that it is important to keep the thermal mass low, so a thickness of about 1/16" is appropriate. The thermocouple(s) could be located elsewhere in the system. See Table 1 for other possible alternates.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations .of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments. | An apparatus and method for rapidly changing the temperature of a semiconductor wafer, in order to perform electrical tests or stress at elevated temperature, and then cool rapidly to ambient temperature. The apparatus is comprised of a wafer support 17, capable of supporting the wafer, mounted on top of a rapid thermal processing (RTP) illuminator 20 (lamps, preferably halogen), and including one or more probe needles 22, capable of contacting the wafer to perform electrical measurements. A semiconductor wafer 16 is placed upon the wafer support 17 and the RTP illuminator 20 located beneath is activated, rapidly elevating the wafer to the desired temperature. Electrical tests may be performed as desired during the process. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/631,678, filed Nov. 29, 2004, the disclosure of which is incorporated herein by reference.
GOVERNMENT INTEREST
[0002] This invention was made with government support under grant DAAD: 19-01-0619 awarded by the Department of Defense. The government has certain rights in this invention.
BACKGROUND OF THE INVENTION
[0003] The present invention relates generally to stabilization of antioxidants and particularly to compositions and methods in which at least one antioxidant moiety and at least one UV-absorbing moiety are co-localized to enhance the stability of the antioxidant moiety in an environment in which photooxidation can occur.
[0004] Interest in combining the photocatalytic activity of titanium dioxide (TiO 2 ) and the biocatalytic activity of enzymes is growing. See, for example, Takashi, S.; Ryota, S.; Mikako, K.; Mayu, K.; Hirotaka, I.; Katsutoshi, O. Chem. Comm. 2004, 814-815; Ganadu, M. L.; Andreotti, L.; Vitali, I.; Maldotti, A.; Molinari, A.; Mura, G. M. Photochem. Photobiol. Sci. 2002, 1, 951-954; and Cuendet, P.; Grätzel, M.; Pélaprat, M. L. J. Electroanal. Chem. 1984, 173-185, the disclosures of which are incorporated herein by reference. Anatase type TiO 2 absorbs ultraviolet radiation (UV) having energy greater than its optical band gap of 3.2 eV and generates an electron-hole pair. Sandola, F. In Photocatalysis—Fundamentals and applications . Serpone, N.; Pelizzetti, E. Eds.; John Wiley and Sons: New York, 1989, pp 9-44, the disclosure of which is incorporated herein by reference. Interestingly, proteins are adsorbed onto TiO 2 via electrostatic interactions. See, for example, Klinger, A.; Steinberg, D.; Kohavi, D.; Sela, M. N. J. Biomed. Mater. Sci. 1991, 36, 387-392; Topoglidis, E.; Cass, A. E. G.; Gilardi, G.; Sadeghi, S.; Beaumont, N.; Durrant, J. R. Anal. Chem. 1998, 70, 5111-5113; and Topoglidis, E.; Campbell, C. J.; Cass, A. E. G.; Durrant, J. R. Langmuir 2001, 17, 7899-7906, the disclosure of which are incorporated herein by reference. Enzyme-TiO 2 “bio-inorganic hybrids” are being investigated for enhanced performance in catalysis and sensing. The interplay between TiO 2 and the enzyme can have effects on electron transfer rates in some active sites. For example, in the presence of photoexcited TiO 2 , glucose oxidase exhibits a five-fold rate enhancement in the reduction of oxygen to hydrogen peroxide. Takashi, S.; Ryota, S.; Mikako, K.; Mayu, K.; Hirotaka, I.; Katsutoshi, O. Chem. Comm. 2004, 814-815. Horseradish peroxidase-TiO 2 deposited on an electrode exhibited high rates of electron transfer from the enzyme to the electrode. Ganadu, M. L.; Andreotti, L.; Vitali, I.; Maldotti, A.; Molinari, A.; Mura, G. M. Photochem. Photobiol. Sci. 2002, 1, 951-954, the disclosure of which is incorporate herein by referenc. Nicotinamide adenine dinucleotide (NAD + ) has been efficiently reduced to NADH by lipoamide dehydrogenase in the presence of viologen and TiO 2 -UV. Cuendet, P.; Grätzel, M.; Pélaprat, M. L. J. Electroanal. Chem. 1984, 173-185, the disclosure of which is incorporate herein by reference.
[0005] Enzyme-TiO 2 -UV systems are also being considered for use in decontamination since the free radicals released by TiO 2 in the presence of UV-light exhibit bactericidal and fungicidal activity. See, Ibáñez, J. A.; Litter, M. I.; Pizarro, R. A. J. Photochem. Photobiol. A: Chem. 2003, 157, 81-85 and Wolfrum, E. J.; Huang, J.; Blake, D. M.; Maness, P-C., Huang, Z.; Fiest, J. Environ. Sci. Technol. 2002, 36, 3412-3419, the disclosures of which are incorporated herein by reference. Enzymes such as diisopropylfluorophosphatase and organophosphorous hydrolase degrade active nerve agents. See, for example, Drevon G. F.; Karsten, D.; Federspiel, W.; Stolz, D. B.; Wicks, D. A.; Yu, P. C.; Russell, A. J. Biotechnol. Bioeng. 2002, 79, 785-794 and LeJeune, K. E.; Mesiano, A. J.; Bower, S. B.; Grimsley, J. K.; Wild, J. R.; Russell, A. J. Biotechnol. Bioeng. 1997, 54, 105-114, the disclosures of which are incorporated herein by reference. Thus, biocatalytic activity can be combined with photocatalytic activity to develop protective coatings against wide range of chemical and biological agents. All these novel applications suffer from the problem of rapid inactivation of proteins and nucleic acids by the hydroxyl and superoxide radicals produced on the surface of photoexcited TiO 2 . See, for example, Hancock-Chen, T.; Scaiano, J. C. J. Photochem. Photobiol. B: Biol. 2000, 57, 193-196 and Wamer, W. G.; Yin, J-J.; Wei, R. R. Free Rad. Bio. Chem. 1997, 6, 851-858, the disclosures of which are incorporated herein by reference. Covalent modification of enzymes with polymeric stabilizers could protect the enzyme without affecting bulk TiO 2 activity. Indeed, covalent attachment of poly(ethylene glycol) (PEG) chains to proteins imparts steric stabilization against heat, pH and other deteriorating conditions. Poly ( ethylene glycol ) Chemistry: Biotechnical and Biomedical Applications . Harris, M. J. Ed. Plenum, New York, 1992, the disclosure of which is incorporated herein by reference. In the case of photooxidation, a UV-absorber and/or an antioxidant based polymer could stabilize the enzyme more efficiently than via PEGylation since PEG can be readily oxidized.
[0006] The stabilization of a model enzyme, chymotrypsin, against inactivation caused by TiO 2 -UV was recently described. Lele, B. S.; Russell, A. J. Biomacromolecules 2004, 5, 1947-1955, the disclosure of which is incorporated herein by reference. Conjugating the enzyme with UV-absorbing moieties, such as carboxyl terminated oligo(2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate) (oligo(HBMA)-COOH) reduced the rate of inactivation. Chymotrypsin-oligo(HBMA) conjugates (adsorbed on irradiated TiO 2 ) were stabilized because of the ability of HBMA moieties to compete with TiO 2 for the UV light thereby reducing the excitation of TiO 2 in the region of HBMA. However, upon continuous irradiation, the modified enzyme deactivated gradually because of the photooxidation of both HBMA and the enzyme by the free radicals. It is interesting to note that HBMA moieties did not absorb free radicals. Thus, the enzyme protection was derived solely from the reduction in the excitation of TiO 2 .
[0007] It remains desirable to develop improved compositions and method for the stabilizations of antioxidants and for the stabilization of enzymes.
SUMMARY OF THE INVENTION
[0008] Antioxidants (also sometimes referred to as free radical absorbers) sacrificially stabilize materials against free radicals (for example, free radicals generated from photooxidation as a result of exposure to sunlight). In the present invention, compositions, systems and methods for stabilization of an antioxidant against photooxidation are provided wherein an antioxidant is localized or co-localized with an ultraviolet-absorber (“UV-absorber”). As used herein the terms “localized” or “co-localized” refer to maintaining the antioxidant and the UV-absorber in relatively close proximity to each other (in volumetric space). The antioxidant and the UV-absorber are maintained in sufficiently close proximity such that a synergistic effect on stability is achieved. In that regard, the UV-absorbing moiety can be maintained in sufficiently close proximity to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur. Such localization or co-localization does not occur upon mere physical mixing of antioxidant and UV-absorber. The compositions and methods of the present invention thus provide enhanced stability as compared to compositions in which antioxidant and UV-absorber are merely physically mixed.
[0009] For example, the antioxidant can be localized with a UV-absorber within a single molecule (for example, within a single oligomeric or polymer chain). The antioxidant and the UV-absorber can, for example, be localized via covalent bonding in a reaction (for example, a copolymerization) of at least one monomer including or incorporating the antioxidant and at least one monomer including or incorporating the UV-absorber. Antioxidants and UV-absorbers can also be conjugated to a reactive polymer. The synergistic stabilization effects achieved in the present invention are useful in virtually any composition, system or process in which antioxidants are used, including, but not limited to: polymer stabilization, cosmetic and sun-screen additives, surface stabilizations, and enzyme stabilizations (including enzymatic sensor stabilizations). The compositions of the present invention can be mixed into such a composition or attached (via, for example, covalently bonding) to one or more components of the composition.
[0010] Without limitation of the present invention to any particular mechanism of operation, in a possible mechanism of operation of the present invention, localization or co-localization of a UV-absorber and a free radical absorber causes a decrease in concentration of inactivating species around the antioxidant and increases its life under photooxidizing conditions. Once again, such stabilization is not achieved by using physical mixtures of UV-absorber and antioxidant.
[0011] In one aspect, the present invention provides a composition including at least one antioxidant moiety and at least one UV-absorbing moiety. The antioxidant moiety and the UV-absorbing moiety are maintained in proximity to each other. The UV-absorbing moiety and the antioxidant moiety can, for example, be attached to a common entity. The antioxidant moiety and the UV-absorbing moiety can, for example, be covalently attached within a single molecule. The UV-absorbing moiety can be attached sufficiently closely to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur. In one embodiment, the UV-absorbing moiety is attached to the molecule to be juxtapositioned to the antioxidant moiety.
[0012] The UV-absorbing moiety and the antioxidant moiety can, for example, be attached to a single polymeric chain. The polymeric chain can be formed by reaction of at least a first monomer incorporating the UV-absorbing moiety and a second monomer incorporating the antioxidant moiety. The polymeric chain can also be formed by reacting a polymeric precursor with a first compound incorporating the UV-absorbing moiety and a second compound incorporating the antioxidant moiety.
[0013] The compositions of the present invention can be added to a material to stabilize the material. For example, the composition physically mixed with the material or attached to the material. In one embodiment, a single molecule including the antioxidant moiety and the UV-absorbing moiety is covalently attached to the material. The material can be virtually any material, including for example, be a polymeric material, a cosmetic, a sun screen, a protein or an enzyme. The enzyme can, for example, be supported on a free radical producing support. In one embodiment, the support includes at least one species which is a photocatalytic oxidant. In one embodiment, the enzyme is adsorbed on a particle of titanium dioxide.
[0014] In another aspect, the present invention provides an enzyme having attached thereto at least one group including at least one antioxidant moiety and at least one UV-absorbing moiety, each of which is attached to the group. In one embodiment, the group is covalently attached to the enzyme. The antioxidant moiety and the UV-absorbing moiety can, for example, be covalently attached to the group. The UV-absorbing moiety can be attached sufficiently closely to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur. The UV-absorbing moiety can, for example, be attached to be juxtapositioned to the antioxidant moiety.
[0015] In one embodiment, the UV-absorbing moiety and the antioxidant moiety are attached to a single polymeric chain. A precursor to the polymeric chain can be formed by reaction of at least a first monomer incorporating the UV-absorbing moiety and a second monomer incorporating the antioxidant moiety. A precursor to the polymeric chain can also formed by reacting a polymeric precursor with a first compound incorporating the UV-absorbing moiety and a second compound incorporating the antioxidant moiety.
[0016] In a further aspect, the present invention provides a composition including an enzyme supported on a free radical producing support. The enzyme has attached thereto at least one group comprising at least one antioxidant moiety and at least one UV-absorbing moiety as described above. The support can, for example, include at least one species which is a photocatalytic oxidant. In one embodiment, the enzyme is adsorbed on a particle of titanium dioxide.
[0017] In another aspect, the present invention provides a composition including at least one antioxidant moiety and at least one UV-absorbing moiety wherein the antioxidant moiety and the UV-absorbing moiety are tethered to be localized. The UV-absorbing moiety can be tethered sufficiently closely to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur. The UV-absorbing moiety can, for example, be tethered to the antioxidant moiety by attachment of the UV-absorbing moiety and the antioxidant moiety to a molecule as described above. The UV-absorbing moiety can also, be tethered to the antioxidant moiety by attachment to a common support.
[0018] In a further aspect, the present invention provides a method of stabilizing an antioxidant moiety including the step maintaining at least one antioxidant moiety and at least one UV-absorbing moiety sufficiently closely to enhance the stability of the antioxidant moiety in an environment in which photooxidation can occur. In one embodiment, the at least one antioxidant moiety and at least one UV-absorbing moiety are attached to a common entity to enhance the stability of the antioxidant moiety in an environment in which photooxidation can occur. The antioxidant moiety and the UV-absorbing moiety can, for example, be covalently attached to a single molecule. The UV-absorbing moiety can be attached to the molecule to be juxtapositioned to the antioxidant moiety. In one embodiment, the UV-absorbing moiety and the antioxidant moiety are attached to a single polymeric chain. The polymeric chain can be formed by reaction of at least a first monomer incorporating the UV-absorbing moiety and a second monomer incorporating the antioxidant moiety. The polymeric chain can also be formed by reacting a polymeric precursor with a first compound incorporating the UV-absorbing moiety and a second compound incorporating the antioxidant moiety.
[0019] In another aspect, the present invention provides a method of synthesis of a polymer including antioxidant and UV-absorber including the step of copolymerizing polymerizable antioxidants and polymerizable UV-absorbers.
[0020] In another aspect, the present invention provides a method of synthesis of a polymer including antioxidant and UV-absorber including the step of conjugating antioxidants and UV-absorbers to a reactive polymer.
[0021] In a further aspect, the present invention provides a composition including at least one antioxidant moiety and at least one UV-absorbing moiety. The antioxidant moiety and the UV-absorbing moiety are covalently attached within a single molecule wherein the UV-absorbing moiety is attached sufficiently closely to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur.
[0022] In still a further aspect, the present invention provides a method of adding an antioxidant to a material including the step of adding to the composition an antioxidant composition including at least one antioxidant moiety and at least one UV-absorbing moiety. The antioxidant moiety and the UV-absorbing moiety are covalently attached within a single molecule, wherein the UV-absorbing moiety is attached sufficiently closely to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur. The antioxidant composition can, for example, be mixed into the material. The antioxidant composition can also be attached to a component of the material. In one embodiment, the antioxidant composition is covalently bonded to the component of the material.
[0023] Antioxidants and UV-absorbers can be co-localized in a wide variety of polymers in the present invention. For example, various types of vinyl polymer backbones are suitable. Moreover, poly(acrylate)s, poly(methacrylate)s, poly(acrylamide)s, poly(methacrylamide)s, poly(allylic)s and other polymers are also suitable.
[0024] Polymerizable antioxidant and UV-absorbers can, for example, be prepared by conjugation reaction between functional monomers such as 2-hydroethyl methacrylate, 2-amioethyl methacrylate, 3-aminopropyl methacrylamide, UV absorber and antioxidant. Moreover, chain-end-functionalized co-oligomers of UV-absorber and antioxidant can, for example, be conjugated to high molecular weight reactive polymers such of poly(N-acryloxysuccinimide), poly(N-methacryloyloxysuccinimide), or poly(2-hydroxyethyl methacrylate).
[0025] As used herein, the terms “polymer” or “polymeric” refer to a compound or group having multiple repeat units (or monomer units) and includes the term “oligomer,” which is a polymer that has only a few repeat units (for example, dimer, trimer etc.). The term polymer also includes copolymers which are polymers including two or more dissimilar repeat units (including terpolymers—comprising three dissimilar repeat units—etc.).
[0026] A broad variety of antioxidants can be used in the present invention. In addition to other antioxidants described herein, various plasma antioxidants such as ascorbic acid, alpha tocopherol, glutathione, and uric acid can, for example, be stabilized. Other classes of antioxidants that can be stabilized include, but are not limited to, carotenoids (for example, beta carotene and lycopene); flavanones (for example, cyanidin, catachin, naringenin, malvidin, delphinidin, and anthocyanidin); flavon-3-ols (for example, quecetin and kaempferol); hydroxycinnamates (for example, ferulic acid, p-coumaric acid, and caffeic acid). Synthetic antioxidants that can be stabilized include, but are not limited to, various tert-butyl phenols and catachols.
[0027] Likewise, a broad variety of UV absorbers are suitable for use in the present invention. In addition to other UV absorbers described herein, UV-absorbers that can be used to stabilize antioxidants in the present invention include, but are not limited to, functionalized derivatives of triazine, benzophenone, and hindered aromatic amines.
[0028] The present invention, along with the attributes and attendant advantages thereof, will best be appreciated and understood in view of the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1A illustrates a hypothesized representation of the mechanism of deactivation of enzyme and antioxidant in the case of modified chymotrypsins against TiO 2 -UV when the UV-absorber and antioxidant are not co-localized.
[0030] FIG. 1B illustrates a hypothesized representation of the mechanism of enhanced stabilization of modified chymotrypsins against TiO 2 -UV as a result of the co-localization of the UV-absorber and antioxidant within a single chain.
[0031] FIG. 2A illustrates an ESI-APCI mass spectrum of oligo(HBMA)-COOH.
[0032] FIG. 2B illustrates an ESI-APCI mass spectrum of oligo(HBMA-co-Trolox-HEMA)-COOH.
[0033] FIG. 3A illustrates a MALDI-TOF spectra of native chymotrypsin.
[0034] FIG. 3B illustrates a MALDI-TOF spectra chymotrypsin-oligo(HBMA).
[0035] FIG. 3C illustrates a MALDI-TOF spectra of CTM-separate (chymotrypsin modified at separate positions on the enzyme).
[0036] FIG. 3D illustrates a MALDI-TOF spectra of CTM-single (chymotrypsin modified with HBMA and Trolox within a single chain attached to the enzyme).
[0037] FIG. 4 illustrates a schematic representation of the synthetic strategies used to obtain enzyme modifications.
[0038] FIG. 5A illustrates the effect of conjugated modifiers on the stability of chymotrypsins exposed to TiO 2 -UV wherein the data reported are average of duplicate experiments.
[0039] FIG. 5B illustrates the stabilization of Trolox activity in single-chain modified enzyme upon exposure to TiO 2 -UV.
[0040] FIG. 6 illustrates the retention of antioxidant activity by Trolox upon exposure to TiO 2 -UV in the presence or absence of adjacent UV-absorber wherein the data reported are average of duplicate experiments.
[0041] FIG. 7A illustrates CD spectra of native chymotrypsin.
[0042] FIG. 7B illustrates CD spectra of CTM-separate.
[0043] FIG. 7C illustrates CD spectra of CTM-single.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The use of enzymes in conjunction with inorganic photocatalysts requires stability against photooxidation. In several studies of the present invention, a representative example of an enzyme is modified by covalent attachment thereto of a polymeric (oligomeric) adduct incorporating a UV-absorbing moiety and an antioxidant moiety. In that regard, we describe enhanced stabilization of a model material (the enzyme, chymotrypsin) to photooxidation driven by titanium dioxide exposed to ultraviolet light (TiO 2 -UV). Stabilization is achieved by conjugating the enzyme with an oligomeric adduct of UV-absorbing (2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate) (HBMA) and free radical-absorbing 2-methacryloyloxyethyl-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylate (TROLOX®-HEMA). Juxtaposition or co-localization of the antioxidant Trolox (vailable from Hoffmann-La Roche Inc. of Nutley, N.J.) with the UV-absorber HBMA (for example, within a single chain) reduced the rate of deactivation of the former by TiO 2 -UV. This modification enables modified enzyme, which is adsorbed on TiO 2 , to absorb both UV-light and free radicals and locally reduce the rate of photooxidation. Interestingly, Trolox was more readily deactivated by TiO 2 -UV when it was conjugated separately to chymotrypsin that had been pre-modified with HBMA moieties.
[0045] One skilled in the art appreciates that the stabilization of antioxidants in materials demonstrated in the studies of the present invention is not limited to the representative proteins (for example, enzymes) set forth herein. Indeed, the co-localization of an antioxidant moiety and a UV-absorbing moiety of the present invention can be used to enhance the stability of virtually any type of material. The compositions of the present invention (in which an antioxidant moiety and a UV-absorbing moiety are co-localized) can, for example, be physically mixed with a composition or attached to a composition (for example, via covalent bonding) to enhance the stability thereof against photooxidation. Examples of compositions or materials which can be stabilized by the compositions of the present invention include, but are not limited to, polymers (both synthetic polymers and biopolymers such as proteins or enzymes), cosmetics, sun screens, surface treatments and colorants.
[0046] Given the strong oxidizing activity of TiO 2 -UV it was hypothesized that the antioxidant (which is basically an organic compound) might be more accessible for photooxidation when randomly conjugated to the enzyme. Conversely, by juxtapositioning the antioxidant with a UV-absorber there was a possibility that the enzyme could be protected from inactivation by maximizing the removal of free radicals. In the studies of the present invention, a two-fold enhancement in the stability of the modified enzyme against TiO 2 -UV was achieved by conjugating the native enzyme with an oligomeric adduct of UV-absorbing HBMA and a polymerizable derivative of Trolox, the free radical absorbing chroman ring in the antioxidant vitamin E. We demonstrated that TiO 2 -UV caused significant loss in the antioxidant activity of Trolox when it is randomly conjugated with the enzyme pre-modified with oligo(HBMA) chains. However, the antioxidant activity of Trolox was stabilized for a significantly longer duration (as was the enzyme activity), when Trolox and HBMA were co-localized within a single chain attached to the enzyme.
[0047] Two types of chymotrypsin conjugates were studied to assess the interaction between Trolox and HBMA in the positioning strategy of the present invention. First, chymotrypsin was modified with oligo(HBMA)-COOH and Trolox in a stepwise manner so that the UV-absorber and the antioxidant were attached at separate locations on the enzyme. We designate the chymotrypsin modified at separate positions on the enzyme, “CTM-separate”. In the second conjugate, chymotrypsin was modified with the carboxyl functionalized co-oligomer, ensuring the presence of HBMA and Trolox within a single chain attached to the enzyme. We deisgnate this modified enzyme, “CTM-single”. Schematic representations of the two enzyme-conjugates and their hypothesized stabilizing effects against photooxidation are shown in FIGS. 1A and 1B .
[0048] To assess the impact of co-localization of a UV-absorber and an antioxidant on the stability of the enzyme, first we synthesized a reactive copolymer that included the two stabilizers within a single chain. Trolox was chosen as an antioxidant because of its well known ability to absorb free radicals and the availability of carboxyl group in its structure for covalent modifications. See, for example, Wu, T. W.; Pristupa, Z. B; Zeng, L. H.; Au, J. X.; Wu, J.; Sugiyama, H.; Carey, D. Hepatology 1992, 15, 454-458, the disclosure of which is incorporated herein by reference. We synthesized polymerizable Trolox-HEMA by a condensation reaction between the hydroxyl group in HEMA and the carboxyl group in Trolox. Then, ACV-initiated co-oligomerization of HBMA and Trolox-HEMA was used to obtain an enzyme-reactive low molecular weight product, which was soluble in water-dioxane binary solvent mixtures.
[0049] Oligo(HBMA)-COOH was synthesized as described previously in Lele, B. S.; Russell, A. J. Biomacromolecules 2004, 5, 1947-1955. ESI/APCI mass spectrometric characterization showed the formation of an approximately 60:40 mixture of two oligomers having molecular weights 662 and 772 Da, respectively ( FIG. 2A ). The peak at 772 can be assigned to the dimer of HBMA formed by the oligomerization initiated with C(CH 3 )(CN)—CH 2 —CH 2 —COOH. The peak at 662 can be assigned to the dimer of HBMA formed by the oligomerization initiated with methyl radical, which was probably generated from the decomposition of the initiator. This latter oligomer has no reactive end group and can be filtered out after the enzyme-conjugation reaction. The oligo(HBMA)-COOH mixture was NHS-activated and used to modify chymotrypsin.
[0050] Oligo(HBMA-co-Trolox-HEMA)-COOH was synthesized by ACV-initiated co-oligomerization of HBMA and Trolox-HEMA. Copolymerization of two or more monomers can result in the formation of compositionally different mixtures of individual polymer chains. Surprisingly, the mass spectrum of our co-oligomer showed formation of only one major product having molecular weight of 1190 Da ( FIG. 2 ( b )). Successful co-oligomerization was confirmed from 1 H-NMR spectrum of the product. The Trolox to HBMA ratio was found to be 2:1 from the ratio of the number of protons in the peaks at 2.0 δ (characteristic to —CH 3 substituted phenol moiety in Trolox) and at 7.0-8.0 δ (characteristic to aromatic moiety in HBMA). The co-oligomer was activated with NHS and used to modify chymotrypsin.
[0051] When native chymotrypsin was reacted first with Trolox-NHS ester and purified, we observed via MALDI-TOF formation of a 50/50 mixture of chymotrypsin-Trolox and unmodified chymotrypsin. Interestingly, the reaction of native chymotrypsin with oligo(HBMA)-COONHS always resulted in complete modification of the native enzyme. Therefore, in our conjugate designs, we first modified the enzyme with oligo(HBMA) and then with Trolox.
[0052] As shown in the FIG. 1A , CTM-separate is the conjugate in which chymotrypsin is modified with a UV-absorber and an antioxidant in separate locations. This conjugate was synthesized by stepwise conjugation reactions of native chymotrypsin first with oligo(HBMA)-COONHS and then with Trolox-NHS. MALDI-TOF spectra demonstrate that the first modification of native chymotrypsin increases molecular weight from 25,187 Da to 26,400 Da. Thus, at least 2 molecules of oligo(HBMA) are present on each molecule of the enzyme after the first modification ( FIGS. 3A and 3B ). Repeating the reaction of this modified product with Trolox-NHS increased the molecular weight further to 27,950 Da, representing further modification with 6 more Trolox molecules ( FIG. 3C ). The synthesis of CTM-separate is described in detail in FIG. 4 . Trolox equivalent antioxidant capacity (TEAC) of CTM-separate was found to be 0.3 mM. Thus, as further described in the Experimental section below one third of the original intrinsic antioxidant activity of free Trolox was retained after its conjugation with the enzyme. An ABTS discoloration assay confirmed that neither native chymotrypsin nor chymotrypsin-oligo(HBMA) exhibited antioxidant activity.
[0053] As shown in the FIG. 1B , CTM-single is the conjugate in which chymotrypsin is modified with a single chain comprising both the UV-absorber and the antioxidant. FIG. 4 summarizes the synthetic strategy used to obtain first the single chain oligo(HBMA-co-Trolox-HEMA)-COOH and its conjugate with chymotrypsin (CTM-single). MALDI-TOF spectra showed conjugation of 1-2 chains of the co-oligomer per molecule of native chymotrypsin ( FIG. 3 ( d ); m/z=27,650). CTM-single also retained one third of the original intrinsic antioxidant activity of free Trolox (TEAC=0.33 mM). The modified enzymes retained >90% activity of native chymotrypsin as determined from an end point activity assay of hydrolysis of N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide.
[0054] When an aqueous mixture of chymotrypsin and an excess of water soluble copolymer of Trolox-HEMA and HBMA (M.W. ˜30,000 Da) was exposed to TiO 2 -UV enzyme activity ceased in just 3 hrs. Previously, it has been shown in the chymotrypsin —TiO 2 system, that 80% of the enzyme adsorbs onto TiO 2 within the first two hours of stirring the enzyme-TiO 2 suspension under the conditions used. Lele, B. S.; Russell, A. J. Biomacromolecules 2004, 5, 1947-1955. Thus, excited TiO 2 is always in contact with the enzyme and for a stabilizing agent to be most effective it has to be covalently attached to the enzyme.
[0055] Enzyme stability against photoexcited TiO 2 can also be increased by addition of electron acceptor e.g. oxygen purging and/or hole acceptor e.g. methanol or formic acid. We measured the stability of native chymotrypsin against TiO 2 -UV in the presence of oxygen and 10% v/v methanol, respectively. In both the cases there was a slight increase in enzyme stability, however, this was not significant when compared with the stability of UV and free radical-absorbing CTM-single. Since these additives are not specific to the active site of enzyme bound to TiO 2 it is not surprising that the stabilization was less dramatic.
[0056] FIG. 5A shows the data for activity retention of the modified enzymes synthesized as described above, upon their exposure to TiO 2 -UV. As reported previously, native unprotected chymotrypsin loses all its activity within 3 hrs. The short lag in activity loss is believed to be a result of the non-specific oxidation of the enzyme that occurs before the active site is damaged sufficiently to impair the enzyme activity. The chymotrypisn-oligo(HBMA) with no antioxidant activity had a significantly decreased rate of eventual inactivation, but, importantly, the length of the lag phase was not increased. CTM-separate, however, exhibits an almost doubled inactivation lag phase during exposure to TiO 2 -UV. After the lag phase the rate of inactivation was not slowed. In the case of CTM-single the inactivation lag phase is further increased to four hrs of exposure to TiO 2 -UV. After this marked enhancement in the lag phase stability, the subsequent rate of inactivation was not decreased. Thus, CTM-single exhibited a significantly higher stabilization impact than CTM-separate under photooxidizing conditions.
[0057] In addition to understanding post-modification enzyme activity, it is also desirable to understand whether the intrinsic activity of Trolox was altered by attachment to the protein macromolecule. CTM-separate had 6 molecules of conjugated Trolox and CTM-single had 4 molecules of conjugated Trolox per molecule of the native enzyme. Also, both of the modified enzymes had similar capacities to absorb free radicals (TEAC=0.3 mM). Since Trolox was equally active in each form, though less active than in free solution, the increased enzyme stability that we observed when adding Trolox and HBMA in the same chain must have been caused by co-localization and not changes in Trolox intrinsic activity.
[0058] TiO 2 -UV caused no intrinsic loss in the antioxidant activity of CTM-single ( FIG. 5B ). Interestingly, a 50% loss in antioxidant activity of CTM-separate was observed during exposure to TiO 2 -UV. These results suggest a hypothesis as shown in FIG. 1A that in the absence of adjacent or co-localized HBMA, Trolox is readily degraded by TiO 2 -UV. To investigate further whether the co-localization (for example, single chain) approach is important in protecting Trolox from the photooxidation, we measured the free radical absorbing activity of Trolox exposed to TiO 2 -UV in the free and in the single-chained co-oligomeric form. Data in FIG. 6 showed that free Trolox lost 80% activity during the first hour of photooxidation. However, in the co-oligomeric form, deactivation of Trolox was significantly reduced. A potential mechanism to explain the significant reduction is the UV-absorption by adjacent HBMA and reduction in the excitation of TiO 2 in its vicinity. These data support enhanced enzyme stabilization via a co-localized (for example, single chain) modification approach which enables absorption of free radicals by the antioxidant for a longer duration than that by the separate chain modification approach as shown in FIGS. 1A and 1B .
[0059] Another iportant issue is how TiO 2 -UV inactivates enzyme and how the UV-absorber and antioxidants protect the enzyme. Changes in the secondary structure of proteins during inactivation can be observed by circular dichroism (CD). TiO 2 -UV induces two distinct changes in the secondary structure of native chymotrypsin. Lele, B. S.; Russell, A. J. Biomacromolecules 2004, 5, 1947-1955. FIGS. 7A-7C illustrate CD spectra of native and modified chymotrypsins exhibiting different levels of resistance to changes in the secondary structure caused by TiO 2 -UV for Native chymotrypsin; CTM-separate and CTM-single. respectively. The first change is the perturbation and degradation of tryptophan residues as reflected in the disappearance of the characteristic minimum at 230 nm and the second change is the transition towards random coil formation as reflected in the blue shift in the peak at 202 nm ( FIG. 7A ). After exposure to TiO 2 -UV, CTM-single exhibited minimal changes in its secondary structure ( FIGS. 7B and 7C ). These data show that the prolonged absorption of UV-light and free radicals by the conjugated co-oligomer gave enhanced protection to the enzyme's secondary structure against harmful effects of photooxidation. Studies involving stabilities of glucose oxidase and horseradish peroxidase under TiO 2 -UV irradiation have pointed to the hydroxyl radicals as the main species that inactivates the enzyme. See Ganadu, M. L.; Andreotti, L.; Vitali, I.; Maldotti, A.; Molinari, A.; Mura, G. M. Photochem. Photobiol. Sci. 2002, 1, 951-954 and Hancock-Chen, T.; Scaiano, J. C. J. Photochem. Photobiol. B: Biol. 2000, 57, 193-196. Degradation of tryptophan residues in chymotrypsin by the free radicals generated from TiO 2 -UV have also been described. Lele, B. S.; Russell, A. J. Biomacromolecules 2004, 5, 1947-1955. The co-localization (for example, single chain) modification strategy can remove these radicals effectively since the antioxidant is temporarily protected.
[0060] In summary, representative studies of several embodiments of the present invention demonstrated enhanced the stability of a model enzyme, chymotrypsin, to photooxidation caused by TiO 2 -UV by conjugating the enzyme with oligomeric adducts of UV-absorbing HBMA and free radical absorbing Trolox-HEMA. Without limitation to any mechanism of operation, it is believed that enhanced enzyme stability originates from the ability of HBMA moieties to absorb UV light/energy and reduce the excitation of TiO 2 and thereby protect the antioxidant activity of adjacent Trolox moieties. This allows the representative single-chain-modified enzyme to absorb free radicals for longer without harming the enzyme during photooxidation. Both the antioxidant and the UV-absorber were eventually oxidized by TiO 2 -UV, followed by enzyme deactivatoon. However, the modified enzyme systems studied in the present invention were not optimized. Nonetheless, a stabilization effect of up to 4 hrs was been induced by only two molecules of oligomeric modifiers conjugated to the enzyme. Extended enzyme stability against the photooxidative degradation is, for example, achievable by either increasing the degree of modification or by conjugating high molecular weight copolymers of antioxidant and UV-absorber to the enzyme. Enhancing stability of enzyme against photooxidation is, for example, particularly useful in developing bio-inorganic hybrid materials for decontamination applications. For example, the modified enzyme systems of the present invention can be used in protective coatings that simultaneously use photocatalysis and biocatalysis to decontaminate organophosphates.
Experimental
[0061] Materials: α-Chymotrypsin (from bovine pancreas), N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, sodium deoxycholate, N-hydroxysuccinimide (NHS), sodium phosphate (Na 2 HPO 4 ), bicinchoninic acid solution, copper (II) sulfate solution, bovine serum albumin protein standards, potassium persulfate and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS, 1.8 mM) were purchased from Sigma Co. (Saint Louis, Mo.). HBMA, Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), 2-hydroxyethyl methacrylate (HEMA), 1,3-(dimethylaminopropyl)-3-ethylcarbodiimide.hydrochloride (EDC), 1,3-dicyclohexylcarbodiimide (DCC), 4,4′-azobis(cyanovaleric acid), anhydrous tetrahydrofuran (THF), anhydrous N,N-dimethylformamide (DMF), dichloromethane, n-hexane and dioxane were purchased from Aldrich Chemical Company (Milwaukee, Wis.). Centrifugal dialysis-filtration tubes (Centricon® Plus-20) with 10,000 Da molecular weight cut off (MWCO) were purchased from Millipore Co. (Bedford, Mass.). TiO 2 (Degussa P25) was obtained from Degussa A.G., Frankfurt, Germany.
[0000] Methods
[0062] NMR spectroscopy: 1 H-NMR spectra of oligomeric modifiers were recorded on a Bruker spectrometer operating at 300 MHz.
[0063] ESI-APCI mass spectroscopy: Molecular weights of oligomeric modifiers were determined using Finnigan LCQ quadrupole field ion trap mass spectrometer with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources. Samples were dissolved in dichloromethane (1 mg/mL) and injected into the ionization chamber of the spectrometer.
[0064] MALDI-TOF spectrometry: Modified enzymes were characterized by analyses performed on a Perseptive Biosystems Voyager elite MALDI-TOF. The acceleration voltage was set at 20 kV in a linear mode. Enzyme solution (0.5-1.0 mg/mL) was mixed with an equal volume of matrix (0.5 mL water, 0.5 mL acetonitrile, 2 μL trifluoroacetic acid and 8 mg α-cyano-4-hydroxycinnamic acid) and 2 μL of the resulting mixture were spotted on the plate target. Spectra were recorded after solvent evaporation.
[0065] CD spectroscopy: At 60 min intervals, 0.3 mL aliquots were removed from UV-irradiated enzyme-TiO 2 suspensions and filtered through 0.2 μm filters. Protein solutions were diluted to obtain concentrations of 0.1 mg/mL. 400 μL of the sample (0.1 mg/mL) were placed in a quartz cuvette (path length, 1 mm) inside an Aviv CD spectrometer (model 202). Each spectrum was accumulated by averaging 10 scans between 190 to 260 nm. All spectra were corrected for background signals of the buffer. Mean residual ellipticity ([θ] λ deg.cm 2 .dmol −1 ) values were obtained from θ observed using the equation (1).
[θ] λ =θ observed ·M w /10*( l.c.n )
Where, M w is the molecular weight of chymotrypsin, 1 is the path length (0.1 cm), n is the total number of amino acid residues in chymotrypsin (241) and c is the concentration (g/mL).
[0066] Exposure of enzymes to UV-irradiated TiO 2 : Enzyme (0.8 mg protein/mL, total 10 mL in 25 mM phosphate buffer, pH 7.5) was placed in an open scintillation vial. TiO 2 fine powder (0.25 mg/mL) was added to the protein solution and the suspension was stirred gently at room temperature (25° C.) with a magnetic stir bar placed inside the vial. The enzyme-TiO 2 suspension was placed under a BLAK-RAY® longwave UV lamp (model No. B-100AP, UVP, San Gabriel, Calif.). The distance between the UV lamp and the vial was 18 cm. At this distance, the UV irradiance at 365 nm (λ max ) was 8 mW/cm 2 (determined using a BLAK-RAY® UV meter (Model No. J-221). It was also verified that there was no thermal denaturation of the enzyme during irradiation and the temperature of the enzyme-TiO 2 suspension remained constant (25±2° C.) throughout.
[0067] Determination of the residual enzyme activity: Measurable loss in enzyme activity was observed at 30 min intervals. At 30 min intervals, 100/L aliquots were removed from the irradiated enzyme-TiO 2 suspension and added to 1.2 mL of N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide solution (0.5 mg/mL in 25 mM phosphate buffer, pH 7.5). The enzyme to substrate concentration ratio was 3.4 μM: 800 μM. After 1 min, the TiO 2 -enzyme-substrate suspension was filtered through a 0.2 μm filter and the absorbance of hydrolyzed p-nitroaniline measured at 412 nm using a Perkin-Elmer spectrophotometer (model Lambda 45). Hydrolysis of the substrate by the buffer was negligible during the assay time. Original activities of native and modified chymotrypsins were also determined as described above. It was also confirmed that TiO 2 alone did not cause hydrolysis of the substrate.
[0068] Exposure of antioxidants to UV-irradiated TiO 2 : Trolox (0.01 mg/mL) was dissolved in 10 mL phosphate buffer (25 mM, pH 7.5). TiO 2 (0.25 mg/mL) was added to the Trolox solution. The suspension was stirred and irradiated with UV as described above. At 30 min intervals, 1 mL aliquots were removed from the irradiating suspension and filtered through a 0.2 μm filter. Oligo(HBMA-co-Trolox-HEMA)-COOH (0.03 mg/mL) or a physical mixture of oligo(HBMA)-COOH (0.01 mg/mL) and Trolox (0.02 mg/mL) were dissolved in a 50:50 binary solvent mixture of DMF and phosphate buffer (25 mM, pH 7.5). TiO 2 (0.25 mg/mL) was added to these solutions, irradiated with UV and aliquots filtered as described above.
[0069] Determination of residual antioxidant activity: Antioxidant activities of modified enzymes and the modifiers were measured according to the following modification of the assay reported by Re et al. Re, R.; Pellegrini, N.; Proteggente, A.; Pannala, A.; Yang, M.; Rice-Evans, C. Free Rad. Biol. Med. 1999, 9/10, 1231-1237. This assay is based on the principle of discoloration of pre-formed blue ABTS + radical (λ max 734 nm) due to its quenching by the addition of the antioxidant. Equal volumes of ABTS (1.8 mM) and potassium persulfate (0.63 mM) were mixed together and kept in the dark for 16 hrs at 25° C. to obtain a stable blue colored ABTS + radical. The ABTS + solution was diluted four times to obtain an absorbance of 0.6 at 734 nm. Equal volumes (0.5 mL) of ABTS + and TiO 2 -UV exposed enzyme solution (0.8 mg protein/mL) were mixed together. The change in absorbance at 734 nm was recorded 1 min after the mixing. Similarly, 0.5 mL of TiO 2 -UV exposed Trolox or oligo(HBMA-co-Trolox-HEMA)-COOH solutions were mixed with 0.5 mL of ABTS + and the residual antioxidant activity was then measured. Trolox equivalent antioxidant capacities (TEAC) (defined as the antioxidant activity of 1 mM modified enzyme equivalent to that of the 1 mM free Trolox) were calculated using the standard plot created for the concentration of Trolox versus the change in absorbance of ABTS + .
[0070] Synthesis of 2-methacryloyloxyethyl-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylate) (Trolox-HEMA). In a 500 mL capacity round bottom flask, Trolox (2.5 g, 10 mmol) and HEMA (1.31 g, 10 mmol) were dissolved in 200 mL anhydrous THF. EDC (3.0 g, 15 mmol) was added and the reaction mixture was stirred at 25° C. for 16 hrs. The reaction mixture was filtered to remove urea salts and concentrated to 100 mL under vacuum. The concentrated solution was poured in IL cold water (4° C.). The product precipitated as white powdery material upon standing in the refrigerator for 1 hr and triturating with hexane. The product was washed with water and isolated as a single spot compound (TLC in 80:20 hexane:ethyl acetate). Yield 1 g (27%). 1 H-NMR (CDCl 3 ): 1.5 δ 3H singlet (—C H 3 of chroman ring), 1.75 δ 3H singlet (—C H 3 —C═C— of HEMA), 2.2 δ 9H multiplate (—C H 3 of substituted phenol moiety in Trolox), 2.4 δ 2H triplet (-Ph-CH 2 —C H 2 —C—O— of chroman ring in Trolox), 2.6 δ 2H (-Ph-C H 2 —CH 2 —C—O— of chroman ring in Trolox), 3.9 δ 2H (—O—C H 2 —CH 2 —O—COO— of HEMA), 4.3 δ 2H (—O—CH 2 —C H 2 —O—COO— of HEMA), 5.5 δ singlet 1H (—C═C— H a of HEMA), 6.2 δ singlet 1H (—C═C— H b of HEMA).
[0071] Synthesis of oligo(HBMA-co-Trolox-HEMA)-COOH. In a three necked round bottom flask equipped with a reflux condenser, HBMA (0.88 g, 2.75 mmol), Trolox-HEMA (0.90 g, 2.75 mmol) and 4,4′-azobis(cyanovaleric acid) (0.077 g, 0.275 mmol) were dissolved in 30 mL DMF. Nitrogen gas was purged through the DMF solution for 30 minutes at room temperature. Polymerization was conducted at 80° C. for 12 hrs under the continuous purging of nitrogen. Oligo(HBMA-co-Trolox-HEMA)-COOH was isolated by precipitation of the DMF solution into 1 L distilled water (pH 1.5). The product was purified by first extraction in acetone and then reprecipitation from dichloromethane into n-hexane. Yield 1 g (56%). 1 H-NMR (CDCl 3 ): 0.8 δ singlet (—C H 2 —C—CH 3 of polymer backbone), 1.5-1.7 δ multiplate (—CH 2 —C—C H 3 of polymer backbone), 2.0-2.2 δ multiplate (—C H 3 of substituted phenol moiety in Trolox), 2.5-3.0 δ multiplate (benzyl —C H 2 — of HBMA+Ph-C H 2 —C H 2 — of chroman ring in Trolox), 4.0-4.4 δ multiplate (—COO—C H 2 —C H 2 — of hydroxyethyl spacers in HBMA and Trolox), 7.0-8.3 δ multiplate (aromatic protons of HBMA), 11.2 δ singlet (phenolic-O H of HBMA and Trolox). Molecular weight=1192 (ESI/APCI mass spectrometry).
[0072] Synthesis of oligo(HBMA)-COOH. In a three necked round bottom flask equipped with a reflux condenser, HBMA (4.0 g, 12 mmol) and 4,4′-azobis(cyanovaleric acid) (0.34 g, 1.2 mmol) were dissolved in 40 mL DMF. Nitrogen gas was purged through the DMF solution for 30 minutes at room temperature. Polymerization was conducted at 80° C. for 12 hrs under the continuous purging of nitrogen. Oligo(HBMA)-COOH was isolated by precipitation of the DMF solution into 1 L distilled water (pH 1.5). The product was purified by reprecipitation from dichloromethane into n-hexane. Yield 2 g (50%). 1 H-NMR (CDCl 3 ): 1.0-2.0 δ broad multiplate (—C H 2 —C—C H 3 of polymer backbone), 3.0 δ singlet (benzyl —C H 2 of HBMA), 4.1 δ singlet (—COO—C H 2 —CH 2 —O— of hydroxyethyl spacer in HBMA), 7.0-8.7 δ multiplate (aromatic protons of HBMA), 11.2 δ singlet (phenolic —O H of HBMA). Molecular weight=772 (ESI/APCI mass spectrometry).
[0073] Synthesis of NHS esters. A typical procedure for the synthesis of oligo(HBMA-co-Trolox-HEMA)-COONHS is described in the following. One gram oligo(HBMA-co-Trolox-HEMA)-COOH was dissolved in 20 mL dichloromethane and five fold molar excesses of NHS and DCC were added to the dichloromethane solution. The reaction mixture was stirred for 16 hrs at 25° C. and filtered to remove dicyclohexyl urea. The clear solution was poured into 500 mL n-hexane under stirring to precipitate the product. The product was purified by re-precipitation from dichloromethane into n-hexane. Yield 0.6 g (60%). Trolox-NHS and oligo(HBMA)-COONHS were synthesized in a similar fashion.
[0074] Synthesis of “CTM-single” (chymotrypsin modified with oligo(HBMA-co-Trolox-HEMA). α-Chymotrypsin (100 mg) was dissolved in phosphate buffer (20 mL of 160 mM, pH 8.8) containing 0.8% w/w sodium deoxycholate. Oligo(HBMA-co-Trolox-HEMA)-COONHS (200 mg) was dissolved in anhydrous dioxane (2 mL) and added to the chymotrypsin solution under stirring. The reaction mixture was stirred at 25° C. for 2 hrs and filtered through 0.45 μm filter to remove the precipitated oligo(HBMA-co-Trolox-HEMA)-COOH. The clear solution was lyophilized to remove dioxane. Lyophilized powder containing the enzyme and salts was dissolved in 50 mL phosphate buffer (25 mM, pH 7.5). The enzyme solution was placed in centrifugal dialysis-filtration tubes (Centricon® Plus-20; 10,000 Da MWCO) and centrifuged at 4,000 rpm for 15 minutes. The concentrated retentate was diluted to 20 mL with phosphate buffer (25 mM, pH 7.5) and dial-filtered again as described above. The amount of conjugate obtained was estimated by bicinchoninic acid protein assay. Yield 20-30%.
[0075] Synthesis of “CTM-separate” (chymotrypsin modified with oligo(HBMA) and Trolox). The conjugate was synthesized in two steps. In the first step, α-chymotrypsin (100 mg) was reacted with oligo(HBMA)-COONHS (200 mg). Purified chymotrypsin-oligo(HBMA) (100 mg) was reacted with Trolox-NHS (100 mg) as described above. Yield 20-30%.
[0076] The foregoing description and accompanying drawings set forth the preferred embodiments of the invention at the present time. Various modifications, additions and alternative designs will, of course, become apparent to those skilled in the art in light of the foregoing teachings without departing from the scope of the invention. The scope of the invention is indicated by the following claims rather than by the foregoing description. All changes and variations that fall within the meaning and range of equivalency of the claims are to be embraced within their scope. | A composition includes at least one antioxidant moiety and at least one UV-absorbing moiety. The antioxidant moiety and the UV-absorbing moiety are maintained in proximity to each other. The UV-absorbing moiety and the antioxidant moiety can, for example, be attached to a common entity. The antioxidant moiety and the UV-absorbing moiety can, for example, be covalently attached within a single molecule. The UV-absorbing moiety can be attached sufficiently closely to the antioxidant moiety to enhance the stability of the antioxidant in an environment in which photooxidation can occur. In one embodiment, the UV-absorbing moiety is attached to the molecule to be juxtapositioned to the antioxidant moiety. | 2 |
RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. application Serial No. 09/234,481 filed Jan. 21, 1999 which describes the treatment of indene lithenides with dibromoethane to produce 1,2-bis(indenyl) ethanes.
FIELD OF THE INVENTION
[0002] This invention relates to the synthesis of hydrocarbyl-bridged indenes. More particularly, the invention relates to the synthesis of hydrocarbyl bridged indenes.
Definition
[0003] Hydrocarbyl Bridged Indene—means collectively all isomers of a compound of Formula I:
[0004] wherein “R” is a hydrocarbyl group.
[0005] 1,2-bis(indenyl)ethane or EBI—means collectively all isomers of Formula II:
[0006] in which the symbol “(“indicates a 1,2-bis(indenyl-l)ethane which has a 1,2, 1,2′ double bond (thermodynamic EBI, BRN No. 3055002, CAS RN No. 18657-57-3) or a 2,3 2′, 3′ double bond (kinetic EBI, BRN No. 3083835, CAS RN Nos. 15721-07-0, 18686-04-9, 18686-05-0). atoms are asymmetric when substituted.
[0007] Each of the ring substituents may be hydrogen or any one to ten carbon atom hydrocarbyl group. Each ring substituent may be the same as or different from any other ring substituent. One to ten carbon atom alkyl groups are preferred. 2,2′ methyl and 4,7, 4′7′ dimethyl EBIs are representative.
BACKGROUND OF THE INVENTION
[0008] Meso and rac (racemic) forms of kinetic EBI and thermal isomerization of kinetic to thermodynamic EBI are known phenomena. Maréchal, et al, Bulletin de la Societe Chimique de France (1967) 8:2954-2961.
[0009] Kinetic and thermodynamic EBI are interchangeably useful separately and in mixtures as ligands for metallocene olefin polymerization catalysts. However, the large-scale production of kinetic EBI is constrained because the thermodynamic isomer is produced at temperatures below about −70° C.; whereas, at higher temperatures low yields of kinetic EBI consequent from spiro indene and vinylindene impurities may result. See, e.g., Yang, et al., SYNLETT (1996) 147 and Collins, et al., J. Organometallic Chem. (1988) 342:21 (thermodynamic EBI synthesized at −78° C. stirred overnight and warmed to room temperature). See also Ewen, J., et al., J. Am. Chem. Soc. (1987) 109:6544-6545 and Grossman, R., et al., Organometallics (1991) 10:1501-1505 (50% to 80% recrystallized yields of thermodynamic isomer because of the formation of spiroindene by-product).
SUMMARY OF THE INVENTION
[0010] This invention provides a method for the synthesis of 1,2-bis(indenyl) hydrocarbyl compounds, typically 1,2-bis(indenyl) alkanes. Pursuant to one aspect of the invention, an indenyl lithenide is treated with a terminal dihaloalkane and tetrahydrofuran (THF) wherein a reaction mixture containing a hydrocarbyl bridged indene is produced. The reaction is illustrated by Equation 1:
DESCRIPTION OF THE INVENTION
[0011] In general, the synthesis of hydrocarbyl bridged indenes pursuant to this invention may be accomplished by treating an indenyl alkali metalide compounds of formula XZX, in which Z is any hydrocarbyl and X is any halogen, e.g., chlorine, preferably in a non-interfering medium, preferably diethyl ether and THF.
[0012] Preferably, Z is —(CH 2 ) n —; n=1-20.
[0013] The indenyl alkali metalide is prepared treating indene with an alkali metal alkyl in an ether medium at a temperature of −10 to −20° C. Alkali metal alkyls useful in this invention have the formula MOR, wherein M is any alkali metal and R is an alkyl group, typically a C 1 to C 10 alkyl group. N-butyllithium is preferred.
[0014] The alkali metalide synthesis reaction mixture typically comprises the selected alkali metal alkyl and the ether medium in which it is produced. Hydrocarbyl bridged indenes may be produced by combining a selected terminal dibromoalkane and THF with an appropriate metalide synthesis reaction mixture. Alternatively, the alkali metalide may first be isolated from the reaction mixture in which it is synthesized. According to one embodiment of the invention, the isolated indenide alkali metalide and THF are then reacted with a dibromoalkane, typically at room temperature, wherein a reaction mixture containing a hydrocarbyl bridged indene is produced. No reaction occurs upon combination of the dibromoalkane with the alkali metalide reaction mixture in ethyl ether.
Exemplification of the Invention
EXAMPLE 1 (LABORATORY)
[0015] Indene in diethyl ether (1.25 equivalents) was treated with BuLi in ethyl ether at −20° C. to provide reaction mixture containing lithium indenide pursuant to Equation 2:
[0016] The lithium indenide containing reaction mixture was warmed to room temperature, was stirred for one hour, and then treated 0.5 mol of with dibromoethane. Ten minutes later, THF (0.25 equiv.) was added. The temperature of the reaction slowly warmed to 40° C.
[0017] The 1 H NMR of the product mixture showed >95% yield from indene of the kinetic isomer of EBI. No spiro product was observed. See Equation 3:
[0018] Water was added and the mixture separated into an aqueous phase and an organic phase. The organic phase was separated and dried with sodium sulfate.
[0019] The organic phase solvent (i.e., THF and hexanes) was exchanged with hexanes in an amount such that the final volume was concentrated to about 40 weight % of Kinetic EBI. The solution was cooled to −20° C. and filtered. The solid was dried to give a 35% yield of the kinetic isomer of EBI.
EXAMPLE 2 (PILOT PLANT)
[0020] 23.8 kg of ethyl ether and 4.8 gal (1.25 eq.) of indene are charged to a clean, dry, first reactor. 10.2 kgs of indene are added. The pot temperature of the first reactor was lowered to −20° C. 37.3 kgs of butyllithium in hexanes were fed into the first reactor. The pot temperature was maintained below −10° C. during the feed. The reaction mixture was stirred out overnight at room temperature.
[0021] 16.4 kg (87.3 moles) of dibromoethane was added to the first reactor. Upon completion of the dibromoethane addition, 3.8 kgs of THF were added. An exothermic reaction ensued. The reaction mixture was stirred out with nitrogen sweep.
[0022] 25 kgs of the reactor medium were removed at atmospheric pressure. An equal amount of heptane was added back to the reactor to reach a pot temperature of about 95° C. The reaction mixture was then hot filtered through Celite at a temperature of 75° C. to 80° C. The cake was washed with 10 kgs of heptane, which was stripped to 3 to 4 gallons. The pot temperature was cooled, the reaction mixture filtered, and the product was isolated on a clear Buchner. Dry yield of EBI=6.3 kgs out of Buchner. | A method for treating a terminal dihalo hydrocarbyl compound with an alkali metal indenide to produce a bis(indenyl) hydrocarbyl compound is described. | 2 |
BACKGROUND OF THE INVENTION
The aminoglycoside antibiotics are a well recognized, useful class of antibiotics. One of the most recently recognized aminoglycoside antibiotic families has been the fortimicin family of antibiotics. See U.S. Pat. Nos. 3,976,768 and 3,931,400 which disclose fortimicins A and B.
As with other antibiotics, chemical modification of the fortimicin family of antibiotics has provided useful entities which are either intrinsically more active than the parent antibiotics, have activity against resistant strains of organisms or have reduced toxicity.
Heretofore, it has been necessary to produce fortimicin B and chemically modify that parent antibiotic in order to obtain the desired derivative and this has often required reaction involving numerous, complicated steps.
It has now been found that by converting a suitably protected fortimicin B to the bis-carbamate, and cleaving the glycoside bond to obtain fortamine-bis-carbamate, a number of aminoglycoside antibiotics can be readily prepared simply by reacting the protected fortamine with a suitably protected sugar, in the case of the fortimicins, with a suitably protected purpurosamine as taught in commonly assigned, co-pending U.S. Ser. No. 079,131 filed of even date with the present application.
SUMMARY OF THE DISCLOSURE
2'6'-Di-N-benzyloxycarbonylfortimicin B-1,2:4,5-bis-carbamate and its preparation is disclosed herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention provides the compound 2'6'-di-N-benzyloxycarbonylfortimicin B-1,2:4,5-bis-carbamate. The compound is represented by the formula: ##STR2## wherein R is benzyloxycarbonyl or hydrogen.
The compounds of this invention are useful in the preparation of fortamine-1,2:4,5-bis-carbamate which is useful in the direct synthesis of aminoglycoside antibiotics by glycosidation with a suitably protected sugar moiety such as a purpurosamine as taught in commonly assigned, co-pending application U.S. Ser. No. 079,131 filed of even date herewith.
The preparation of the compound of this invention is summarized in the following reaction scheme and described in detail in the following examples. ##STR3##
The following examples further illustrate the present invention.
EXAMPLE 1
1,2',6'-Tri-N-benzyloxycarbonylfortimicin B(1)
To a stirred solution of 2.0 g of fortimicin B, 30 ml of water and 60 ml of methanol, cooled in an ice bath, is added 4.44 g of N-(benzyloxycarbonyloxy)succinimide. Stirring is continued at 0° for 3 hours and then at room temperature for 22 hours. The major portion of the methanol is evaporated under reduced pressure and the residue is shaken with a mixture of chloroform and water. The chloroform solution is washed with water and dried over anhydrous magnesium sulfate. The chloroform is evaporated and the residue is chromatographed on silica gel. Elution with a solvent system composed of chloroform-methanol-ammonium hydroxide [234:1.4:0.1(v/v/v)] gives 1.05 g of product (1):[α] D 25 -16.5° (c 1.0,Ch 3 OH); IR(CDCl 3 ) 1712 and 1507 cm -1 .
EXAMPLE 2
4-N-Ethoxycarbonyl-1,2',6'-tri-N-benzyloxycarbonylfortimicin B(2)
To a magnetically stirred solution of 3.02 g of 1,2',6'-tri-N-benzyloxycarbonylfortimicin B(1), 130 ml of methanol and 60 ml of a solution of 3.02 g of sodium bicarbonate in 72 ml of water is added 0.90 ml of ethyl chloroformate. Stirring is continued at room temperature for 3 hours. The major portion of the methanol is evaporated under reduced pressure and the residue is shaken with a mixture of 200 ml of chloroform and 200 ml of 5% aqueous sodium bicarbonate. The chloroform solution is separated and washed with 200 ml of water. The aqueous solutions are washed in series with four 100 ml portions of chloroform. The chloroform solutions are combined, and the chloroform is evaporated under reduced pressure leaving 3.36 g of white glass. The latter is chromatographed on 250 g of silica gel packed and eluted with benzene-methanol [95;15(v/v)] to yield 2.57 g of the desired product (2).NMR(CDCl 3 )δ 1.15d(J= 6.4 Hz)(C 6' -CH 3 ); 1.27 t (J=7.2 Hz)(OCH 2 CH 3 ); 3.02(NCH 3 ); 3.43(NCH 3 ); IR(CDCl 3 ) 3555,3437,1707,1658 cm -1 .
EXAMPLE 3
1,2',6'-Tri-N-benzyloxycarbonylfortimicin B-4,5-carbamate (3)
A solution of 13.0 g of 4-N-ethoxycarbonyl-1,2',6'-tri-N-benzyloxycarbonylfortimicin B(2), 5.3 g of sodium bicarbonate and 370 ml of methanol is heated under reflux for 1.5 hours. The methanol is evaporated under reduced pressure and the residue triturated with chloroform. The chloroform suspensions are filtered. Evaporation of the chloroform from the filtrate leaves 12.1 g of product. The latter is chromatographed on 850 g of silica gel using a solvent system prepared from benzene-ethanol [9:1(v/v)] to yield 10.9 g of pure product (3):[α] D 22 +2.5° (c 1%,CH 3 OH); NMR(CDCl 3 )δ 0.98d (J=6.0 Hz)(C 6' --CH 3 ), 2.83(NCH 3 ), 3.44(OCH 3 ); IR(CDCl 3 ) 3562,3438,3320,1759,1706 cm -1 .
EXAMPLE 4
2',6'-Di-N-benzyloxycarbonylfortimicin B-1,2:4,5-bis-carbamate (4)
To a solution prepared from 1.02 g of the compound of Example 3 in 20 ml of dry N,N-dimethylformamide, magnetically stirred, under a nitrogen atmosphere and cooled in an ice bath, is added 0.280 g of 57% oily sodium hydroxide. Stirring is continued for 4 hours with ice bath cooling. Acetic acid (0.8 ml) is then added to the cold suspension. The resulting solution is shaken with a mixture of 100 ml of chloroform and 200 ml of 5% aqueous sodium bicarbonate. The chloroform solution is separated and washed with 200 ml of water. The aqueous solutions are washed in series with three 100-ml portions of chloroform. The chloroform solutions are combined and dried over magnesium sulfate. The chloroform is evaporated under reduced pressure and residual N,N-dimethylformamide is removed by co-distillation with toluene under reduced pressure leaving 1.05 g of a white glass. The latter product (1.01 g) is dissolved in 20 ml of pyridine and 2.0 ml of acetic anhydride is added. The resulting solution is kept at room temperature for 24 hours. The resulting solution is shaken with a mixture of 200 ml of chloroform and 200 ml of 5% aqueous sodium bicarbonate. The chloroform solution is separated and washed with 200 ml of water. The aqueous solution is washed with three 100 ml portions of chloroform. The chloroform solutions are combined and the chloroform is evaporated under reduced pressure. Residual pyridine is removed by co-distillation with toluene under reduced pressure leaving 1.04 g of white glass. The latter (1.01 g) is chromatographed on a column of 100 g of silica gel packed and eluted with a solvent system composed of 1,2-dichloroethane-ethyl acetate [14:16(v/v)]. Initial fractions yield 0.161 g of 1,2',6'-tri-N-benzyloxcarbonyl-2-O-acetylfortimicin B-4,5-carbamate. Further elution of the column yields 0.594 g of a white glass which is rechromatographed on a column of 40 g of silica gel packed and eluted with a solvent system composed of methylene chloride-ethyl acetate [3:2(v/v)] to yield 0.398 g of product (4):[α] D 21 -2.33° (c 1%,CH 3 OH); NMR(CDCl 3 ) δ 1.16d(J=7.0 Hz)(C 6 -CH 3 ); 2.85(NCH 3 ); 3.52(OCH 3 ); IR(CDCl 3 ) 3440,3300, 1750,1697 cm -1 .
EXAMPLE 5
Fortimicin B-1,2:4,5-bis-carbamate dihydrochloride
Five hundred milligrams of the compound of Example 4 in 30 ml of 0.2 N hydrochloric acid in methanol is hydrogenated under 3 atmospheres of hydrogen for 4 hours in the presence of 0.5 g of 5% palladium on carbon. The catalyst is removed by filtration and the methanol is evaporated under reduced pressure. Residual hydrochloric acid is removed by co-distillation with methanol under reduced pressure leaving 371 mg of product as a white glass[α] D 22 +8.8° (c 1%,CH 3 OH); NMR(D 2 O)δ 1.79 (J=7.0 Hz)(C 6' --CH 3 ); 3.35(NCH 3 ); 4.03(OCH 3 ), 5.96d(J=3.7 Hz) (C 1' -H); IR(KBr) 1737,1722 cm -1 . | 2',6'-Di-N-benzyloxycarbonylfortimicin B-1,2:4,5-bis-carbamate and fortimicin B-1,2:4,5-bis-carbamate and its salt are provided by the present invention. The compound is represented by the formula ##STR1## wherein each R is either hydrogen or benzyloxycarbonyl The bis-carbamate is useful as in intermediate in the preparation of fortamine bis-carbamate, which in turn is useful as an intermediate in the preparation of aminoglycoside antibiotics via glycosidation with suitably protected sugar moieties. | 2 |
BACKGROUND
[0001] This application claims priority to JP 2013-140917 filed in Japan on Jul. 4, 2013, the entire disclosure of which is hereby incorporated by reference in its entirety.
[0002] The present invention relates to a method of manufacturing a shield conductor.
[0003] Conventionally, in hybrid vehicles and electric vehicles, a wire harness routed between, for example, a battery and an inverter, or between an inverter and a motor is often inserted in a metallic shield pipe and wired. The shield pipe is arranged beneath a vehicle body floor along a front to rear direction. This shield pipe has a function of shielding an electrical wire and a function of protecting the electrical wire from debris. After being installed inside the engine compartment, the shield pipe is connected with an inverter side via a metallic braid part having flexibility, and is arranged to increase the degree of freedom of the wire harness in a routing direction. The metallic braid part has metallic wire braided in a mesh form, is placed over an end part of the metallic pipe, and is connected typically by caulking with a caulking ring. See, for example, Japanese Patent Application Publication No. 2006-311699.
SUMMARY
[0004] As explained above, the shield pipe and the metallic braid part constitute a shield conductor for the wire harness. The shield pipe and the metallic braid part are typically connected and fixed by caulking with a caulking ring. However, in such a connection method which uses caulking, it is difficult to make the metallic braid part contact an outer peripheral surface of the shield pipe uniformly for the entire periphery, and there is room for improvement with respect to electrical contact reliability. Also, it is to be noted that using a caulking ring increases the number of components.
[0005] Preferred embodiments were made in view of circumstances such as those discussed above and have as an object increasing the reliability, in a shield conductor, of electrical contact between a metallic braid part and a part to be connected.
[0006] A method of manufacturing a shield conductor according to a preferred embodiment by connecting a metallic braid part formed of tubularly braided metallic wire to a part to be connected provided with a tubular part having electrical conductivity includes (i) fitting the metallic braid part to an outer peripheral surface of an end part of the tubular part to form a fitting region; (ii) attaching a metallic welding band formed in a ring shape in the fitting region with the metallic braid part fitted to the end part of the tubular part; (iii) melting the welding band that is attached in the fitting region; and (iv) welding the tubular part to the metallic braid part along a circumferential direction of the tubular part.
[0007] In a preferred embodiment, the metallic braid part and the tubular part can be welded along the circumferential direction by melting the welding band. Therefore, in comparison with the prior art which forms the connection by caulking with a caulking ring, the reliability of electrical contact is high, and a decrease in the number of components can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view showing a periphery of a contact region between a shield pipe and a metallic braid part according to a first embodiment.
[0009] FIGS. 2(A) to (C) are views showing one example of a connection process between a metallic braid part and a shield pipe. FIG. 2(A) is a view showing a state in which a metallic braid part is placed over a shield pipe and a welding band is fitted to a region of the metallic braid part to be welded; FIG. 2(B) is a view showing an intermediate state in which the metallic braid part is being inverted after welding; and FIG. 2(C) is a view showing a state in which the connection operation between the metallic braid part and the shield pipe has been completed.
[0010] FIGS. 3(A) and (B) show a manufacturing method according to a second embodiment. FIG. 3(A) is a view showing a state in which a metallic braid part is placed over a shield pipe and a welding band is fitted to a region of the metallic braid part to be welded; and FIG. 3(B) is a view showing a state in which the connection operation between the metallic braid part and the shield pipe has been completed.
[0011] FIGS. 4(A) and (B) show a manufacturing method according to a third embodiment. FIG. 4(A) is a view showing a state in which a metallic braid part is placed over a shield pipe and a welding band is fitted to a region of the metallic braid part to be welded; and FIG. 4(B) is a view showing a state in which the connection operation between the metallic braid part and the shield pipe has been completed.
DETAILED DESCRIPTION OF EMBODIMENTS
[0012] Preferred embodiments of the present invention will now be explained.
[0013] (1) In a method of manufacturing a shield conductor according to a preferred embodiment, a metallic wire of a metallic braid part may be coated on a surface with copper or copper alloy, a welding band may be fitted to an outer peripheral side of an end part of the metallic braid part prior to welding, and the welding band may be melted in that state using an ultrasonic joining machine so as to connect the metallic braid part with a tubular part.
[0014] A coating is often applied in view of the necessity to prevent corrosion on the surface of the metallic braid part. However, if a coating is applied to the part to be connected, it is generally said that ultrasonic welding will be difficult. Accordingly, there have been problems of poor operational efficiency due to, for example, a need for temporarily removing the coating, performing ultrasonic welding, and thereafter performing an anti-corrosion process in the region where the coating was removed. With regard to this, according to the method described above, the tubular part and the metallic braid part can be joined by melting and fixing the welding band using an ultrasonic joining machine, even without removing the coating.
[0015] (2) A positioning part may be formed for positioning the welding band on the outer peripheral surface of the tubular part, and the welding band may be melted in a state positioned with the metallic braid part disposed between the tubular part and the welding band.
[0016] According to such a method, the welding operation can be done in a state with the welding band appropriately positioned, and thus inconsistencies in the welding region can be avoided.
[0017] Next, first to third embodiments will be described with reference to the drawings.
First Embodiment
[0018] FIG. 1 shows an intermediate routing state of a wire harness WH which can connect, for example, a battery mounted in the rear side of a vehicle interior to an inverter mounted in an engine compartment, in a hybrid vehicle.
[0019] The wire harness WH may be composed of a plurality of electrical wires. During the intermediate routing of the wire harness WH, the wire harness WH may be inserted into an electrically conductive metallic shield pipe 1 (which corresponds to a part to be connected). The shield pipe 1 can be made of aluminum or aluminum alloy, for example, and may be arranged beneath a vehicle body floor.
[0020] After an end part of the shield pipe 1 is installed from beneath the floor into the engine compartment, it may be connected to a metallic braid part 2 . The metallic braid part 2 and the shield pipe 1 together form one example of a shield conductor according to a preferred embodiment. The metallic braid part 2 and the shield pipe 1 are provided across a specified length to the point of connection with the inverter,
[0021] The metallic braid part 2 may be formed, for example, by braiding a copper metallic wire, provided on its surface with a tin coating, for example, in a mesh form and in an elongated tubular form. The wire harness which has been extracted from the shield pipe 1 may be inserted inside this metallic braid part 2 . The end part of the metallic braid part 2 may be connected and fixed to the end part of the shield pipe 1 by a welding method as explained below, and the shield conductor according to a preferred embodiment is thus formed.
[0022] Other than a part of the length of the metallic braid part at a side connected to the shield pipe 1 , the metallic braid part 2 may be inserted into a corrugated tube 3 , and the end part of the metallic braid part 2 may extend to a connection part of the inverter not shown in the drawings. Thus, the wire harness WH may extend for the length of the shield pipe 1 and the metallic braid part 2 , and shielding can be ensured.
[0023] The corrugated tube 3 may be formed, for example, of synthetic resin as a one piece elongated tubular member. A peripheral surface of the corrugated tube 3 may be formed in an accordion shape with repeating convex parts 3 A and concave parts 3 B, and has good flexibility. A grommet G used as a seal may be mounted so as to bridge between this corrugated tube 3 and the shield pipe 1 .
[0024] The grommet G may be formed as a one piece member and may be formed of rubber material (for example, EPDM). A pipe side end part 4 may be formed at one end of this grommet G, and a corrugated side end part 5 may be formed at another end. The pipe side end part 4 and the corrugated side end part 5 may both be formed in a tubular shape. The pipe side end part 4 can have the end part of the shield pipe 1 inserted to its inner side, and the corrugated side end part 5 can pass over an outer peripheral side of the corrugated tube 3 . Outer peripheral surfaces of the pipe side end part 4 and the corrugated side end part 5 may both be secured by, for example, a well-known bonding band, whereby the corrugated side end part 5 may be connected and fixed in a sealed state with respect to the corrugated tube 3 , and the pipe side end part 4 may be connected and fixed in a sealed state with respect to the shield pipe 1 .
[0025] Next, one example of a connection method between the metallic braid part 2 and the shield pipe 1 will be described (see FIGS. 2(A) to (C)).
[0026] First, as shown in FIG. 2(A) , an entire length of the metallic braid part 2 may be placed over the shield pipe 1 along a longitudinal direction. At this time, it is preferable that a terminal end part of the metallic braid part 2 does not protrude from an end surface of the shield pipe 1 in a longitudinally outward direction. The reason for this is to avoid damaging a cover of the electrical wire which forms the wire harness WH by the terminal end of the metallic braid part 2 protruding from the shield pipe 1 .
[0027] In this state, a welding band 7 may be fitted to an outer peripheral surface of the end part of the metallic braid part 2 . The welding band 7 may be formed as a metallic ring, and may have an inner bore that can fit onto the outer peripheral surface of the metallic braid part 2 , while maintaining a small space between the welding band 7 and the outer peripheral surface of the metallic braid part 2 . In this embodiment, the material of the welding band 7 may be copper or copper alloy, for example, but it is possible to use other materials if they provide sufficient joining force relative to the metallic braid part 2 and the shield pipe 1 when melted by an ultrasonic joining machine 8 . Also, the welding band 7 may be formed thin-walled such that it will melt entirely within a specified welding time.
[0028] After completing the attachment of the welding band 7 as described above, the welding band 7 may be set to the ultrasonic joining machine 8 in that condition, and an ultrasonic welding operation is carried out. During this operation, the welding band 7 entirely melts and flows through the mesh of the metallic braid part 2 into a space between the metallic braid part 2 and the shield pipe 1 . Then, after this melted member hardens, the outer peripheral surface side of the shield pipe 1 and the inner peripheral surface side of the metallic braid part 2 are connected to each other via the melted member. Thus, a substantially uniform joining state can be obtained across the entire periphery. In the area shown by W in FIG. 2(B) , a welding region (joining region) 9 may be provided between the metallic braid part 2 and the shield pipe 1 in the lengthwise direction.
[0029] When the welding between the metallic braid part and the shield pipe is completed in this manner, the metallic braid part 2 may be inverted about the welding region 9 so as to be removed from the shield pipe 1 (see FIG. 2(B) ). The connection operation between the shield pipe 1 and the metallic braid part 2 is complete when the metallic braid part 2 is fully removed from the shield pipe 1 (the state shown in FIG. 2(C) ).
[0030] According to the shield conductor of the present embodiment manufactured in the manner described above, even if a caulking ring is not used as in the prior art, it is possible to connect the metallic braid part 2 with the shield pipe 1 by welding across the entire periphery. In contrast to this, even if the metallic braid part 2 and the shield pipe 1 are secured using a caulking ring as in the prior art, the roundness of the caulking ring is not necessarily maintained in the caulking condition, and both members are not attached uniformly across the entire periphery. Thus, there is room for improvement with respect to electrical connection reliability. If the metallic braid part 2 and the shield pipe 1 are ultrasonically welded using the welding band 7 as in the present embodiment, the metallic braid part 2 and the shield pipe 1 can be connected such that they are attached across the entire periphery. Therefore, the reliability of electrical connection can be increased, and inconsistencies in the connection quality can be suppressed. Also, with a caulking ring as in the prior art, the caulking part will be protruding outwardly, and thus there is a need for a space for the grommet G to avoid contacting the caulking part. Due to this arrangement, there is a concern that the grommet G will grow in size, but the present embodiment avoids this and, instead, contributes to a decrease in the size of the grommet G.
[0031] In addition, in the present embodiment as described above, the end part of the metallic braid part 2 may be folded to the inner side such that the terminal end of the metallic braid part 2 does not protrude outwardly. Thus, there is no need to carry out a terminal end process to address any unraveling of the wire terminal end of the metallic braid part 2 . When using ultrasonic welding as in the present embodiment, the welding can be performed on the terminal end of the metallic wire as well, and thus the problem of the metallic wire unraveling does not even arise.
[0032] In addition, a tin coating may be applied to the surface of the metallic wire of the metallic braid part 2 , but as explained above it is difficult to connect a component to which such a tin coating is applied to a part to be connected directly using ultrasonic welding. Therefore, if the metallic braid 2 and the shield pipe 1 are to be ultrasonically welded directly, measures must be taken, such as removing the tin coating of the end part prior to ultrasonic welding, or, at the start, refraining from applying the tin coating to the end part. However, by using the welding band 7 as the joining means as done in the present embodiment, the labor to remove the tin coating and so forth can be omitted, and operational efficiency can be improved.
Second Embodiment
[0033] FIGS. 3(A) and (B) show a manufacturing method according to a second embodiment. In the second embodiment, an annular groove 10 formed as a depression is used for positioning on an outer peripheral surface of an end part of a shield pipe 20 . This annular groove 10 may be formed across the entire periphery of the shield pipe 20 , and may be formed wider than the width of the welding band 7 . Also, although not shown in detail, a split groove may be cut into the welding band 7 along an axial direction, and the welding band 7 can be expanded and returned elastically, with the split groove as a boundary.
[0034] For the process of ultrasonic welding, after placing the metallic braid part 2 over the shield pipe 20 , the welding band 7 may be attached to the metallic braid part 2 (see FIG. 3(A) ). Then, upon positioning the welding band 7 inside the annular groove 10 , due its own elasticity, the welding band 7 can be reduced slightly in diameter and can apply a constricting force to the metallic braid part 2 . Therefore, the welding band 7 is appropriately positioned axially relative to the metallic braid part 2 , and inadvertent misalignment of the metallic braid part 2 can be preemptively avoided during the welding operation. Accordingly, inconsistencies in the joining position of the metallic braid part 2 relative to the shield pipe 20 are avoided, and this contributes to ensuring the joining quality.
[0035] In this manner, upon completion of the ultrasonic joining operation, the welding region 9 of the metallic braid part 2 may be formed in the depressed shape of the annular groove 10 (see FIG. 3(B) ).
[0036] Other structures of this embodiment are similar to those in the first embodiment and produce similar operational effects.
Third Embodiment
[0037] FIGS. 4(A) and (B) show a manufacturing method according to a third embodiment. In this embodiment, a pair of flanges 31 and 31 may be formed on a shield pipe 30 , and the welding band 7 may be positioned between them.
[0038] In other words, the two flanges 31 and 31 may be formed at an end part of the shield pipe 30 , with a specified clearance between the two flanges 31 and 31 in the lengthwise direction, such that they extend along the entire periphery. Both flanges 31 may be formed such that an inner peripheral surface side of the shield pipe 30 is concave and an outer peripheral surface side is protruding. As a result, an annular groove 32 used in positioning is formed on the outer peripheral surface of the shield pipe 30 in a region interposed between the flanges 31 .
[0039] In the third embodiment formed in this manner, it is possible to weld the metallic braid part 2 and the shield pipe 30 using the same method as in the second embodiment. In this case as well, the welding region 9 may be formed in that concave shape inside the annular groove 32 .
Other Embodiments
[0040] The present invention is not limited to the embodiments described in the above explanations and the figures, but embodiments such as the following, for example, are encompassed by the technical scope of this invention.
[0041] (1) In the above described embodiments, a circularly shaped member was used as the welding band 7 , but it would also be suitable to wrap metallic foil around it in a belt-like form. Such a member is encompassed by the welding band 7 of the preferred embodiments.
[0042] (2) In the above described embodiments, the shield pipes 1 , 20 and 30 are shown as parts to be connected to the metallic braid part 2 , but they are not limited to this and could also be, for example, electrically conductive metallic components provided with a tubular part.
[0043] (3) In the above described embodiments, ultrasonic welding is described as a welding process to connect the shield pipe 1 and the metallic braid part 2 , but this can be replaced by resistance welding or soldering or the like.
[0044] (4) Prior to ultrasonic welding, it would be suitable to remove the tin coating from the end part of the metallic braid part 2 , and it also would be suitable to remove the oxide coating from the outer peripheral surfaces of end parts of the shield pipes 1 , 20 and 30 . If this is done, the welding strength can be further increased.
[0045] (5) In the above described embodiments, the shield pipe 1 is shown as the part to which the metallic braid part 2 is to be connected, but this is not limited to pipe components. For example, a component having a connection region like a shield shell that has a tubular part would also be suitable. Also, it is not necessary to form the entire body of the tubular part from a metallic component. For example, the connection surface of the metallic braid part can be formed of electrically conductive metal, and the remainder can be formed of resin.
[0046] (6) In the above described embodiments, the case is described in which a tin coating is applied to the metallic braid part, but it is also suitable to apply other coatings, such as a nickel coating.
[0047] (7) In the above described embodiments, the annular groove 10 is described as being formed as a one piece member to position the welding band 7 on the shield pipe 1 , but it is also suitable to provide a positioning means that is a separate member. Also, the positioning direction is not limited to the longitudinal direction of the shield pipe 1 , and positioning could be done, for example, relative to the circumferential direction. | A method is disclosed for manufacturing a shield conductor by connecting a metallic braid part formed of tubularly braided metallic wire to a part to be connected provided with a tubular part having electrical conductivity. The method includes fitting the metallic braid part to an outer peripheral surface of an end part of the tubular part to form a fitting region; attaching a metallic welding band formed in a ring shape in the fitting region with the metallic braid part fitted to the end part of the tubular part; melting the welding band that is attached in the fitting region; and welding the tubular part to the metallic braid part along a circumferential direction of the tubular part. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Application No. 62/003,281 filed May 27, 2014 having attorney docket number PU140089.
BACKGROUND OF THE INVENTION
[0002] Portable electronic devices are becoming more ubiquitous. These devices, such as mobile phones, music players, cameras, tablets and the like often contain a combination of devices, thus rendering carrying multiple objects redundant. For example, current touch screen mobile phones, such as the Apple iPhone or Samsung Galaxy android phone contain video and still cameras, global positioning navigation system, internet browser, text and telephone, video and music player, and more. These devices are often enabled an multiple networks, such as wifi, wired, and cellular, such as 3G, to transmit and received data.
[0003] The quality of secondary features in portable electronics has been constantly improving. For example, early “camera phones” consisted of low resolution sensors with fixed focus lenses and no flash. Today, many mobile phones include full high definition video capabilities, editing and filtering tools, as well as high definition displays. With this improved capabilities, many users are using these devices as their primary photography devices. Hence, there is a demand for even more improved performance and professional grade embedded photography tools.
[0004] For example, many videos on mobile devices are recorded in a manner where the user may inadvertently rotate the mobile device, thereby tilting the video horizon the vertical orientation of the video for the viewer. In an extreme case, a user may start filming with the camera in a vertical orientation and change to a horizontal orientation. This would result in a video which starts out oriented properly, but ends up rotated 90 degrees when being displayed to a viewer. To correct this problem post processing is required, which is an undesirable option for a user wishing to directly share the video via a social network.
[0005] Additionally, recording a video with the mobile device in a vertical position often results in a video which is taller than it is wide. This end result is not optimal for consumption on most displays, such as television screens, which are typically wider than they are tall. In many cases users shoot video without specific attention to horizontal orientation, especially when filming a social activity, live event or other subject matter where the user is engaged in the experience that takes their focus off the device they are recording with. Further, most mobile phones are designed to be used in a vertical orientation. Thus, a user may start using the device in its intended orientation, only to realize later that video should be filmed in a horizontal orientation.
[0006] Thus, it is desirable to overcome these problems with current video cameras embedded in mobile electronic devices.
SUMMARY OF THE INVENTION
[0007] A method and apparatus for dynamically maintaining a horizontal framing of a video. The system permits the user to freely rotate the device while filming, while visualizing the final output in an overlay on the device viewfinder or screen during shooting. The resulting recording is subsequently corrected to maintain a single orientation with a stable horizon. The system and method is operative display an overlay over a captured representation of the captured video wherein the overlay indicates a modified image with respect to said orientation.
[0008] In one embodiment, the present invention also involves a method of processing a video stream. The method comprises the steps of initializing a video capture mode, receiving data representing a video stream, displaying a representation of said video stream, receiving a data representing an aspect ratio, receiving a data representing rotational position, interpolating an orientation based on the received data representing rotational position, and overlaying a graphic representative of said aspect ratio and said orientation over said representation of said video stream.
[0009] In another embodiment, an apparatus is provided. The apparatus comprises an image sensor, an inertial sensor, a processor, and a memory. The image sensor is for capturing image data having a first orientation. The inertial sensor is for determining rotational values. The processor is for determining a second orientation based on said rotational values received from inertial sensor, interpolating an intermediate orientation based on the first and second orientations, and reorienting said image data from said first orientation to said second orientation through said intermediate orientation. The memory is coupled to the processor and is for storing image data and reorientated image data.
[0010] Another embodiment involves a method of saving image data comprising the steps of receiving data representing a first image having a first orientation, receiving data representing a second orientation indicating a device vertical orientation with respect to gravity, reorienting said first image such that said second orientation becomes a vertical orientation of said first image to generate a reoriented image, wherein the framing of the image is maintained, and saving said reoriented image.
[0011] Another embodiment involves a method of processing a video stream comprising the steps of initializing a video capture mode, receiving a first data representing a video stream, displaying a representation of said video stream, receiving a second data representing an aspect ratio, receiving a third data representing a rotational position, and overlaying a graphic representative of said aspect ratio and said rotational position over said representation of said video stream wherein the framing of video is maintained.
[0012] In another aspect, the present disclosure also involves an apparatus comprising an image sensor for capturing an image data having a first orientation, an inertial sensor for determine a rotational value, a processor for determining a second orientation in response to said rotational value and for reorienting said image data in response to said second orientation while maintaining the framing of the image data to generate a reoriented image having the same framing, and storing said reoriented image.
DETAILED DESCRIPTION OF THE DRAWINGS
[0013] These and other aspects, features and advantages of the present disclosure will be described or become apparent from the following detailed description of the preferred embodiments, which is to be read in connection with the accompanying drawings. In the drawings, wherein like reference numerals denote similar elements throughout the views:
[0014] FIG. 1 shows a block diagram of an exemplary embodiment of mobile electronic device;
[0015] FIG. 2 shows an exemplary mobile device display having an active display according to the present invention;
[0016] FIG. 3 shows an exemplary process for image stabilization and reframing in accordance with the present disclosure;
[0017] FIG. 4 shows an exemplary mobile device display having a capture initialization 400 according to the present invention; and
[0018] FIG. 5 shows an exemplary process for initiating an image or video capture 500 in accordance with the present disclosure.
[0019] FIG. 6 shows and exemplary process for tracking rotation during video capture in accordance with the present disclosure;
[0020] FIG. 7 shows and exemplary process for tracking rotation during image capture in accordance with the present disclosure; and
[0021] FIG. 8 shows and exemplary process for maintaining framing of a shot with rotations during video capture accordance with the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The examples set out herein illustrate preferred embodiments of the invention, and such examples are not to be construed as limiting the scope of the invention in any manner.
[0023] Referring to FIG. 1 , a block diagram of an exemplary embodiment of mobile electronic device is shown. While the depicted mobile electronic device is a mobile phone 100 , the invention may equally be implemented on any number of devices, such as music players, cameras, tablets, global positioning navigation systems etc. A mobile phone typically includes the ability to send and receive phone calls and text messages, interface with the Internet either through the cellular network or a local wireless network, take pictures and videos, play back audio and video content, and run applications such as word processing, programs, or video games. Many mobile phones include GPS and also include a touch screen panel as part of the user interface.
[0024] The mobile phone includes a main processor 150 that is coupled to each of the other major components. The main processor 150 may be a single processor or more than one processor as known by one skilled in the art. The main processor 150 , or processors, routes the information between the various components, such as the network interfaces 110 , 120 , camera 140 , inertial sensor 170 , touch screen 180 , and other input/output I/O interfaces 190 . The main processor 150 also processes audio and video content for play back either directly on the device or on an external device through the audio/video interface. The main processor 150 is operative to control the various sub devices, such as the camera 140 , inertial sensor 170 touch screen 180 , and the USB interface 130 . The main processor 150 is further operative to execute subroutines in the mobile phone used to manipulate data similar to a computer. For example, the main processor may be used to manipulate image files after a photo has been taken by the camera function 140 . These manipulations may include cropping, compression, color and brightness adjustment, and the like.
[0025] The cell network interface 110 is controlled by the main processor 150 and is used to receive and transmit information over a cellular wireless network. This information may be encoded in various formats, such as time division multiple access (TDMA), code division multiple access (CDMA) or Orthogonal frequency-division multiplexing (OFDM). Information is transmitted and received from the device trough the cell network interface 110 . The interface may consist of multiple antennas encoders, demodulators and the like used to encode and decode information into the appropriate formats for transmission. The cell network interface 110 may be used to facilitate voice or text transmissions, or transmit and receive information from the internet. The information may include video, audio, and/or images.
[0026] The wireless network interface 120 , or wifi network interface, is used to transmit and receive information over a wifi network. This information can be encoded in various formats according to different wifi standards, such as 802.11g, 802.11b, 802.11ac and the like. The interface may consist of multiple antennas encoders, demodulators and the like used to encode and decode information into the appropriate formats for transmission and decode information for demodulation. The wifi network interface 120 may be used to facilitate voice or text transmissions, or transmit and receive information from the internet. This information may include video, audio, and/or images.
[0027] The universal serial bus (USB) interface 130 is used to transmit and receive information over a wired link, typically to a computer or other USB enabled device. The USB interface 120 can be used to transmit and receive information, connect to the internet, transmit and receive voice and text calls, etc. Additionally, the wired link may be used to connect the USB enabled device to another network using the mobile devices cell network interface 110 or the wifi network interface 120 . The USB interface 130 can be used by the main processor 150 to send and receive configuration information to a computer.
[0028] A memory 160 , or storage device, may be coupled to the main processor 150 . The memory 160 may be used for storing specific information related to operation of the mobile device and needed by the main processor 150 . The memory 160 may be used for storing audio, video, photos, or other data stored and retrieved by a user.
[0029] The inertial sensor 170 may be a gyroscope, accelerometer, axis orientation sensor, light sensor or the like, which is used to determine a horizontal and/or vertical indication of the position of the mobile device.
[0030] The input output (I/O) interface 190 , includes buttons, a speaker/microphone for use with phone calls, audio recording and playback, or voice activation control. The mobile device may include a touch screen 180 coupled to the main processor 150 through a touch screen controller. The touch screen 180 may be either a single touch or multi touch screen using one or more of a capacitive and resistive touch sensor. The smartphone may also include additional user controls such as but not limited to an on/off button, an activation button, volume controls, ringer controls, and a multi-button keypad or keyboard
[0031] Turning now to FIG. 2 , an exemplary mobile device display having an active display 200 according to the present invention is shown. The exemplary mobile device application is operative for allowing a user to record in any framing and freely rotate their device while shooting, visualizing the final output in an overlay on the device's viewfinder during shooting and ultimately correcting for their orientation in the final output.
[0032] According to the exemplary embodiment, when a user begins shooting the user's current orientation is taken into account and the vector of gravity based on the device's sensors is used to register a horizon. For each possible orientation, such as portrait 210 , where the device's screen and related optical sensor is taller than wide, or landscape 250 , where the device's screen and related optical sensor is wider than tall, an optimal target aspect ratio is chosen. An inset rectangle 225 is inscribed within the overall sensor that is best-fit to the maximum boundaries of the sensor given the desired optimal aspect ratio for the given (current) orientation. The boundaries of the sensor are slightly padded in order to provide ‘breathing room’ for correction. The inset rectangle 225 is transformed to compensate for rotation 220 , 230 , 240 by essentially rotating in the inverse of the device's own rotation, which is sampled from the device's integrated gyroscope. The transformed inner rectangle 225 is inscribed optimally inside the maximum available bounds of the overall sensor minus the padding. Depending on the device's current most orientation, the dimensions of the transformed inner rectangle 225 are adjusted to interpolate between the two optimal aspect ratios, relative to the amount of rotation.
[0033] For example, if the optimal aspect ratio selected for portrait orientation was square (1:1) and the optimal aspect ratio selected for landscape orientation was wide (16:9), the inscribed rectangle would interpolate optimally between 1:1 and 16:9 as it is rotated from one orientation to another. The inscribed rectangle is sampled and then transformed to fit an optimal output dimension. For example, if the optimal output dimension is 4:3 and the sampled rectangle is 1:1, the sampled rectangle would either be aspect filled (fully filling the 1:1 area optically, cropping data as necessary) or aspect fit (fully fitting inside the 1:1 area optically, blacking out any unused area with ‘letter boxing’ or ‘pillar boxing’. In the end the result is a fixed aspect asset where the content framing adjusts based on the dynamically provided aspect ratio during correction. So for example a 16 : 9 video comprised of 1:1 to 16:9 content would oscillate between being optically filled 260 (during 16:9 portions) and fit with pillar boxing 250 (during 1:1 portions).
[0034] Additional refinements whereby the total aggregate of all movement is considered and weighed into the selection of optimal output aspect ratio are in place. For example, if a user records a video that is ‘mostly landscape’ with a minority of portrait content, the output format will be a landscape aspect ratio (pillar boxing the portrait segments). If a user records a video that is mostly portrait the opposite applies (the video will be portrait and fill the output optically, cropping any landscape content that falls outside the bounds of the output rectangle).
[0035] Referring now to FIG. 3 , an exemplary process for image stabilization and reframing 300 in accordance with the present disclosure is shown. The system is initialized in response to the capture mode of the camera being initiated 310 . The initialization may be initiated according to a hardware or software button, or in response to another control signal generated in response to a user action. Once the capture mode of the device is initiated, the mobile device sensor 320 is chosen in response to user selections. User selections may be made through a setting on the touch screen device, through a menu system, or in response to how the button is actuated. For example, a button that is pushed once may select a photo sensor, while a button that is held down continuously may indicate a video sensor. Additionally, holding a button for a predetermined time, such as 3 seconds, may indicate that a video has been selected and video recording on the mobile device will continue until the button is actuated a second time.
[0036] Once the appropriate capture sensor is selected, the system then requests a measurement from an inertial sensor 330 . The inertial sensor may be a gyroscope, accelerometer, axis orientation sensor, light sensor or the like, which is used to determine a horizontal and/or vertical indication of the position of the mobile device. The measurement sensor may send periodic measurements to the controlling processor thereby continuously indicating the vertical and/or horizontal orientation of the mobile device. Thus, as the device is rotated, the controlling processor can continuously update the display and save the video or image in a way which has a continuous consistent horizon.
[0037] After the inertial sensor has returned an indication of the vertical and/or horizontal orientation of the mobile device, the mobile device depicts an inset rectangle on the display indicating the captured orientation of the video or image 340 . As the mobile device is rotated, the system processor continuously synchronizes inset rectangle with the rotational measurement received from the inertial sensor 350 . The representation of the orientation may be checked, further be refined, or improved by analyzing the image using techniques such as line recognition, facial recognition, or the like.
[0038] The user may optionally indicate a preferred final video or image ration, such as 1:1, 9:16, 16:9, or any other ratio selected by the user. The system may also store user selections for different ratios according to orientation of the mobile device. For example, the user may indicate a 1:1 ratio for video recorded in the vertical orientation, but a 16:9 ratio for video recorded in the horizontal orientation. In this instance, the system may continuously or incrementally rescale video 360 as the mobile device is rotated. Thus a video may start out with a 1:1 orientation, but could gradually be rescaled to end in a 16:9 orientation in response to a user rotating from a vertical to horizontal orientation while filming. Optionally, a user may indicate that the beginning or ending orientation determines the final ratio of the video.
[0039] In certain other embodiments, the framing of the image inside the output box is maintained regardless of the aspect ratio. Thus, no matter how the device is oriented, scene is zoomed in or out to keep consistent framing. In some such cases, the object of interest in the video would stay the same size regardless of orientation and aspect ratio. In other cases, where maximum resolution is desired, the zooming in and out may change the size of the object of interest. Alternately, the image may be cropped to maintain the size regardless of orientation and aspect ratio.
[0040] Turning now to FIG. 4 , an exemplary mobile device display having a capture initialization 400 is shown. An exemplary mobile device is show depicting a touch tone display for capturing images or video. According to an aspect of the present invention, the capture mode of the exemplary device may be initiated in response to a number of actions. Any of hardware buttons 410 of the mobile device may be depressed to initiate the capture sequence. Alternatively, a software button 420 may be activated through the touch screen to initiate the capture sequence. The software button 420 may be overlaid on the image 430 displayed on the touch screen. The image 430 acts as a viewfinder indicating the current image being captured by the image sensor. An inscribed rectangle 440 , as described previously, may also be overlaid on the image to indicate an aspect ratio of the image or video to be captured.
[0041] Referring now to FIG. 5 , an exemplary process for initiating an image or video capture 500 in accordance with the present disclosure is shown. Once the imaging software has been initiated, the system waits for an indication to initiate image capture. Once the image capture indication has been received by the main processor 510 , the device begins to save the data sent from the image sensor 520 . In addition, the system initiates a timer. The system then continues to capture data from the image sensor as video data. In response to a second indication from the capture indication, indicating that capture has been ceased 530 , the system stops saving data from the image sensor and stops the timer.
[0042] The system then compares the timer value to a predetermined time threshold 540 . The predetermined time threshold may be a default value determined by the software provider, such as 1 second for example, or it may be a configurable setting determined by a user. If the timer value is less than the predetermined threshold 540 , the system determines that a still image was desired and saves 560 the first frame of the video capture as a still image in a still image format, such as jpeg or the like. The system may optionally chose another frame as the still image. If the timer value is greater than the predetermined threshold 540 , the system determines that a video capture was desired. The system then saves 550 the capture data as a video file in a video file format, such as mpeg or the like. The system may then return to the initialization mode, waiting for the capture mode to be initiated again. If the mobile device is equipped with different sensors for still image capture and video capture, the system may optionally save a still image from the still image sensor and start saving capture data from the video image sensor. When the timer value is compared to the predetermined time threshold, the desired data is saved, while the unwanted data is not saved. For example, if the timer value exceeds the threshold time value, the video data is saved and the image data is discarded.
[0043] One potential issue that may be encountered is that the measurements from the inertial sensor and the times stamps of the video or still image may not be ideally synchronized. For example, the period for updated positional or rotational measurements and/or data may be too infrequent for the capture of video or images resulting in an inaccurate orientation for the video or image. This can result in choppy looking video. To address this positional or rotational data can be interpolated to determine an intermediate orientation. An example of this can be seen in FIGS. 6 and 7 .
[0044] FIG. 6 depicts a flow diagram 600 of an exemplary methodology for processing a video stream wherein rotation occurs during capture. At the most basic level, the methodology involves seven steps. The first step is initiating capture of a video stream (step 610 ). The next step is receiving data representing a video stream (step 620 ). A representation of the video stream can then be displayed (step 630 ). The fourth step is receiving data representing an aspect ratio (step 640 ). The fifth step is receiving data representing rotational position (step 650 ). The orientation can then be interpolated using the data representing rotational position (step 660 ) The last step of the basic method is overlaying a graphic representative of said aspect ratio and said orientation over said representation of said video stream (step 670 ).
[0045] FIG. 7 depicts a flow diagram 700 of an exemplary methodology for processing a still image wherein rotation occurs during capture. At the most basic level, the methodology involves seven steps. The first step is initializing a capture mode (step 710 ). The next step is receiving data representing an image (step 720 ). During capture data representing rotational position is received (step 730 ). The capture is then deactivated (step 740 ). The orientation can then be interpolated using the data representing rotational position (step 750 ). Once orientation is interpolated, the image can be rotated accordingly (step 760 ) The last step of the basic method is saving the rotated image (step 770 ).
[0046] In some embodiments positional or rotational measurements can be obtained at the beginning and end of capture and the intermediate orientation can be interpolated. Such interpolation can further include the time stamp information of the video to more accurately orientate the video in accordance with time. Other techniques such as running average velocity can also be used to refine the interpolation. Other estimation techniques can also be used. In other embodiments, the frequency of rotational measurements may be increased during video capture to provide more accurate positional information in time with the video.
[0047] In certain other embodiments, the framing of the image inside the output box is maintained regardless of the aspect ratio. Thus, no matter how the device is oriented, scene is zoomed in or out to keep consistent framing. An example of this can be seen in FIG. 8 .
[0048] FIG. 8 depicts a flow diagram 800 of an exemplary methodology for processing a video stream wherein rotation occurs during capture. At the most basic level, the methodology involves six steps. The first step is initiating capture of a video stream (step 610 ). The next step is receiving data representing a video stream (step 820 ). A representation of the video stream can then be displayed (step 830 ). The fourth step is receiving data representing an aspect ratio (step 840 ). The fifth step is receiving data representing rotational position (step 850 ). The last step of the basic method is overlaying a graphic representative of said aspect ratio and said orientation over said representation of said video stream wherein the framing of the original video is maintained in the overly (step 860 ).
[0049] In some embodiments, the object of interest or subject in the video would stay the same size regardless of orientation and aspect ratio. In other embodiments, where maximum resolution is desired, the zooming in and out may change the size of the object of interest. Alternately, the image may be cropped to maintain the size regardless of orientation and aspect ratio.
[0050] It should be understood that the elements shown and discussed above, may be implemented in various forms of hardware, software or combinations thereof. Preferably, these elements are implemented in a combination of hardware and software on one or more appropriately programmed general-purpose devices, which may include a processor, memory and input/output interfaces. The present description illustrates the principles of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope. All examples and conditional language recited herein are intended for informational purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herewith represent conceptual views of illustrative circuitry embodying the principles of the disclosure. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudocode, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. | A method and apparatus for dynamically maintaining a horizontal framing of a video. The system permits the user to freely rotate the device while filming, while visualizing the final output in an overly on the device viewfinder or screen during shooting. The resulting recording is subsequently corrected to maintain a single orientation with a stable horizon. The system and method is operative display an overly over a captured representation of the captured video wherein the overlay indicates a modified image with respect to said orientation | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to apparatus, commonly referred to as retrievers, used in removing and installing plungers in the well head of a hydrocarbon producing well. More specifically the invention relates to such apparatus that employ a magnetic latching mechanism for engaging the plunger in both removing the plunger from a well and replacing a plunger in a well.
2. State of the Art
A plunger lift is an apparatus that is used commonly in the oil and gas industry to increase the productivity of oil and gas wells. Descriptions of the use of such plunger lifts are well described in the following U.S. Pat. Nos. 2,661,024; 6,719,060; 6,935,427; and 7,383,878. As explained in these patents, a plunger is designed to intermittently drop to the bottom of a well and then rise to the top carrying well liquids out of the well that would otherwise collect at the bottom of the well and thus decrease the efficiency of the operation of the well.
When the plunger rises to the top of the well it is retained in a receiver near the well head until it is to be dropped back down the well. The receiver is also commonly called a lubricator. The plunger requires recurrent maintenance and periodic replacement which requires that the plunger be repeatedly removed from the receiver or lubricator. This is done by taking a cap off the well head and using a retriever apparatus to reach down into the receiver or lubricator and retrieve the plunger through the open end of the well head.
Retrievers have been used that employ different mechanical means to attach to the upper end of the plunger in able to pull the plunger up and out of the well head. These mechanical connectors often employ collets, fingers or other projections that catch an engagement means on the upper end of the plunger. The retrievers are carried from well to well in the back of a truck of the person servicing the well, and the collets, fingers or other projections are subject to being broken and bent to where they are unusable. Further dirt and grime can accumulate in the fingers and projections again rendering them inoperable at least until they are thoroughly cleaned.
A retriever has been used that employs a magnetic connection between the distal end of the retriever and the plunger. In FIG. 1 there is shown a longitudinal cross-sectional view through such a retriever that is currently being used and which uses a magnetic connection with the plunger. As shown in FIG. 1 , the prior art retriever comprises an elongate, solid handle 10 that is cylindrical in shape, i.e., has a round transverse cross-section. The handle 10 is made of aluminum. A block 11 of polymeric material such as polyethylene is press fit onto the distal end of the handle 10 . A bore 12 is formed inwardly from the distal end of the block 11 , and a magnet 13 is received in that bore 12 . The magnet 13 is itself press fit into a brass ring 14 , which in turn is press fit into a steel ring 15 , with the assembled magnet 13 , and rings 14 and 15 being press fit as a unit into the bore 12 of the block 11 at the distal end of the handle 10 . A series of grooves 16 are formed near the proximal end of the handle 10 as means for firmly grasping the handle 10 .
In the device of the prior art as shown in FIG. 1 , the face 18 of the magnet 13 is exposed and subject to being impacted at its exposed face by other tools and so forth as it is being transported in the bed of a truck from one well to another. The magnet 13 is very brittle and subject to being broken by such impacts on the exposed face 18 of the magnet 13 . To minimize impact of the magnet 13 with the plunger when the retriever is being used, the block 11 is provided with a circular, projecting lip 17 from the face 18 of the magnet 13 at the perimeter of the block 11 .
In use, that lip 17 can be worn away or broken away which can result in the plunger impacting the magnet 13 when the retriever is lowered into the well head to retrieve the plunger. Again, the magnet 13 is very brittle and it is imperative that the magnet 13 is not chipped or broken such that pieces of the magnet 13 get dropped into the well. Thus, care must be exercised to insure that there has been no damage to the lip 17 whenever the retriever is used.
When the lip 17 is in proper, undamaged condition, the stand-off space created between the plunger and the magnet 13 by the lip 17 decreases the lifting power of the retriever. Another problem associated with the existing magnet retriever is its inability to readily let go of the plunger when inserting the plunger through the well head into the receiver of the well. The magnetic retriever of the prior art as shown in FIG. 1 has to be vigorously shaken to disengage the plunger from the magnetic connection. That risks damaging the plunger and the receiver or lubricator of the well when the plunger drops when it breaks magnetic connection to the retriever.
SUMMARY OF THE INVENTION
In accordance with this invention, an improvement is made in a retriever device using a magnetic connection between the retriever and the plunger. The improved magnetic retriever device is used for alternatively removing and installing a plunger in a receiver located at the well head of a hydrocarbon producing well, and the invention also includes a novel method of using the retriever to install a plunger in the receiver of the well.
The device of the present invention comprises a straight, elongate, rigid member having a metallic mounting block integrally attached to a distal end of the rigid member. The proximal end of the mounting block is attached to the distal end of the rigid member, and the mounting block further has a proximal end, with a side wall connecting the distal and proximal ends thereof. The mounting block has a bore that extends inwardly from its distal end, and a magnet is fit snugly in the bore in the mounting block.
A metallic cup member is provided for securely retaining the magnet within the bore of the mounting block as well as to provide a means of preventing impacts of any object directly against the otherwise open face of the magnet. There is no chance that pieces of the magnet can be chipped off or broken therefrom and fall into the well. The cup has a side wall that extends from the perimeter of an end wall, whereby the side wall forms an otherwise open end of the cup member. The otherwise open end of the cup is press fit over the distal end of the mounting block.
To achieve a secure, tight press fit of the side wall of the cup member with the distal end of the mounting block, the side wall of the cup member has an internal face that has a circumferential shape corresponding to an outer circumferential shape of the side wall of the mounting block. In addition, the internal face of the side wall of the cup member has a circumferential dimension that is slightly less than corresponding circumferential dimension of the side wall of the mounting block, so that the side wall of the cup member makes a tight, secure, press fit around the side wall of the mounting block. The magnet is thus permanently retained tightly in the bore of the mounting block.
The rigid member, the mounting block and the cup member, of course, have circumferential dimensions that will allow the retriever device to be inserted longitudinally into the well head and receiver of the well.
In preferred embodiments of the invention novel means are provided for easy, reliable disengagement of the plunger from the magnet when the plunger is being installed in the receiver of the well head. In those embodiments, a mechanical disengagement of the plunger is achieved that does not involve shaking or other sudden movement of the retriever to disengage the plunger from the magnetic connection at the end of the retriever. In the preferred embodiments, a longitudinal, central bore is provided from the proximal end of the rigid member to the distal end thereof.
A push rod is positioned in the continuous bore of the retriever device for longitudinal movement back and forth in that continuous bore. The push rod has its proximal end extending from the proximal end of the rigid member of the retriever device. Means are provided for restricting the longitudinal movement of the push rod back and forth inside the rigid member, and the lower end portion of the push rod is further mechanically linked to appropriate mechanical means for disengaging the plunger from the magnet and thereby readily and safely releasing the plunger from the magnet on the retriever device when the plunger is being installed in its proper place in the receiver or lubricator of the well.
In installing a plunger into the well, the distal end of the push rod is contained within the bore of the retriever, and the plunger is attached at its upper end to the magnet on the distal end of the retriever device. The plunger and retriever are introduced longitudinally into the well through the well head until the plunger is in its desired position in the receiver or lubricator. At that point, the push rod and rigid member are moved relative to each other so as to activate the means for disengaging the plunger from the magnet at the end of the retriever device. The plunger is thus gently but firmly released from its magnetic connection to the retriever device, and there is no chance of the plunger being dropped into the receiver or lubricator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (prior art) is a longitudinal cross-sectional view of a prior art retriever device that utilizes a magnet to attach the plunger to the distal end of the retriever;
FIG. 2 is a longitudinal cross-sectional view of an improved magnetic retriever in accordance with the present invention;
FIGS. 3 through 7 are partial longitudinal cross-sectional views of five similar but slightly different embodiments of the retriever in accordance with the present invention, with the cross-sectional views being taken along line 3 - 3 of FIG. 2 ; and
FIGS. 7 and 8 are a cross-sectional views taken along line 7 - 7 of FIG. 2 , line 8 - 8 of FIG. 5 , respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various preferred embodiments of the retriever device of the present invention for alternatively removing and installing a plunger in a receiver located at the well head of a hydrocarbon producing well in accordance with the present invention are shown in FIGS. 2 through 8 of the drawings. In the drawings, the same reference numbers designate the same elements having the same basic functions in each of the various embodiments.
As illustrated, the device comprises a straight, elongate, rigid, cylindrical tube 20 having a round exterior periphery, and a longitudinal opening 21 extends from a proximal end 23 of the rigid tube 20 to a distal end 22 of that tube 20 . A metallic mounting block 24 , having a distal end 25 and a proximal end 26 , is securely attached at its proximal end 26 to the distal end 22 of the rigid tube 20 by appropriate means that will be described in more detail hereinafter. A cylindrical side wall 27 forms the outer periphery of the mounting block 24 , with the side wall 27 extending between the distal end 25 and proximal end 26 of the mounting block 24 .
A first bore 29 extends inwardly from a distal end 25 of the mounting block 24 . The bore 29 is, of course, circular in shape, and any reference to a bore in this specification will also be one having a circular shape. The center axis of the first bore 29 is in substantially longitudinal alignment with a center axis of the longitudinal opening 21 in the rigid tube 20 .
The circular-shaped first bore 29 forms a cavity which receives a circular-shaped magnet 30 therein. The magnet 30 has a substantially circular perimeter that is received snugly in the first bore 29 , with the inner face of the magnet 30 abutting the inner end of the first bore 29 . The magnet 30 is sized such that it is received in its entirety within the first bore 29 .
A second bore 31 extends inwardly from a proximal end 26 of the mounting block 24 . The second bore 31 is in substantially longitudinal alignment with the center axis of the longitudinal opening 21 in the rigid tube 20 . The second bore 31 extends inwardly to meet with and join the first bore 29 , so that an inner end of the second bore 31 opens into the inner end of the first bore 29 . The magnet 30 retained in the first bore 29 abuts the inner end of the second bore 31 . A third bore 32 extends through magnet 30 , with the third bore 32 being in substantially longitudinal alignment with the longitudinal opening 21 in the rigid tube 20 . The third bore 32 is also in substantially longitudinal alignment with the first and second bores 29 and 31 of the mounting block 24 .
A metallic cup member 33 is provided to encapsulate the perimeter sides and distal end of the mounting block 24 . The metallic cup member 33 has a substantially planar end wall 34 , with a peripheral side wall 35 extending from the perimeter of the end wall 34 in a direction substantially perpendicular to the end wall 34 . The free, distal end of the side wall 35 terminates in an otherwise open end of the cup member 33 facing away from the substantially planar end wall 34 of the cup member 33 . A central opening 38 having a substantially circular shape is provided in the planar end wall 34 of the cup member 33 . The central opening 38 has a diameter that is at least the same as the diameter of the third bore 32 in the magnet 30 . Preferably, the diameters of the central opening 38 and the third bore 32 are substantially identical, with the central opening 38 and the third bore 32 being in substantially coaxial alignment so that adjacent peripheral edges of the third bore 32 and the central opening 38 lie in abutting, side-by-side relationship with each other. Accordingly, the central opening 38 opens directly into the third bore 32 .
The peripheral side wall 35 of the cup member 33 has an internal face that has a circumferential shape corresponding to an outer circumferential shape of the outer side wall 27 of the mounting block 24 . The internal surface of the peripheral side wall 35 of the cup member 33 has a circumferential dimension that is slightly less than the corresponding circumferential dimension of the outer side wall 27 of the mounting block 24 . Preferably, the circumferential dimension of the internal surface of the side wall 35 of the cup member 33 is between about 0.004% and 0.0045% less than the corresponding circumferential dimension of the side wall 27 of said mounting block 24 . The side wall of the cup member 33 is press fit around the outer side wall 27 of the mounting block 24 thereby permanently retaining the magnet tightly in the first bore 29 of the mounting block 24 .
A straight, elongate rod 36 is positioned for longitudinal movement in the rigid tube 20 . The rod 36 has a proximal end 37 that projects outwardly from the proximal end 23 of the rigid tube 20 . Means are provided for restraining the longitudinal movement of the rod 36 in the rigid tube 20 so that when the proximal end 37 of the rod 36 moves toward the proximal end 23 of the rigid tube 20 , the distal end 39 of the rod 36 moves from a first position in which it is located at least inwardly of an outer face of the planar end wall 34 of the cup member 33 to a second position extending outwardly by at least about 1 cm from said outer face of the planar end wall 34 of the cup member 33 .
The means for restraining the longitudinal movement of the rod 36 advantageously comprises a relatively short slot 41 that is formed in the side wall of the rigid tube 20 as shown in FIGS. 2 and 7 . The center axis of slot 41 is substantially parallel with a center axis of the longitudinal opening 21 in the rigid tube 20 . A transverse opening 42 (see FIG. 7 ) extends substantially diametrically into the rod 36 . A pin 43 is received in the transverse opening 42 , with an outer end of the pin 43 projecting outwardly from the transverse opening 42 into the slot 41 in the rigid tube 20 . The longitudinal movement of the rod 36 is thus restrained to the movement of the pin 43 back and forth in the slot 41 .
Means are also provided for returning the rod 36 from its second position back to its first position. In one embodiment, a knob 46 is attached at the proximal end of the rod 36 , with the knob 46 having a peripheral dimension that is greater than a corresponding peripheral dimension of the rod 36 . A coil spring 47 is positioned around the distal end of the rod 36 , with the spring 47 being located between the proximal end 23 of the rigid tube 20 and the knob 46 . Coil spring 47 biases the rod 36 to automatically return it to its first position when there is no downward force applied to the rod 36 .
In a second embodiment of means for returning the rod 36 from its second position to its first position, the actual movement of the rod 36 is done manually rather than being biased by a spring, and means are provided for selectively holding the rod 36 in its second position. In the second embodiment, a side notch 44 can be formed to extend from an end of the slot 41 as shown in FIGS. 2 and 7 . The side notch 44 projects substantially transverse of the slot 41 at the end of the slot 41 that is closest to the distal end 22 of rigid tube 20 . The side notch 44 forms a detente into which the pin 43 can be positioned to retain the rod 36 in its first position. The rod 36 is moved so that the pin 43 is positioned adjacent to the side notch 44 , and then the rod 36 is rotated so that the pin 43 moves into the side notch 44 .
It should be recognized that the notch 44 would be superfluous and not necessary when a coil spring 47 is employed as described above. Vice versa, the coil spring 47 would not be necessary when the notch 44 is used.
The rigid tube 20 , the mounting block 24 and the cup member 33 all have circumferential dimensions that will allow the mounting block 24 , the cup member 33 and the rigid tube 20 to be inserted longitudinally into the receiver of a well head of a hydrocarbon producing well.
As mentioned previously, means are provided for attaching the proximal end 26 of the mounting block 24 to the distal end 22 of the rigid tube 20 . Two preferred embodiments of such means are disclosed. In the first embodiment as illustrated in FIG. 3 , the second bore 31 in the mounting block 24 is, of course, cylindrical in shape, and it is provided with internal threads. The distal end 22 of the rigid tube 20 has a cylindrical peripheral shape, and the distal end 22 is provided with external threads that engage the internal threads in the second bore 31 of the mounting block 24 . In this embodiment, the distal end 22 of the rigid tube 20 is threaded completely through the second bore 31 such that the distal end 22 extends to approach but not contact an inner face of the magnet 30 .
In the second embodiment as illustrated in FIG. 4 a counter bore 50 extends inwardly around and along the second bore 31 in the mounting block 24 from the proximal end 26 of the mounting block 24 . The counter bore 50 is, of course, cylindrical in shape, and it is provided with internal threads. The distal end 22 of the rigid tube 20 has a cylindrical peripheral shape, and the distal end 22 is provided with external threads that engage the internal threads in the counter bore 50 of the mounting block 24 . In this embodiment, the counter bore 50 does not extend along the entire length of the second bore 31 , and the distal end 22 of the rigid tube 20 is threaded into the counter bore 50 so that it is firmly and securely held in the counter bore 50 .
In all embodiments of the invention, the rigid tube 20 is preferably made of aluminum, the mounting block 24 is preferably made of carbon steel, and the cup member 33 and the rod 36 are both preferably made of stainless steel. Further, means can be provided for firmly grasping the proximal end 23 of the rigid tube 20 . Although not shown in the drawings, the means for grasping the rigid tube 20 can be a series of spaced apart, peripheral indentations formed at the proximal end 23 of the rigid tube 20 in a very similar manner to the series of grooves 16 of the prior art retriever shown in FIG. 1 .
The embodiments of the invention as described heretofore are advantageously used when removing and installing plungers that have a relatively solid upper surface. In using the retriever of such embodiments to remove a plunger from a well head, the distal end 22 of the tube 20 and its associated mounting block 24 and magnet 30 is inserted longitudinally into the well head until the cup member 33 and magnet 30 contact the upper end of the plunger. The tube 20 is then pulled from the well head, and the plunger is readily detached from its magnetic attachment to the magnet 30 .
When using the retriever as described heretofore to install a plunger in a receiver located at the well head of a hydrocarbon producing well, the upper end of a plunger is magnetically attached to the cup member 33 and magnet 30 , and the plunger and tube 20 are inserted longitudinally into the well head to position the plunger at a desired position in the receiver at the well head. Then, the proximal end 23 of the rod 20 is pushed downwardly while simultaneously pulling upward on an proximal end 23 of the rigid tube 20 to gently release the plunger from magnetic attachment with the magnet 30 . The tube 20 , with the magnet 30 and the rod 36 are then withdrawn from the well head.
Alternative, preferred embodiments of the invention are used when the plunger is of a construction that has an opening located in the center of the plunger. In that situation, the distal end 37 of the rod 36 as shown in the embodiments of FIGS. 2-4 would not contact the plunger as the rod 36 is moved to its second position extending from the exposed face of the planar end wall 34 of the cup member 33 . One of the alternative embodiments is shown in FIG. 5 .
In the embodiment illustrated in FIG. 5 , the rigid tube 20 , longitudinal opening 21 , the elongate rod 36 , the mounting block 24 , the magnet 30 and the cup member 33 are all basically the same, with substantially the same functions, as the like numbered elements of the embodiments of FIGS. 2-4 . The means for restraining the longitudinal movement of the rod 36 , i.e., the slot 41 , the pin 43 and the opening 42 in the rod 36 have the same functions as the same numbered elements of the embodiments as shown in FIGS. 2-4 , but have been relocated to a position near the distal end 22 of rigid tube 20 and the distal end 39 of the rod 36 .
When the rod 36 moves downwardly, a distal end 39 of the rod 36 moves from a first position in which it is spaced inwardly by at least about 1 cm from the proximal end 26 of the mounting block 24 to a second position in which the distal end 39 of the rod 36 at least approaches the proximal end 26 of the mounting block 24 .
A disengagement member is provided that comprises a base member 53 that has a central orifice 54 extending there through so that the orifice 54 encircles the rigid tube 20 whereby the base member 53 can move back and forth longitudinally along the rigid tube 20 . A skirt 55 extends from a periphery of the base member 53 so that the skirt 55 surrounds the cup member 33 and can move smoothly back and forth over the surface of the cup member 33 as the base member 53 moves longitudinally back and forth along the rigid tube 20 .
Means are associated with the distal end 39 of the rod 36 for moving the disengagement member. Such means comprises positioning the slot 41 near the distal end 22 of the rigid tube 20 , with the pin 43 extending through the slot 41 in the rigid tube 20 so that the pin 43 projects outwardly from an outer surface of the rigid tube 20 and engages a substantially round receiver opening 56 that is provided extending substantially axially into the base member 53 from the orifice 54 in the base member 53 . The pin 43 is received securely in the receiver opening 56 in the base member 53 so that the base member 53 moves back and forth as the pin 43 moves back and forth in the slot 41 .
When the distal end 39 of the rod 36 moves toward the distal end 22 of the rigid tube 20 , a distal, exposed end 57 of the skirt 55 projects outwardly away from the outer face of the planar end wall 34 of the cup member 33 . Thereafter, when the distal end 39 of the rod 36 moves back away from the distal end 22 of the rigid tube 20 , the skirt 55 retracts back over the sidewall 35 of cup member 33 so that the exposed end 57 of the skirt 55 does not project from the outer face of the planar end wall 34 of cup member 33 .
Although not shown explicitly in FIG. 5 , it is to be recognized that the magnet 30 of FIG. 5 could be provided with a bore 32 as shown in the embodiments of FIGS. 2-4 , and the planar end wall 35 of FIG. 5 could be provided with a central opening 38 as shown in FIGS. 2-4 . The distal end 39 of the rod could be extended down into the bore in the magnet so that the distal end 39 projects out through the opening in the cup member 33 when the skirt 55 projects outwardly away from the outer face of the planar end wall 34 of the cup member 33 .
The embodiment of the invention shown in FIG. 5 can be modified slightly as shown in FIG. 6 . In the embodiment shown in FIG. 6 , the rod 36 extends through the rigid tube 20 as in the other embodiments of the invention that have previously been described. But, in the embodiment shown in FIG. 6 , the distal end 39 of the rod 36 is securely attached to the proximal end 26 of the mounting block 24 . As shown in FIG. 6 , the end 39 is provided with external threads which are received in a threaded bore 60 in the proximal end 26 of the mounting block 24 . The magnet 30 is encapsulated in the mounting block 24 by cup member 33 in the same manner as previously described herein.
In the embodiment shown in FIG. 6 , the distal end 22 of the rigid tube 20 is securely attached to the base member 53 of the disengagement member. The orifice 54 of the base member 53 encircles the rod 36 as described hereinbefore with respect to the embodiment illustrated in FIG. 5 . The skirt 55 of the disengagement member extends from the periphery of the base member 53 as previously described with respect to the embodiment illustrated in FIG. 5 . Means for restricting movement of the rod 36 within the rigid tube 20 comprises the short slot 41 in rigid tube 20 . A pin receiving opening 42 is provided in rod 36 , and a pin 43 is positioned in the pin receiving opening 42 , with the pin 43 extending from the rod 36 through the slot 41 in the rigid tube 20 . The rod 36 can move so that the distal end 57 of the skirt 55 will project by at least 1 cm from an outer face of the planar end wall 34 of the cup member 30 . A coil spring 63 can be provided in the space between the proximal end 26 of the mounting block 24 and the base member 53 to bias the base member 53 to a position in which the exposed end 57 of the skirt 55 is withdrawn back over the sidewall 35 of the cup member 33 .
When using the embodiment of the invention shown in FIG. 6 , a plunger is magnetically attached to the magnet 30 and planar end wall 34 of the cup member 33 . The plunger is then positioned in its desired placement in a receiver of a well head as previously described herein. The plunger is then disengaged from the magnet 30 and planar end wall 34 of the cup member 33 by depressing the rigid tube 20 while simultaneously pulling the rod 36 in an opposite direction. The exposed end 57 of the skirt 55 holds the plunger in place while the movement of the rod 36 pulls the magnet 30 and cup member 33 away from the plunger so that the plunger is disengaged from its former magnetic attachment to the magnet 30 and cup member 33 .
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A device for removing and installing a plunger in a well head has a elongate rigid tube with a magnetic connector mechanism at it distal end for engaging the plunger during removal and installation of the plunger. A longitudinal opening or passage can be provided extending the entire longitudinal length of the rigid tube and magnetic connector mechanism. An elongate rod is positioned in the opening or passage so that the upper end of the rod can be moved downwardly to eject the lower end of the rod from the magnetic connector mechanism to thereby disconnect an attached plunger from the magnetic connector mechanism. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field Of The Invention
[0002] The present invention is directed to drilling fluid processing systems; shale shakers; to methods for using these things; and, in certain particular aspects, to the separation of lost circulation material from used drilling fluid.
[0003] 2. Description of Related Art
[0004] In the oil and gas industries, shale shakers use screens to treat drilling fluid contaminated with undesirable solids. Typically such apparatuses have a basket, deck, or other screen holding or mounting structure mounted in or over a receiving receptacle or tank and vibrating apparatus for vibrating one or more screens. Material to be treated is introduced to the screen(s) either by flowing it directly onto the screen(s) or by flowing it into a container, tank, or “possum belly” from which it then flows to the screen(s). Often, the screen or screens used to treat material is sealed in place on a screen deck, in a screen basket, or on screen mounting structure.
[0005] In the past it has been common to use multiple screens at multiple levels in a shale shaker to process drilling fluid, e.g., screens at one, two or three levels.
[0006] “Lost circulation” of drilling fluid occurs when, in drilling a wellbore, the circulation of drilling fluid to and then away from the drill bit ceases due to the porosity of the formation and/or due to fracturing of the formation through which the wellbore is being drilled. When lost circulation occurs, drilling fluid is pumped into the fractured formation rather than being returned to the surface. Often circulation is lost at some specific depth where the formation is “weak”, and that the fracture extends horizontally away from the borehole. Expressions used to describe rocks that are susceptible to lost returns include terms like vugular limestone, unconsolidated sand, “rotten” shale, and the like.
[0007] A wide variety of “lost circulation materials” (“LCM”) have been pumped into wellbores to fill or seal off a porous formation or to fill or seal off a wellbore fracture so that a proper route for drilling fluid circulation is re-established. Often lost circulation materials are generally be divided into fibers, flakes, granules, and mixtures.
[0008] Often it is also desirable to recover and retain the lost circulation material in the drilling mud system during continuous circulation. Screening the drilling mud for removal of undesired particulate-matter can also result in removal of the lost circulation material and, therefore, require continuous introduction of new lost circulation material to the drilling mud downstream of the mud screening operation.
[0009] The addition of lost circulation material compounds the separating problems because it, like the drilling fluid, is preferably cleaned and recirculated. Exiting the well is the drilling fluid of small size, the lost circulation material of a large size, and the undesirable material of a size therebetween, with the largest and smallest of the materials to be recirculated. One proposed solution to this separation problem is a conventional two step screening process as shown in U.S. Pat. No. 4,116,288. There the exiting mixture of drilling fluid, lost circulation material and undesirable material is first subjected to a coarse screening to separate the lost circulation material from the drilling fluid and undesirable material which drops to a second finer screen therebelow to separate the drilling fluid from the undesirable material. The drilling fluid and lost circulation material are then reunited for recirculation into the well. This system is susceptible to height restrictions and fine screen problems. The lost circulation material can be coated with undesirable material which will not go through a first screen, moves over and exits off of the top side of the first screen, and is circulated back into a well.
[0010] There are a variety of known drilling fluid processing systems, shale shakers, and methods for recovery of lost circulation material; including, for example, but not limited to, those in U.S. Pat. Nos. 6,868,972; 6,669,027; 6,662,952; 6,352,159; 6,510,947; 5,861,362; 5,392,925; 5,229,018; 4,696,353; 4,459,207; 4,495,065; 4,446,022; 4,306,974; 4,319,991; and 4,116,288 (all said patents incorporated fully herein for all purposes).
[0011] In certain prior systems, problems have been encountered with systems for screening out lost circulation material when undesirable material of the same size is also screened out.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention discloses, in certain aspects, methods and systems for processing drilling fluid to recover components thereof and, in one particular aspect for separating lost circulation material (or lost circulation material along with solids of similar size) from used drilling fluid. In certain aspects, the separated lost circulation material is recovered and used.
[0013] In certain particular aspects, such methods and systems employs a novel shale shaker according to the present invention with screening apparatus below an initial scalper screen apparatus for separating lost circulation material (and/or material of similar size) from used drilling fluid.
[0014] A vibratory separator or shale shaker, in one embodiment according to the present invention has a screen or screens at separate levels as described herein according to the present invention. In one particular aspect, two lowermost screens can receive flow from a higher screen in parallel or in series. The present invention, in certain embodiments, includes a vibratory separator or shale shaker with a base or frame; a “basket” or screen mounting apparatus on or in the base or frame; screens at three or four different, spaced-apart distinct levels according to the present invention; vibrating apparatus; and a collection tank or receptacle. Such a shale shaker can treat drilling fluid contaminated with solids, e.g. cuttings, debris, etc.; and drilling fluid with lost circulation material (and/or material of similar size) therein. Such a shale shaker, in certain aspects, provides a separate exit stream from a second screening level which is primarily lost circulation material (and/or material of similar size).
[0015] Accordingly, the present invention includes features and advantages which are believed to enable it to advance the processing of drilling fluid with lost circulation material (and/or material of similar size) therein. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings.
[0016] Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention.
[0017] What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain preferred embodiments of the invention, other objects and purposes will be readily apparent to one of skill in this art who has the benefit of this invention's teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide the embodiments and aspects listed above and:
[0018] New, useful, unique, efficient, nonobvious drilling fluid processing systems; shale shakers; and methods of the use of these systems and shakers; and
[0019] Such shale shakers with screens at four levels according to the present invention with the last two screens operating in series or in parallel; and
[0020] New, useful, unique, efficient, nonobvious drilling fluid processing systems and shale shakers; and methods of their use for separating and recovering lost circulation material (and/or material of similar size) from spent drilling fluid.
[0021] The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention's realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of certain preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent's object to claim this invention no matter how others may later attempt to disguise it by variations in form, changes, or additions of further improvements.
[0022] The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly from a cursory inspection or review the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention or of the claims in any way.
[0023] It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention.
[0024] Certain aspects, certain embodiments, and certain preferable features of the invention are set out herein. Any combination of aspects or features shown in any aspect or embodiment can be used except where such aspects or features are mutually exclusive.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0025] A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings which form a part of this specification. These drawings illustrate certain preferred embodiments and are not to be used to improperly limit the scope of the invention which may have other equally effective or legally equivalent embodiments.
[0026] FIG. 1 is a schematic view of a system according to the present invention.
[0027] FIG. 1A is a perspective view of a shale shaker according to the present invention.
[0028] FIG. 2A is a side view, partially in cross-section, of a shale shaker according to the present invention.
[0029] FIG. 2B is a cross-sectional view of the screens and related structure of the shale shaker of FIG. 2A .
[0030] FIG. 2C is a cross-sectional view of a shale shaker according to the present invention.
[0031] FIG. 3A is a side cutaway view of a shale shaker according to the present invention.
[0032] FIG. 3B is a side cutaway view of a shale shaker according to the present invention.
[0033] FIG. 4A is a perspective exploded view of a system according to the present invention.
[0034] FIG. 4B is a schematic side view of the system of FIG. 4A .
[0035] FIG. 5A is a perspective exploded view of a system according to the present invention.
[0036] FIG. 5B is a schematic side view of the system of FIG. 5A .
[0037] Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and features of embodiments of the invention are described below and some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of preferred embodiments and are not intended to limit the invention or the appended claims. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. 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.
[0038] As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiment, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference. So long as they are not mutually exclusive or contradictory any aspect or feature or combination of aspects or features of any embodiment disclosed herein may be used in any other embodiment disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0039] FIG. 1 illustrates a system S according to the present invention which includes a derrick 1 that extends vertically over a wellbore 2 . A tubular work string 3 extends into the wellbore 2 , and extends from the earth's surface to a desired depth within the wellbore. A flow line 4 a is connected to the tubular work string 3 . A flow line 4 b is connected to annular space 5 formed between the outer surface of tubular work string 3 and the inner surface of wellbore 2 .
[0040] Drilling fluid (or “mud”) for the system in a mud pit 6 is circulated through the overall mud system via a mud pump 7 . During typical drilling operations, fluid is pumped into the tubular work string 3 by the mud pump 7 through the flow line 4 a , circulated out a bottom end 3 a of the tubular work string 3 (e.g., but not limited to, out from a drill bit 9 ), up an annulus 5 of the wellbore 2 , and out of the annulus 5 via the flow line 4 b.
[0041] Spent (or used) fluid mud exiting the wellbore annulus 5 through the flow line 4 b includes drilling fluid, drill cuttings, lost circulation material (and/or material of similar size), and other debris encountered in the wellbore 2 . Accordingly, the spent drill cuttings mixture leaving the well is directed to a separation device, such as one or more shale shakers 8 according to the present invention. The combined mixture of drilling fluid, added material (e.g. solids and/or lost circulation material, etc.), debris, and drilled cuttings are directed to the shale shakers 8 . Liquid drilling fluid passes through screens 8 a , 8 b , 8 c , 8 d which are at four different levels of the shale shakers 8 and is directed into the mud pit 6 (or the two lowermost screens are at the same level each receiving a portion of flow from the screen 8 b ). Drill cuttings and other solids pass over the screens 8 a - 8 d of the shale shakers 8 and are discharged (arrows 8 e , 8 f , 8 h ). With the proper selection of screen mesh for the screen 8 b , lost circulation material (with some material of similar size, if present) is separated by and discharged from the top of the screen 8 b (see arrow 8 f ). The recovered lost circulation material (and/or material of similar size) flows and/or is pumped to a reservoir or to a further processing apparatus 8 k . Optionally, the shale shakers 8 are like any other shale shaker disclosed herein according to the present invention.
[0042] Referring now to FIG. 1A , a shale shaker H according to the present invention has screens A 1 , A 2 , A 3 , A 4 , each of which is, according to the present invention, at one of four different levels (with screen or screening cloth or mesh as desired). The screens are mounted on vibratable screen mounting apparatus or “basket” B. The screens A 1 , A 2 , A 3 , A 4 , according to the present invention, may be any suitable known screen or screens, with the screen A 2 (or the screens A 2 and A 3 ) used to separate lost circulation material (and/or material of similar size). The basket B is mounted on springs C (only two shown; two as shown are on the opposite side) which are supported from a frame D. The basket B is vibrated by a motor and interconnected vibrating apparatus E which is mounted on the basket B for vibrating the basket and the screens. Elevator apparatus F provides for raising and lowering of the basket end. Fluid passing through the screens A 1 , A 2 , A 3 , A 4 flows into a receptacle R beneath the bottom screen A 4 . In certain aspects screen A 1 has the coarsest mesh of all the screens and acts as a scalping screen and the screens A 3 and A 4 provide fine screening. The exit feeds from the top sides of the screens A 1 , A 3 , A 4 may go to disposal or may be directed as described below for any embodiment of the present invention. The lost circulation material recovered from the top of the screen A 2 (or, optionally, from the tops of the screens A 2 and A 3 ) may be flowed, processed and treated as described for any embodiment of the present invention. As shown, the screens A 3 , A 4 operate in series, i.e., the underflow from the screen A 3 flows down to the screen A 4 . Optionally, the screens A 3 , A 4 may be operated in parallel with each receiving a portion of screen A 2 's underflow.
[0043] FIGS. 2A and 2B show a system 10 according to the present invention which includes a shale shaker 12 with a base 14 and a screen-supporting basket 16 . A vibrator apparatus 18 vibrates the basket 16 and screens mounted in it.
[0044] Four spaced-apart screens 21 - 24 are mounted in the basket 16 at different levels (e.g. spaced-apart six to eight inches) or put another way, at four different heights in the basket. In one particular embodiment the screen 21 is a scalping screen which, in one particular aspect removes relatively large pieces of material, e.g. with mesh sized so that pieces ⅛″ and 1/64″ is used. In one aspect, the screen 21 has a mesh size such that pieces greater than 1/16″ are removed (and pieces of, among other things, solids and/or lost circulation material that are 1/16″ or smaller in largest dimension pass through the screen 21 (e.g., but not limited to graphite ball lost circulation material that are 1/16″ in largest dimension or slightly smaller).
[0045] The screen 22 has a mesh size as chosen for removing material of a certain largest dimension or larger, including, but not limited to solids, debris, drilled cuttings, desirable additives, and/or lost circulation material. In one aspect the mesh size is chosen in cooperation with the mesh size of the screen 21 so that the screen 22 removes lost circulation material (and solids or pieces of similar size) and, in one particular aspect the mesh size is chosen so that lost circulation material of a largest dimension of 1/16″ or greater does not pass through the screen 22 and flows from the top thereof In one aspect such lost circulation material is graphite balls.
[0046] The screens 23 and 24 further filter out solids from the flow through the screen 22 and, in certain aspects, the screens 23 and 24 act as typical standard fine screening screens used to process a mixture of drilling fluid and solids.
[0047] The exit streams from screens 21 , 23 , and 24 exit from the tops of their respective screens and flow down to a container, system or apparatus 20 for storage and/or further processing. Drilling fluid flowing through the screens flows down to a sump or container 26 and from there to a reservoir or in one aspect, back to an active rig mud system. The exit stream from the screen 22 , in particular aspects, has wet lost circulation material (or wet lost circulation material along with solids of similar size) of at least 50% by volume; and in one particular aspect at least 75% lost circulation material by volume (in one example, the output is 50% lost circulation material and 50% solids of similar size). In certain aspects, screen mesh size is chosen so that a relatively large percentage of the flow off the top of the screen is lost circulation material, e.g. by volume, up to 50%, 75%, or up to 90%.
[0048] Fluid with some solids therein (including the lost circulation material of a certain size, if present) that flows through the screen 21 is directed to the screen 22 by a flowback barrier (or plate) 31 . Optionally, the flowback barrier 31 is eliminated. The material (including lost circulation material of a certain size, if present) that exits from the top of the screen 22 is transferred to a reclamation system 40 (which, in one aspect, is, has or includes an auger apparatus 42 for moving solids to and/or from the reclamation apparatus).
[0049] Fluid with solids that flows through the screen 22 is directed to the screens 23 and 24 by a flowback barrier or plate 32 , a flow channel 32 a , and a weir 32 b . Fluid with solids that flows through the screen 23 is directed to the sump 26 through a channel 51 by a flowback barrier 33 and a channel 33 a . When the level of fluid (with material therein) exceeds the height of the weir 32 b , part of the flow from the screen 22 flows into the flow channel 50 bypassing the screen 23 and flowing to the screen 24 (thus, the screens 23 , 24 in this manner operate in parallel). Fluid flowing through the screen 24 flows into the sump 26 . Optionally, the screen 21 includes an end weir 21 w and fluid and material on top of the screen 21 in a pool 21 p that exceeds the height of the weir 21 w bypasses the screen 21 and flows to the screen 22 via a channel 17 . The flowback barriers extend under substantially all of the surface of the particular screens under which they are located. Any one, two, or three of the flowback barriers can, optionally, be eliminated.
[0050] The screens 21 - 24 are at typical screen tilt angles, e.g. between 6 degrees to 12 degrees from the horizontal and in one aspect, about 8 degrees.
[0051] A shale shaker 10 a shown in FIG. 2C is like the system 10 , FIG. 2A (and like numerals indicate like parts). Two screens, the screens 22 and 23 , are used in the shale shaker 10 a to remove LCM material (and/or material of similar size) . The two screens 22 , 23 act in parallel with flow from the upper screen 21 flowing both to the screen 22 and, over a weir 22 w , to the screen 23 . Fluid flowing through the screen 22 flows to a channel 50 a and then down to the screen 24 as does fluid flowing through the screen 23 .
[0052] FIGS. 3A and 3B show a shaker system 10 b like the system 10 , FIG. 2A (like numerals indicate like parts). The shaker 10 b has a collection chute 60 which receives material from top of a screen 21 a (like the screen 21 , FIG. 2A ) and from which the material flows down to a cuttings ditch, pit, or collector 19 . An auger system 70 receives material from the top of a screen 22 a (like the screen 22 ) and augers the material into a conduit 70 a from which it flows to storage or further processing apparatus 70 b . The flows from the tops of screens 23 a (like screen 23 ) and 24 a (like screen 24 ) flow to the cuttings ditch (etc.) 19 . Fluid flowing through the screens flows to a sump 26 a (like the sump 26 ). In one aspect, the screen 22 a is used to recover LCM (and/or material of similar size), optionally, as in FIG. 2C , both screens 22 a and 23 a are used to recover LCM (and/or material of similar size).
[0053] Material recovered from the top of a second screen in systems according to the present invention (e.g. from the top of the screen 8 b , 21 or 21 a ) can, according to the present invention, be sent to additional treatment apparatus for further processing; including, but not limited to, a sprinkle-wash system for solids recovery, centrifuge(s), hydrocyclone(s), and/or magnetic separation apparatus. This material from the tops of these screens is, in one aspect, lost circulation material. In one aspect, considering the totality (100%) of the lost circulation material in a drilling fluid mixture fed to a top scalping screen of a system according to the present invention, about 97% of this lost circulation material flows to the second screen and about 95% (95% of the original totality of the material) is recovered from the top of the second screen; or optionally, a combination of similar sized material, including both LCM and other material is recovered.
[0054] FIGS. 4A and 4B illustrate a quad-tier system 100 according to the present invention which has screen decks 101 , 102 , 103 , and 104 . A feed 105 of a drilling fluid mixture is fed onto a first deck 101 with a plurality of screens 101 a , 101 b , 101 c (may be any suitable number of screens). Drilling fluid (with some solids) flowing through the screens 101 a - 101 c flows to a chute 106 and from there down to the deck 102 . Overflow 107 from the deck 101 flows over a weir 108 (of a pre-determined height) down to the deck 102 . Oversized material 109 flows off the top of the screen 101 c.
[0055] Drilling fluid with some solids flowing through screens 102 a (four shown; may be any suitable number of screens) flows to chutes 116 and from there to the deck 103 . Oversize material 119 flows off the tops of screens 102 a . A weir 118 prevents any overflow from the top of the screens 102 a from flowing down to the deck 103 .
[0056] Drilling fluid with some solids flowing through screens 103 a (size shown; may be any number) of the deck 103 flows to a diverter 126 and from there to a collection structure, e.g. a tank, sump or receptacle. Overflow from the top of the screens 103 a flows to a channel apparatus 128 and from there to a channel apparatus 138 which directs this flow to the top of the deck 104 . Oversized material 129 flows off the tops of end screens 103 a.
[0057] Drilling fluid flowing through screens 104 a (four shown; any number may be used) flows down to chutes 136 and then to the tank, sump, or receptacle. Oversized material 139 flows off tops of end screens 104 a.
[0058] The oversized material flows, 109 , 119 , 129 and 139 flow to typical collection sump, pit tank, or receptacle or storage apparatus and/or to subsequent processing apparatus.
[0059] In one particular aspect of the system 100 , the deck 101 is a coarse screening deck (e.g. but not limited to the screen 8 a , screen A 1 , screen 21 or screen 21 a ); the deck 102 is a medium mesh screening deck (e.g. but not limited to, like the screen 8 b , screen A 2 , screen 22 , or screen 22 a ); the deck 103 is a medium or fine screening deck (e.g., but not limited to, like the screen 8 c , screen A 3 , screen 23 or screen 23 a ); and the deck 104 is a fine screening deck (e.g., but not limited to, like the screen 8 d , screen A 4 , screen 24 or screen 24 a ).
[0060] FIGS. 5A and 5B illustrate a system 200 according to the present invention which is, in some ways, like the system 100 , FIG. 4A . In the system of FIG. 4A underflow from the deck 102 flows to both the deck 103 and the deck 104 . In the system 200 flow from the deck 101 flows to both the deck 102 and the deck 103 , with underflow from both of these decks flowing to the deck 104 .
[0061] Drilling fluid with some solids (underflow from the deck 101 ) flows from the deck 101 down to the deck 102 . Overflow from the deck 102 flows via the channel apparatus 128 a and channel apparatus 204 to the deck 103 . Underflow from the deck 102 flows to the chutes 116 and is diverted to the deck 104 by a diverter 202 (with handles 203 ) and via a channel apparatus 206 and a channel apparatus 208 to the deck 104 . In one aspect the diverter 202 is connected to the channel apparatus 204 (indicated by the wavy lines on both).
[0062] Underflow having passed through the deck 103 and chutes 116 a (like the chutes 116 ) is diverted by a diverter 202 a (like the diverter 202 ) to the deck 104 . Underflow having passed through the deck 104 flows to the chutes 136 and then to collection, storage, tank, or receptacle.
[0063] The various chutes, diverters, and channel apparatuses in the systems 100 and 200 are interchangeable, in one aspect, so that series or parallel flow to and from one or more selected decks is facilitated. In certain aspects, the chutes, diverters and channel apparatuses are made of metal, plastic, or composite material.
[0064] In the system 100 , FIG. 4A , the channel apparatus 128 has three flow passages 128 a , 128 b , 128 c . The diverter 126 has two flow passages 126 a , 126 b . The channel apparatus 138 has flow passages 138 a , 138 b , 138 c . In the system 200 , FIG. 5A , the channel apparatus 128 a has flow channels 128 c , 128 d . The channel apparatus 204 has flow passage 204 a , 204 b . The channel apparatus 206 has flow passages 206 a , 206 b . The channel apparatus 208 has flow passages 208 a , 208 b.
[0065] The present invention, therefore, provides in at least certain embodiments, a system for processing a mixture of drilling fluid and solid material to separate at least one component of the mixture by size from the mixture, the system including a vibratable basket; a sump at a bottom of the basket; a plurality of spaced-apart screens including a first screen deck, a second screen deck positioned below the first screen, a third screen deck positioned below the second screen deck, and a fourth screen deck positioned below the third screen; the screens mounted in the vibratable basket and vibratable therewith; the first screen deck having screen mesh of a first size to remove from a top of the first screen deck solids from the mixture with a largest dimension equal to and larger than a first dimension so that material with a largest dimension smaller than the first dimension is passable down through the first screen deck; the second screen deck having screen mesh of a second size to remove from a top of the second screen solids from the mixture passing to the second screen deck from the first screen deck which have a largest dimension equal to or larger than the second size so that material with a largest dimension smaller than the second size is passable down through the second screen deck, material and fluid passing through the second screen deck comprising a secondary flow; diversion apparatus connected to the basket positioned for providing at least a portion of the secondary flow to the third screen deck and, selectively, a portion of the secondary flow to the fourth screen deck; the third screen deck having screen mesh of a third size, and the fourth screen deck having screen mesh of a fourth size for removing solids from the secondary flow on the top of the third screen deck and from the top of the fourth screen deck; and drilling fluid flowing through the first screen deck, the second screen deck and one of the third screen deck and fourth screen deck flowing down into the sump. Such a system may have one or some, in any possible combination, of the features and aspects described above for any system according to the present invention.
[0066] The present invention, therefore, provides in at least certain embodiments, a system for processing a mixture of drilling fluid and solid material to separate at least one component of the mixture by size from the mixture, the system including: a vibratable basket; a sump at a bottom of the basket; a plurality of spaced-apart screens including a first screen deck, a second screen deck positioned below the first screen, a third screen deck positioned below the second screen deck, and a fourth screen deck positioned below the third screen; the screens mounted in the vibratable basket and vibratable therewith; the first screen deck having screen mesh of a first size to remove from a top of the first screen solids from the mixture with a largest dimension equal to and larger than a first dimension so that material with a largest dimension smaller than the first dimension is passable down through the first screen deck; the second screen deck having screen mesh of a second size to remove from a top of the second screen solids from the mixture passing to the second screen deck from the first screen deck which have a largest dimension equal to or larger than the second size so that material with a largest dimension smaller than the second size is passable down through the second screen deck, material and fluid passing through the second screen deck comprising a secondary flow; diversion apparatus connected to the basket positioned for providing at least a portion of the secondary flow to the third screen deck and, selectively, a portion of the secondary flow to the fourth screen deck; the third screen deck having screen mesh of a third size, and the fourth screen deck having screen mesh of a fourth size for removing solids from the secondary flow on the top of the third screen deck and from the top of the fourth screen deck; drilling fluid flowing through the first screen deck, the second screen deck and one of the third screen deck and fourth screen-deck flowing-down into the sump; wherein the first screen deck is a scalping deck; wherein the screen mesh of a second size is suitable for removing solids the size of lost circulation material, said solids including pieces of lost circulation material and pieces of material other than lost circulation material; the drilling fluid mixture introduced to the system to be treated by the system includes a first amount of lost circulation material; the second deck is able to remove a second amount of lost circulation material; the second amount at least 75% of the first amount; and reclamation apparatus for receiving the lost circulation material.
[0067] The present invention, therefore, provides in at least certain embodiments, a method for treating a mixture of drilling fluid and solid material to separate at least one component of the mixture by size from the mixture, the method including: feeding the mixture to a vibratable basket of a system, the system as any described herein according to the present invention, and the method further including flowing drilling fluid through a first screen deck, a second screen deck and one of a third screen deck and a fourth screen deck of the system down into a sump; or flowing drilling fluid through a first screen deck, and one of a second screen deck and a third screen deck flowing down into a sump.
[0068] In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. §102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35 U.S.C. §103 and satisfies the conditions for patentability in §103. This specification and the claims that follow are in accordance with all of the requirements of 35 U.S.C. §112. The inventors may rely on the Doctrine of Equivalents to determine and assess the scope of their invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. | Methods and systems are disclosed employing a quad-tier shale shaker for processing a mixture of drilling fluid and solids which solids include, in one aspect, lost circulation material (and/or material of size similar to the size of the lost circulation material). This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b). | 1 |
RELATED APPLICATIONS
This application is a National Phase Application of PCT Patent Application Ser. No. PCT/IL2004/001012 having International Filing Date of Nov. 4, 2004, which claims the benefit of U.S. Provisional Patent Application No. 60/517,095 filed on Nov. 5, 2003. The contents of the above Applications are all incorporated herein by reference.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to methods and apparatus for improving visual perceptions in accordance with the techniques described in the above-cited related applications. The following background will be helpful in understanding the improvements of the present invention.
SCIENTIFIC BACKGROUND
The visual system is a highly sophisticated optical processing mechanism, classically described as a hierarchy of visual processing stages (though recent views emphasize backward projections), starting from light detection and transduction in the eye (i.e. photoreceptors) through several stages of spatial integration, each stage forming receptive fields of increasing complexity.
Not all components imaged on the retina are equally perceived; some are constrained by the efficiency of neural processing in the brain. An important stage in image analysis in the primary visual cortex involves receptive fields (units) sensitive to image contrast that varies in a specific direction (orientation selectivity) on a specific scale (size selectivity). Human contrast sensitivity is best described by the aggregate response of these units (filters).
Cortical cells (neurons) are highly specialized and optimized as image analyzers, so they respond only to a limited range of parameters (filters) of the visual image, such as orientation, location in the visual field, and spatial frequency. Thus, to characterize an image, visual processing involves the cooperative activity of many neurons. These neural interactions contribute both excitation and inhibition. Spatial interactions between oriented receptive fields are an important factor in modulating activity of the corresponding neuronal units.
Contrast is one of the most important parameters activating cortical cells involved in vision processing. Responses of individual neurons to repeated presentations of the same stimulus are highly variable (noisy). Noise may impose a fundamental limit on the reliable detection and discrimination of visual signals by individual cortical neurons. Neural interactions determine the sensitivity for contrast at each spatial frequency, and the combination of neural activities set the Contrast Sensitivity Function (CSF). Theory suggests that the relationship between neuronal responses and perception are mainly determined by the signal-to-noise ratio (S/N ratio) of the neuronal activity. The brain pools responses across many neurons to average out noisy activity of single cells; thus improving the signal-to-noise ratio, leading to substantially improved visual performance.
In several studies, it has been shown that the noise of individual cortical neurons can be brought under experimental control by appropriate choice of stimulus conditions: Kasamatsu, T., Polat, U., Pettet, M. W. & Norcia, A. M. Colinear Facilitation Promotes Reliability of Single-cell Responses in Cat Striate Cortex. Exp Brain Res 138, 163-72. (2001); and Polat, U., Mizobe, K., Pettet, M. W., Kasamatsu, T. & Norcia, A. M. Collinear Stimuli Regulate Visual Responses Depending on Cell's Contrast Threshold. Nature 391, 580-4 (1998). Such studies also show that contrast sensitivity at low levels can be increased by a factor of 2 through control of stimulus parameters. At the neural level, the improvement in sensitivity would not be expected or largely reduced without a concurrent decrease in response noise. This precise control of stimulus conditions leading to increased neuronal efficiency is fundamental in initiating the neural modifications that are the basis for brain plasticity.
Brain plasticity relates to the ability of the nervous system to adapt to changed conditions, sometimes after injury or strokes, but more commonly in acquiring new skills. Brain plasticity has been demonstrated in many basic tasks, with evidence pointing to physical modifications in the adult cortex during repetitive performance. Several studies demonstrate the plasticity of neural interactions resulting from repetitive performance of specific visual tasks leading to improved visual performance. The improved visual functions, like skill learning, were retained after a few years of retesting. Both an increased range of excitatory interactions and reduced inhibition were observed in subjects with normal vision, and in monkeys. These studies point to activity-dependent plasticity of the visual cortex, where the specific connections activated throughout repetitive performance are modified, leading to improved performance.
The technology in the above-cited related applications probes specific neuronal interactions, using a set of patient-specific stimuli that improve neuronal efficiency and induce improvement of CSF due to a reduction of noise and increase in signal strength—followed by a marked improvement in spatial resolution (Visual Acuity).
“Lateral Masking”: Modulation of CSF
The typical building block of the the visual stimulations is the Gabor patch ( FIGS. 1 a and 1 b ). “Gabor Patches” are widely used in the field of visual neuroscience. They have been shown to efficiently describe and match the shape of receptive fields of neurons in the primary visual cortex and thus represent the most effective stimulation.
The set of Gabor functions is defined as a collection of odd (sine) and even (cosine) wave functions with limited spatial extent (and/or temporal extent).
Go ( x,y )= Aoexp (−(( x−xo )2+( y−yo )2)/σ2)*sin(2π/λ*( x ·cos(θ)+ y·sin(θ)))
Contrast response of a single neuron can be modulated by activity of neighboring neurons, as shown by single-unit recordings of neuronal activity in the visual cortex of cats and monkeys.
Recent research by Polat, U., Mizobe, K., Pettet, M. W., Kasamatsu, T. & Norcia, A. M., conducted invasively, utilizing cat subjects, demonstrated the linear relationship between contrast and neuronal response (green line) as shown in FIG. 2 . Research published in Nature in 1998 revealed a non-linear response to the same target when surrounded by flanking images (blue line). These flanking images where found to increase response (facilitation) at lower contrast levels and decrease response (suppression) at higher contrast levels. This fundamental discovery regarding the neural connections responsible for vision in cats is also fundamental to the techniques involved in the present invention for vision improvement in humans.
It has been demonstrated that contrast sensitivity of adult human subjects at low levels can be significantly increased through specific control of the Gabor patches parameters. This stimulation-control technique, where collinearly-oriented flanking Gabors are displayed in addition to the target gabor image, is called “Lateral Masking”.
The results shown in FIGS. 3 and 4 are derived from subjects (adults) with normal vision, who were exposed to psychophysical tasks using the lateral masking technique:
When subjects practice contrast modulation under a very precise and subject-specific stimuli regimen, a dramatic improvement in contrast sensitivity is achieved.
About Amblyopia
Amblyopia is defined as reduced visual acuity in an eye that cannot be cured or improved by refractive correction, while eye pathology does not exist. It is a developmental abnormality of the central nervous system that leads to impaired vision. It is caused during early childhood, when one of the eyes is crossed and/or significantly unfocused. When the difference between the two images sent from the eyes to the brain is such that the brain cannot fuse both the images to a single one, the “weak” eye's image is drastically suppressed by the brain to avoid double or blurry vision. Amblyopia is a common public health problem that affects 2%-4% of the population in the industrial world.
The visual function of the amblyopic eye is dramatically reduced. Amblyopic visual acuity is defined as less than 20/30, but can be as bad as the “legally blind” level (20/200) and sometimes even worse. According to the NIH/NEI Visual Acuity Impairment Study (VAIS), amblyopia is the leading cause of monocular vision loss in the 20 to 70+ age group, surpassing diabetic retinopathy, glaucoma, macular degeneration and cataract.
Patients with amblyopia substantially use only one eye, and do not have three-dimensional (stereoscopic) vision. Naturally, their spatial orientation is impaired and they have reduced peripheral vision. They are at increased risk of blindness if vision for any reason is lost in their good eye. Amblyopia may also lead to restrictions in educational and occupational opportunities, and may also affect a person's lifestyle. A Quality of Life study conducted among adult amblyopes demonstrates the extent of these influences.
Ideally, amblyopia is diagnosed by a pediatrician when a child is quite young. Treatment by a pediatric ophthalmologist has the potential to correct the condition by the time the child is three or four years of age. However, to treat this condition, a young child must wear an eye patch that covers the good eye for an extended period of time. A significant number of children find patches uncomfortable or socially embarrassing, and have a natural aversion to having their only good eye covered. The result is poor compliance, which leads to ineffective treatment. Lack of compliance, combined with late detection and unsuccessful treatment, result in a significant number of children reaching adulthood (the critical age of nine and above) suffering from the condition.
Amblyopia is considered treatable only in children younger than nine years of age, primarily by occluding the good eye and forcing the “lazy eye” to function. It is considered untreatable in individuals older than nine years, an age that is referred to as the “critical age”.
About Myopia
Myopia is defined as a refractive condition in which rays of light entering the eye parallel to the optic axis are brought to a focus in front of the retina. It can be also referred as a refractive condition where the farthest point of focus is located at a point near to the observer, and not at infinity, thus Myopia is often referred as Near-sightedness or Shortsightedness. When one is nearsighted, distance vision is blurred at all times while near vision is often excellent within a certain range.
There are a number of causes of this optical condition. The eyeball may be too long, causing the image to be focused short of the retina at the back of the eye. Or, the focusing lenses of the eye are too strong.
Eyeglasses and contact lenses are the safest and most practical optical remedies. The lens power, whether it be in spectacles or contact lenses, is a minus power, which cancels the excessive plus power of near-sightedness. The image now comes to a clear focus at the back of the eye, on the retina.
Myopia often occurs combined with Astigmatism. Astigmatism is distorted vision caused by a warpage in the optics of the eye. As shown in FIG. 11 a , the image presented to the retina at the back of the eye is out of focus only for light waves entering at a certain angle, along a certain meridian. As shown in FIG. 11 b , astigmatism is generally corrected by a lens (spectacle or contact lens) which is astigmatic opposite to that of the eye. Such a lens is called a toric or cylinder lens.
OBJECTS AND BRIEF SUMMARY OF THE PRESENT INVENTION
An object of the present invention is to provide a method and apparatus for improving visual perception with respect to various types of eye conditions generally, but particularly with respect to amblyopia, presbyopia and myopia, with or without astigmatism.
According to one aspect of the present invention, there is provided a method of improving the visual perception ability of a person with respect to a particular eye condition of at least one eye, comprising: in at least one evaluation session of an evaluation phase, displaying to the person a plurality of images selected to test the visual perception ability of the person with respect to at least one visual defect, and to elicit responses from the person indicative of the level of the person's visual perception ability with respect to the at least one visual defect; utilizing the responses to select another plurality of images designed to treat the person with respect to a detected visual defect and thereby to improve the visual perception ability of the person with respect to the detected visual defect; and in a treatment phase, applying to the at least one eye of the person, training glasses with reduced refraction for the respective eye; and displaying to the person the another plurality of images in at least one treatment session while the training glasses are applied to the at least one eve of the person. until the visual perception ability of the person has been improved with respect to the detected visual defect.
According to another aspect of the present invention, there is provided apparatus for improving the visual perception ability of a person with respect to a particular eye condition of at least one eye, comprising: a display device for displaying images to the person: an input device for displaying images to the person; training glasses to be worn by the person and having a reduced refraction with respect to at least one eye of the person; and a processor programmed such that: in an evaluation phase, before the training glasses have been applied to the person, the processor controls the display device to display to the person a plurality of images selected to test the visual perception ability of the person with respect to at least one visual defect, and utilizes responses inputted by the person via the input device to select another plurality of images designed to improve the visual perception ability of the person with respect to a detected visual defect: and in treatment phase, after the training glasses have been applied to the person, the processor controls the display device to display to the person the another plurality of images to thereby improve the visual perception ability of the person with respect to the detected visual defect.
According to the preferred embodiments of the invention described below, the treatment phase includes a plurality of treatment sessions in each of which are displayed to the person a plurality of images designed to elicit responses to be used for selecting the plurality of images in a subsequent treatment session such as to progressively improve the visual perception ability of the person with respect to the detected visual defect. After at least one treatment session, the refraction of the training glasses is increased, decreased, or remains the same for the next treatment session as determined in order to progressively improve the visual perception ability of the person with respect to the detected visual defect. At least one predetermined parameter of the plurality of images displayed in one treatment session is varied in the subsequent treatment session.
More particularly, in the described preferred embodiment, the treatment phase includes a plurality of treatment sessions each of which includes a plurality of visual perception tasks. In each such task there is displayed to the person at least one image including stimuli designed to elicit a response useful for selecting at least one other image to be displayed in the subsequent visual perception task of the respective treatment session such as to progressively improve the visual perception ability of the person with respect to the detected defect.
In one described preferred embodiment, the visual perception tasks in at least some of the sessions in the treatment phase include spatial frequency changes in which the spatial frequency of the stimuli is changed. As described, the spatial frequency is changed starting with lower spatial frequencies and progressively moving to higher spatial frequencies.
In another described preferred embodiment, in at least some of the sessions in the treatment phase, the orientation of the stimuli is changed. The described preferred embodiment is one wherein the eye condition includes astigmatism characterized by a distortion area in an astigmatic zone; and wherein, in at least some of the treatment sessions in the treatment phase, the orientations of the stimuli are changed by progressing towards the distortion area in the astigmatic zone.
In all the described preferred embodiments, the treatment phase includes a sufficient number of treatment sessions to improve the person's sensitivity contrast function by the person achieving a desired range of contrast levels.
The invention is described below in a system wherein the plurality of images are displayed in a client's terminal in both the evaluation phase and the treatment phase; and wherein the elicited responses are communicated to a remotely-located server and utilized to select the another plurality of images designed to treat the person with respect to the detected visual defect.
BRIEF DESCRIPTION OF THE DRAWINGS
The file of this patent contains at least one drawing executed in color photograph. Copies of this patent with color photograph(s) will be provided by the Patent and Trademark Office upon request and payment of necessary fee.
The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIGS. 1 a - 4 are diagrams referred to in the above description of the background;
FIG. 5 is a series of diagrams illustrating various manipulations of visual stimuli that may be involved in a treatment according to the present invention;
FIG. 6 is a diagram illustrating the reduced CSF (Contrast Sensitivity Function) in amblyopic patients;
FIG. 7 is a diagram illustrating abnormal lateral interactions is amblyopic patients;
FIG. 8 is a diagram illustrating visual acuity improvement in patients treating according to the present invention;
FIG. 9 is a diagram illustrating visual acuity improvement during the treatment phase and improvement subsequently, FIG. 10 is a diagram illustrating contrast sensitivity function improvement during the treatment phase and improvement subsequently;
FIGS. 11 a and 11 b are diagrams illustrating myopic and astigmatic eye conditions, respectively;
FIG. 12 is a diagram illustrating reduced CSF in myopic patients;
FIG. 13 is a diagram illustrating enhancing lateral interactions in myopic patients treated in accordance with the present invention;
FIG. 14 illustrates improvements in uncorrected visual acuity of patients treated in accordance with the present invention;
FIG. 15 is a diagram illustrating improvements in CSF during the treatment phase in accordance with the present invention;
FIG. 16 is a block diagram illustrating the architecture of one system constructed in accordance with the present invention;
FIG. 17 is a flow chart illustrating the operations performed by the server side in a treatment session cycle;
FIG. 18 is a flow chart illustrating the operations performed by the server side in a selected VPT (visual perception task) session;
FIG. 19 is a flow chart illustrating the analysis of an evaluation sessions; and
FIGS. 20 and 21 are flow charts illustrating the analysis of treatment sessions.
DESCRIPTION OF PREFERRED EMBODIMENTS
Treatment Concept—Overview
As will be described more particularly below, the present invention involves a computerized interactive treatment in which the patient is exposed to a series of psychophysical visual tasks—“Visual Perception Tasks (VPT)”. A VPT aims to measure or improve a person's visual perception process. In fact, each VPT is generally designed to target a specific aspect of the visual perception process.
The various VPT's implemented by the system have structuring for performing all the following operations:
. Providing a patient with visual stimuli designed to stimulate one or more areas of the patient's visual cortex; . Receiving responses to the visual stimuli from the patient using an input device (e.g., the computer mouse); and then . Providing more visual stimuli based on responses to the previous visual stimuli, until a threshold level is reached.
The treatment is administered in successive 30-minute sessions, each session comprised of a series of VPT's., 2-3 times a week for a total of approximately 30 sessions.
As each patient suffers from individual specific neural capabilities, the treatment is personalized—specifically tailored to each individual subject. Subject specificity is achieved by the following measures:
1. Analysis and identification of each subject's neural deficiencies or inefficiencies or within normative range capabilities through performance of a set of visual perception tasks to which the subject is exposed. This stage is called the computerized evaluation stage, and is usually comprised of up to three sessions. As a result, a treatment plan is defined.
2. Based on said analysis, administering patient-specific stimuli in a controlled environment. The visual stimuli parameters are algorithmically controlled and tailored to each subject's needs in order to address and improve the identified neural deficiencies or inefficiencies or enhance the neuronal activity beyond the normative range. This is the treatment stage and is usually comprised of approximately 30 to 50 treatment sessions, depending on each individual performance.
Each treatment session is designed to train, directly and selectively, those functions in the visual cortex that were diagnosed to be potentially enhanced. During each session an algorithm analyzes the patient's responses and accordingly adjusts the level of visual difficulty to the range most effective for further improvement.
Between sessions, the performance and progress of the patient are measured and taken into account by the algorithm for the definition of the visual stimuli parameters of the next therapeutic session. Thus, for each subject an individual training schedule is designed based on the initial state of visual performance, severity of dysfunction and progress in therapeutic training.
The visual stimuli parameters are algorithmically controlled and tailored to each subject's needs. Among these parameters are: Spatial Frequencies, Spatial arrangement of the Gabor patches, Contrast level, Orientation (local and global), Tasks Order, Context and Exposure Timing.
The foregoing treatment may be used to improve vision of subjects with several eye conditions, including but not limited to: (1) Amblyopia, (2) Myopia, (with or without Astigmatism) (3) Presbyopia, (4) Hyperopia, (5) Emmetropia, (for obtaining super-normal vision) (6) Ammetropic post refractive surgery patients, (being left with residual refractive errors), and (8) Eye diseases causing reduced vision, such as glaucoma or age-related macular degeneration (AMD). It may also be used to reduce progression of myopia in childhood.
The invention is particularly useful for treating amblyopia and myopia (with or without astigmatism), and is therefore described below with respect to such treatments.
Amblyopia Treatment Principles
Amblyopia, as mentioned above, is defined as reduced visual acuity in an eye that cannot be cured or improved by refractive correction. Even when using the best refractive correction, Amblyopes are characterized by several functional abnormalities in spatial vision, including: reduced Visual Acuity, reduced Contrast Sensitivity Function (CSF), and impaired contour detection. The reduction in CSF, which is mainly pronounced at high spatial frequencies, is believed to result from a low S/N (signal-to-noise) ratio. A low S/N ratio is shown to limit performance on letter identification.
The reasons Amblyopes suffer from these functional abnormalities that can not be remedied through the use of corrective lenses or surgery are defects in the neurological component of a person's visual perception process. Amblyopes suffer from abnormal neural interactions and reduced excitation and increased inhibition, an effect that underlies deficient contrast response, and crowding effect.
FIG. 7 presents the abnormal “Lateral Masking” graph resulting from those abnormal neural interactions compared to a normative “Lateral Masking” graph.
The Amblyopia treatment aims to improve the deficient lateral interactions, increase the S/N ratio, and improve the impaired contour integration and spatial localization.
This is mainly achieved through Visual Perception Tasks (VPTs) focusing in reduction of the lateral inhibition. Practicing the lateral interactions leads to an increased range of those interactions.
Through the personalized treatment sessions, the size (spatial-frequency) and orientation of the stimuli are changed, starting with lower spatial-frequencies and progressively moving to the higher ones, with four orientations at each size.
The trained spatial frequencies are selected according to the level of abnormality, which is measured during the computerized evaluation. Amblyopes often suffer from subnormal contrast sensitivity in mid to high special frequencies.
For optimal improvement, the achieved contrast thresholds should enter into a contrast funnel. If contrast exceeds this funnel, the Gabor patches are elongated towards the local orientation axis, in order to decrease contrast thresholds.
Meridional Amblyopia, which means unequal contrast response at various orientations despite optimal refractive correction, is addressed by changing the orientation, starting with the easier one (at which lower contrasts are achieved) and progressively moving to the harder one.
The zone of suppression receives high attention, as abnormal lateral interactions are expressed in increased suppression. The VPTs initially concentrate at the area of low suppression level. Upon improvement, and creation of a certain level of facilitation, the focus will gradually shift to the area of higher suppression level, which will follow to improve as well.
The Amblyopia treatment also aims to improve the spatial localization. This is achieved through practicing of alignment displacement VPTs. The treatment is uniocular; the amblyopic eye is trained, while the fellow eye is occluded with a semi-translucent lens.
The treatment is performed using the best refractive correction for the Amblyopic eye. The best refractive correction should be also used in all daily activities. If major refraction difference exists between the eyes, contact lenses only should be used, to avoid projection of different image sizes from the eyes to the brain.
The above described NVC (neural vision correction) treatment principles have been proven in the clinical treatment of amblyopia, a condition where the visual system is underdeveloped due to abnormal visual input to the brain during the critical period (up to age nine). The treatment has been tested in controlled randomized placebo clinical trials on adults (aged nine to 55) having baseline vision between 20/30 and 20/100 in their amblyopic eye. The trials were performed under the auspice of the Sheba Medical Center in Israel. Certified external auditors routinely monitored the trials for GCP compliance.
The Clinical Trial Success Criteria Were as Follows:
1. Best Corrected Visual Acuity (BCVA) improvement of a minimum of two lines in ETDRS chart of over baseline, in a minimum of 60% of completed subjects.
2. Maintenance of the improved visual acuity (+/−50%) after three months post-treatment.
The Following are the Clinical Study Results Highlights:
1. The success rate within the treatment group (44 patients) was 70.5% (31 out of 44 patients).
2. The average improvement among all 44 patients (including patients that did not show improvement) was 2.5 ETDRS lines.
3. The control group showed no improvement.
4. Average improvement within the sub-group that was successfully treated (70% of the patients) was 3.1 lines, which is a doubling of the visual acuity.
5. Almost half of the successfully treated sub-group reached 20/25 vision or better, while 19% (6 patients) improved to 20/20 vision or better (“super-normal vision”).
6. Among patients having a baseline VA of 20/50 and worse, 70% achieved a final VA of 20/40 and better.
7. The contrast sensitivity function (CSF) of the treatment group improved remarkably and significantly. The CSF average—after treatment was within the normal range.
8. Additional visual functions, i.e. binocular functions and reading abilities (near visual acuity), were significantly improved among the treatment group.
9. Retention monitoring at 12 months post treatment showed excellent results.
FIG. 8 presents the individual Visual Acuity improvement of all treatment group patients. FIG. 9 presents the treatment group average Visual Acuity improvement during the treatment phase and the retention of this improvement one year post treatment. FIG. 10 presents the treatment group average Contrast Sensitivity Function improvement during the treatment phase and the retention of this improvement one year post treatment.
NVC Second Generation Applications
The first-generation application (the Amblyopia treatment discussed above) dealt with a visual condition where the “back end” of the visual system—the neurological component—is deficient; however the “front end” of the visual system—the ocular or the optical component—is optimal by nature or by using corrective lenses. The visual perception is limited by the defective or sub normal neurological component. The aim of that treatment is to improve the functionality of the deficient neural system as close as possible to normative level in order to improve vision.
The second-generation applications deal with a different situation, namely with subjects having sub-optimal ocular conditions; however their neuronal connectivity is developed normally and is capable of processing images relatively efficiently. In those visual conditions the visual input is subnormal and limited by the ocular “front end” of the visual system.
The aim of this treatment is to further enhance the neurological component functionality beyond the normative range in order to improve the neuronal S/N ratio, which leads to improved contrast sensitivity, and thereby to improved visual acuity. Improving one's contrast sensitivity function simply means improving its ability to see more sharply.
The ability to improve contrast sensitivity by enhancing the efficiency of the neural processing makes the treatment also applicable to improving visual acuity under disparate conditions, such as Myopia, Presbyopia, Hyperopia. Other possible applications include residual refractive errors in Post-refractive surgery subjects and other eye diseases causing reduced vision, such as glaucoma or age-related macular degeneration (AMD).
Another possible application is in reducing the progression of myopia in children. This condition appears to be directly linked to visual images presented during the early years of life. Animal models of myopia have clearly established that a blurred visual image (either from occluding the eye, or from inducing refractive errors with lenses) directly results in abnormal eye growth, often resulting in an extremely elongated eyeball, resulting in high myopia. It therefore follows that if visual perception can be enhanced or sharpened in a developing myopic eye in childhood, there is a possibility that this may break the positive feedback loop, and myopia progression may be reduced significantly.
Myopia Treatment Principles
In Myopia, the neuronal connectivity is developed normally and is capable of processing images relatively efficiently; however the visual input is subnormal and limited by optics. The visibility of mid and high spatial frequencies is perceived as low contrast even when their physical contrast is high. Thus, CSF is reduced at the high spatial frequencies, resembling the amblyopic CSF, which as a consequence, degrades visual acuity (VA). FIG. 12 illustrates the reduced uncorrected CSF in myopic patients.
Activation of neurons in the visual cortex is directly related to signal strength (contrast). When the effective contrast is low, neurons are weakly activated, resulting in low S/N ratio at the respective spatial frequencies. A low S/N ratio is shown to limit performance on letter identification.
As blurred vision results from sub-optimal activity of the neurons vis-á-vis current optics, the Low Myopia treatment aims to improve the S/N (Signal to Noise) ratio, further improve the lateral interactions, and enhance the CSF in particular at Mid-High spatial frequencies.
This is mainly achieved through Visual Perception Tasks (VPTs) focusing in increasing of the lateral excitations.
Increasing Facilitation
The zone of facilitation receives high attention. Practicing the lateral interactions leads to an increased range of those interactions. Treatment focuses in increasing the facilitation level at Target-Flankers separation distance of 2-4 wavelengths. Visual perception tasks at the said Target-Flankers separation distances are repeated to allow further perceptual learning. FIG. 13 illustrates enhancing lateral interactions in myopic patients.
The Trained Eye
The treatment is either binocular or uniocular. A decision is taken according to the uncorrected visual acuity of both eyes and the respective best corrective refraction. This decision is re-evaluated in the course of treatment. The preference is to train binocularly. However when the normalized uncorrected visual ability difference between the eyes exceeds the limit that allows binocularity, then the stronger eye will only be active by default. Therefore, in such cases, when aiming to train the weaker eye, the stronger eye will be covered with a semi-translucent lens and the weaker eye is trained uniocularly.
The Trained Eye Might Change in the Course of Treatment:
1. From binocular to uniocular in case of visual acuity changes that increase the visual acuity difference between the eyes to the extent that justifies training the weaker eye.
2. From uniocular to binocular in case that the visual acuity difference between the eyes has decreased to a limit that allows binocularity or when vision improvement in the weaker eye has exhausted.
3. From uniocular to uniocular—mainly in the case of relatively high astigmatism.
Training Glasses with Reduced Refractive Correction
For optimal improvement, the achieved contrast thresholds at any configuration (spatial frequency, orientation, exposure duration) should enter into a contrast funnel. As Myopes suffer from blurred distance vision (when uncorrected or under corrected), many patients might exceed the effective contrast funnel for various spatial frequencies and orientations.
In order to keep the contrasts within the required range, the patients are preferably provided with training glasses with reduced refractive correction.
The refraction value of the training glasses is determined according to the training eye decision (left, right or both eyes), the uncorrected visual acuity in the respective eyes and patient's refraction. This decision may be changed in the course of treatment based on the achieved contrast levels.
The provided training glasses refraction would be any value between zero and the subject's best refractive correction at, but not limited to the interval of 0.5 diopter (D). For example a subject with refractive error of −1.75D might be given training glasses of −1.5D or −1.0D or −0.5D or no refraction at all.
Spatial Frequency
Through the personalized treatment sessions, the size (spatial-frequency) of the stimuli is changed, starting with lower spatial-frequencies and progressively moving to the higher ones.
The trained spatial frequencies are selected according to the level of subnormality, which is measured during the computerized evaluation. Myopes often suffer from subnormal contrast sensitivity in mid to high special frequencies, when using partial refraction correction or when uncorrected.
Repetitions of the same spatial frequencies are applied in order to stabilize the achieved perceptual learning, and in accordance to performance.
Spatial frequency also depends on the eye swap management. For example, when swapping from binocular to uniocular training, high spatial frequencies would be reduced to lower spatial frequencies.
Orientation
At each spatial frequency the patient is trained at various orientations. Whereas in the first generation application the subject is trained using the best refractive correction such that optical astigmatism is neutralized, here the trained orientations are selected according to the level of meridional subnormality.
If no astigmatism exists, the trained orientations would be 0, 45, 90 and 135 degrees. However in the presence of astigmatism, the astigmatic zone is gradually approached, starting with easier orientations and progressing towards the distortion area. At each spatial frequency, six orientations or even more may be involved. For example, a subject with astigmatism at 90 degrees might be trained in the following order: 0, 135, 45, 60, 75, 90, or 0, 45, 135, 105, 75, 90, or similar.
Low Myopia Treatment Clinical Results
Test have been conducted according to the above-described second-generation applications in the treatment of subjects having Low Myopia or low degrees of refractive errors. Low Myopia is defined as spherical refraction up to −1.5DS (Spheric Diopter) and astigmatism up to −0.5DC (Cylinder Diopter).
Low myopia affects over 100 million worldwide. The prevalence of low myopia is higher among the Chinese population. In Singapore, Hong Kong and Taiwan, over 80% of the population are myopic, and over 30% of the population fall within the Low Myopia definition.
The efficacy of the low myopia treatment has been proven in two pre-clinical studies. The treatment has been tested on adults (aged 17 to 55) having spherical equivalence ≦1.50DS of myopia in their worst eye, and ≦0.50DC of astigmatism in either eye, and Uncorrected VA baseline vision ≦20/100 in their worst eye.
The Clinical Trial Success Criteria are as Follows:
1. For Baseline UCVA<=20/32, end UCVA<=20/20.
2. For Baseline 20/32<UCVA<=20/63, end UCVA<=(Baseline-2 ETDRS lines).
3. For Baseline 20/63<UCVA<=20/100, end UCVA<=20/40. in a minimum of 60% of completed subjects.
The Following are the Highlights of the Study Results:
1. The success rate was 79.5% (27 out of 34 eyes).
2. The average visual acuity improvement was 2.7 ETDRS lines.
3. 55% of the treated eyes reached 20/25 vision or better, while 35% improved to 20/20 vision or better (“super-normal vision”).
4. The contrast sensitivity function (CSF) improved remarkably and significantly. The uncorrected CSF average—after treatment was well within the normal range.
FIG. 14 presents the individual Uncorrected Visual Acuity improvement of all treated eyes. FIG. 15 presents the treatment group average CSF (contrast sensitivity function) improvement during the treatment phase.
Following are the main differences between the First and Second Generation Applications:
Subject Second Generation First Generation Deficient Ocular component Neurological component visual perception component Eye Swap Exists. Does not exist. Management Trained eye might be Only Amblyopic eye Left, Right or Both eyes. trained Changes as the treatment progresses Training Exists Does not exist Glasses Training glasses with Best Refractive Management reduced refraction are correction for used. Amblyopic eye during Refraction may change as the entire treatment. the treatment progresses Inter-dependency Exists Does not exist between Spatial frequency changes trained eye, in accordance with the training change in trained eye or glasses the change in training refraction and glasses refraction VPT spatial frequency Lateral Increasing Facilitation Reducing Suppression Masking VPT focus Spatial Does not Exist Exists Localization VPT Effective Training glasses Gabor patches elongation Contrast Funnel management and increase in exposure maintained duration. through Orientation Up to six or more Four main orientations: Selection orientations, depending on 0, 45, 90, 135 Astigmatism level and axis.
Contrast Funnel
The term “Contrast Funnel” refers to the desired range of contrast levels a patient is expected to achieve in order to gain optimal vision improvement while undergoing NeuroVision treatment.
This range of contrasts (defined as Minimum contrast and Maximum contrast) depends on a series of parameters:
1. The patient's eye condition that we are aiming to improve 2. The normative values—the values a subject with normal vision would achieve in a similar task 3. The VPT spatial frequency 4. The VPT orientation 5. The VPT exposure duration 6. The training glasses used 7. The training mode—Binocular or Uniocular
For example, the optimal contrast ranges for diagonal orientations are higher than those for vertical and horizontal orientations.
The treatment algorithms would adjust the treatment sessions parameters in order to allow the individual patient achieve the desired contrast levels within the funnel.
A Preferred Hardware and Software Implementation
FIGS. 16-21 illustrate a preferred hardware and software implementation of the invention as described above.
The hardware implementation illustrated in FIG. 16 includes a host server 800 and a client terminal 820 . Host server 800 is typically a computer system 802 on a network with server software 801 configured to receive and answer requests for information. Typically, computer system 802 is also dedicated to storing data files and managing network resources, including network traffic. Computer system 802 generally includes a processor 804 and a data storage device 806 , and is typically connected to a global communication network, such as the Internet 840 .
Host server 800 , through processor 804 , has access to software 808 comprising sequences of instructions that cause processor 804 to perform a number of acts in accordance with the preferred methods described herein. Host server 800 also has access to a client database 812 that stores information concerning persons of the system. This information can include identification information and data relating to a person's performance during past VPT Sessions. Client database 812 may reside outside host server 800 , such as at client terminal 820 .
Client terminal 820 is a remote terminal that provides an interface for a person to access host server 800 . Client terminal 820 is typically a computer system 822 communicatively coupled to host server 800 by a communication network, such as the Internet 840 . Computer system 822 generally includes a processor 824 , a data storage device 826 , a display screen 828 , an input device 830 , and software comprising sequences of instructions that cause processor 824 to perform a number of acts in accordance with the methods described herein.
FIG. 17 is a flowchart depicting a preferred implementation of how the method is carried out at host server 800 . Starting with step 900 , host server 800 first receives a request from client terminal 820 for access to a VPT Session. This request is sent from client terminal 820 to host server 800 over a communication network, such as the Internet 840 .
In step 902 , an authentication routine is performed to determine whether the request from client terminal 820 is valid. Generally, host server 800 does this by sending a request over the Internet to client terminal 820 for a username and password. In step 904 , upon receiving the username and password data from client terminal 820 , host server 800 compares that data to username and password data stored in client database 812 . If host server 800 determines that the person is authentic, the process continues to step 906 . If the person is deemed to be non-authentic, a message is sent to client terminal 820 informing the person that access to the VPT Sessions is denied, as shown in step 918 . At that point, the person may be allowed to re-enter his or her username and password information a number of times.
In step 906 , after host server 800 determines that the username and password supplied are genuine, a VPT Session is selected and an initial set of VPT Session parameters are generated. Typically, these parameters are defined in advance. The VPT Session is selected according to the methods described below, and the VPT Session parameters are generated as explained below with reference to step 916 . The VPT Session parameters define items such as contrast level, contours, spatial frequency, distance between objects, target placement, local and/or global orientations, and presentation time for each of the VPTs and VPT Images 100 being used to test or improve the visual perception process of a person.
In step 908 , the initial VPT Session parameters are delivered to client terminal 820 over the Internet 840 . Software resident on client terminal 820 is configured to receive the VPT Session parameters and use them to dynamically generate VPT Images 100 and VPTs. Once the parameters are delivered, the VPT Session can be carried out solely at client terminal 820 without the need for further interaction with host server 800 . This preferred configuration allows the VPT Session to be administered to the person without delay or interruption.
In step 910 , after the VPT Session has been administered to the person, host server 800 receives a set of person performance data from client terminal 820 . The person performance data is data relating to the person's performance, which primarily comprises the stabilized values generated for each series of VPTs administered during a VPT Session. It can also include some or all of the user inputs received by client terminal 820 . The person performance data is generated by client terminal 820 and is then sent back to host server 800 over the Internet 840 .
In step 912 , host server 800 stores the person performance data it receives from client terminal 820 .
In step 914 , host server 800 analyzes the person performance data to reveal any visual perception deficiencies, and to determine the level of performance of the person's visual perception process. Software 808 provides instructions and data for processor 804 to carry out this analysis. This is done by comparing the person performance data to data collected from persons with “normal vision,” i.e., based on generally acceptable levels of performance for each of the different aspects of the visual perception process; this helps gauge the person's level of performance. Processor 804 performs this comparison, using data related to that of a “normal observer,” which is stored in data storage device 806 .
In step 916 , new VPT Session parameters are generated for use in the next VPT Session, based at least in part upon the person performance data received by host server 800 , and upon the analysis conducted on the person performance data by processor 804 . These new parameters again define specific VPT Images 100 and VPTs to further improve the person's visual perception ability based upon the person's level of performance.
Further particulars of the hardware illustrated in FIG. 16 , and the operations of the flow chart of FIG. 17 , as well as many variations and modifications, are more particularly described in the above-cited U.S. patent application Ser. No. 169609 filed Nov. 13, 2002, published Jun. 12, 2003 as U.S. Patent Application 2003/0109800, the contents of which are incorporated herein by reference.
FIG. 18 illustrates a preferred method of determining the selected VPT session. The flow chart illustrated in FIG. 18 is similar to the flow chart ( FIG. 10 ) in the above-cited published U.S. patent application Ser. No. 169609, except that, before the initial evaluation has started (steps 950 , 952 ), a determination is made as to the type of training glasses to be applied to the patient during the treatment (steps 954 , 956 ). As described earlier, training glasses with reduced refraction for the respective eye are applied to the one or both eyes being treated, particularly when the eye condition being treated is myopia, with or without astigmatism. Thus, in order to keep the contrasts within the desired range, the patients would be provided with training glasses with reduced refractive correction.
As also described earlier, not only is the type of training glasses determined, but also the training eye is determined. During the treatment, eye swapping may be effected wherein the trained eye is changed to the left eye, the right eye, or both eyes. There is a logical dependency between the change of the training eye, the training glasses, and the spatial frequency. When the training eye is changed, the training glasses, as well as the spatial frequency, may also be changed.
The remaining operations illustrated in the flow chart of FIG. 18 are basically the same as described in the above-cited published Patent Application ( FIG. 10 ).
Thus, as described therein, there are two forms of VPT sessions available: an evaluation phase to ascertain a person's visual perception ability, and a treatment phase to improve the person's visual perception. Accordingly, as shown in step 1000 , the first step in selecting a VPT Session is to determine whether the person has undergone the evaluation phase. If an evaluation has not been completed, the next step in the process is to move on to step 1002 . Otherwise, the flowchart will continue at step 1010 .
Starting with the evaluation phase and step 1002 , a person undergoes an evaluation to ascertain the condition of the person's visual perception process. This data allows generation of effective VPTs that target the person's visual perception deficiencies. It also allows for a baseline set of data to gauge whether the person's visual perception is improving over the course of a particular VPT Session and over time. The evaluation process can be performed as often as necessary or desired.
In step 1004 , the user inputs and performance data from past VPT Sessions are analyzed. This data provides information that is useful for establishing parameters that select VPT Images 100 and VPT Sessions to use to evaluate the person's visual perception.
In step 1006 , a VPT Session is selected from a first group of potential VPT Sessions. VPTs within each VPT Session are used to collect data from the person regarding different aspects of the person's visual perception process to detect the existence of any physical or neural defects.
In step 1008 , once the VPT Session has been selected, parameters for the VPT Session are generated. These parameters define the VPT Images that are to be presented to the person, and in particular control the difficulty of the VPTs as well as other characteristics.
In step 1010 , a treatment phase is initiated for improving various aspects of the visual perception process of a person and alleviate visual perception deficiencies. The flow of the treatment phase is almost identical to that of the evaluation phase. In step 1012 , the user inputs from past VPT Sessions are analyzed. In step 1014 , a VPT Session is selected from a second group of VPT Sessions. This second group of VPT Sessions is different than the group described for the evaluation phase. In step 1016 , parameters are generated which again define the VPT Images that are to be presented to the person.
FIG. 19 is a flow chart illustrating the operations involved in the analysis of an evaluation session. Three such evaluation sessions are illustrated.
In the first evaluation session, a determination is made of the starting size/spatial frequency (step 1110 ), and of the starting exposure duration (step 1112 ). A determination is then made of any changes required in the refraction of the training glasses (step 1114 ). The foregoing operations are repeated if the data is not complete (step 1116 ).
In the second evaluation session, a determination is made of the main orientations order (step 1120 ), of the worse orientation slice (step 1122 ), and of any additional required orientations (step 1124 ). A determination is then made whether any changes are required in the refraction of the training glasses ( 1126 ). If the data is not complete, the foregoing operations are repeated (step 1128 ).
In the third evaluation session, any missing data is completed (step 1130 ), and a determination is made as to any additional required parameters ( 1132 ).
FIGS. 20 and 21 illustrate the operations involved in analyzing a treatment session. Thus, the first operations are to calculate the normalized achieved contrast (step 1200 ), the facilitation at each mask distance (step 1202 ), and the total and optimal range facilitation (step 1204 ). A determination is then made as to whether the normalized contrast is satisfactory (step 1206 ). If not, a determination is made as to whether the normalized contrast is within the desired funnel (step 1208 ), and if not, the refraction of the training glasses is appropriately increased or decreased (step 1210 ).
On the other hand, if in operation 1206 the normalized contrast was found to be satisfactory, a determine is made as to whether the facilitation and optimal facilitation are satisfactory (step 1212 ). If not, the same state is repeated (step 1214 ), but if so, the program proceeds to the next state (step 1216 ).
As seen in the flow chart of FIG. 21 , after the foregoing operations have been performed in a treatment session, a determination is made as to whether the visual acuity has changed or whether the last orientation was done (step 1220 ). If not, the analysis is completed, but if so, the trained eye is re-determined based on the new visual acuity (step 1222 ), of any required changes in the refraction of the training glasses (step 12224 ), and of the state, i.e., spatial frequency, orientation, exposure (step 1226 ).
The foregoing operations are performed until the desired “contrast funnel” is achieved, i.e., the desired range of contrast levels a patient is expected to achieve in order to gain optimal visual improvement while undergoing the foregoing treatment
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents, patent applications and sequences identified by their accession numbers mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent, patent application or sequence identified by their accession number was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. | A method of improving the visual perception ability of a person by: displaying to the person in at least one evaluation sessions a plurality of images selected to test the visual perception ability of the person with respect to a visual defect, and to elicit responses from the person indicative of the level of the person's visual perception ability with respect thereto; and by utilizing the responses to select another plurality of images designed to treat the person with respect to a detected visual defect; applying training glasses with reduced refraction for the respective eye, and displaying to person another plurality of images in treatment sessions until the visual perception ability of the person has been improved. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage filing under section 371 of International Application No. PCT/FR2008/050520 filed on Mar. 26, 2008, and published in French on Nov. 6, 2008 as WO 2008/132409 and claims priority of French application No. 0754340 filed on Apr. 6, 2007, the entire disclosure of these applications being hereby incorporated herein by reference.
FIELD OF THE INVENTION
The object of the invention is a lithium oxynitride ion sputtering target. It also relates to a method for making an electrolyte in the form of a lithium oxynitride thin film from said target. It relates lastly to an electrochemical device comprising a substrate provided with said electrolyte.
PRIOR ART
Electrochemical devices such as all-solid micro-batteries, electrochromic devices or micro or super capacitors comprise an electrolyte membrane that comes in the form of a thin mineral film between 1 and 2μ thick, the film being vacuum deposited by cathode sputtering from a target.
Currently used targets are of the oxide type such as for example lithium phosphate (Li 3 PO 4 ), lithium silicate (SiO 4 ) lithium borate (LiBO 2 ), lithium sulphate (Li 2 SO 4 ) and are generally sputtered in pure nitrogen thereby improving the electrochemical performance.
Nonetheless, apart from the good electrochemical performance obtained, problems have to be faced, if said methods are to be industrialized, in terms of the deposition rate, conductivity and mechanical properties of the thin films.
To take the deposition rate first, this is at best generally about 1 μm per hour. In particular, the document U.S. Pat. No. 5,338,625 describes a method for manufacturing LiPON thin films by RF magnetron cathode sputtering using a Li 3 PO 4 target in nitrogen. Deposition rates are obtained of between 0.8 and 1 nm per minute, which is still incompatible with any potential industrialization.
The possibility is known from the document U.S. Pat. No. 4,428,811 of obtaining high deposition rates in excess of 100 μm per minute, but of metal nitride such as titanium, zirconium and hafnium nitride deposited by reactive cathode sputtering of titanium, zirconium and hafnium targets respectively in an argon/nitrogen mixture. In said document the thin films obtained are not oxynitrides but nitrides, but they are however depositions produced in reactive mode in nitrogen by magnetron cathode sputtering which illustrate the possibility of obtaining high deposition rates via this technique.
The document Scripta materials 42 (2000) 43-49 describes the implementation of a Li 3 PO 4 +Li 3 N molar composition target to obtain a thin film of lithium oxynitride. In practice, the target is sputtered in nitrogen at high power densities of between 2 and 5 watts per cm 2 . Under these conditions, the deposition rate remains low, at less than 5 nm per minute at 5 watts per cm 2 .
The HAMON thesis “Nitridation of vitreous ionic conductors in thin films” defended on 9 Jul. 2004 mentions that the rate of deposition of a Li oxynitride thin film from an Li 3 PO 4 target is in practice between 1 and 6 nm per min whereas the rates needed to industrialize the method would be at least of the order of 30 nm per min, i.e at least 5 times higher.
This same document further states that the ionic conductivity of thin films is reduced substantially when the deposition rates are increased.
The HAMON thesis lastly stresses the lack of consistency in the mechanical properties of thin films obtained from one sample to the next.
DISCLOSURE OF THE INVENTION
The problem that the invention sets out to resolve is therefore that of developing a target that can be used to industrialize the method of depositing metal oxynitride thin films by ion sputtering at a deposition rate above 30 nm per min while obtaining maximum conductivity for a given material and improved mechanical properties for the thin film obtained.
To do this, the Applicant has perfected a new cathode sputtering metal oxynitride target comprising:
between 30 and 40 atomic % of a metal, particularly lithium; between 2 and 10 atomic % of nitrogen; between 35 and 50 atomic % of oxygen, the remainder up to 100% being constituted by at least one element selected from the group that comprises phosphorous (P), boron (B), silicon (Si), germanium (Ge), gallium (Ga), sulphur (S) and aluminium (Al).
For an atomic lithium concentration [Li]<30%, the ionic conductivity of thin films is too low. For an atomic lithium concentration [Li]>40%, thin films frequently have growth defects that render them unsuitable for use as an electrolyte, particularly at a deposition rate in excess of 1 μm per hour.
Likewise, for an atomic nitrogen concentration [N]<2%, the ionic conductivity of the thin films obtained is too low for work at deposition rates in excess of 1 μm per hour. For an atomic nitrogen concentration [N]>10%, the state of stress of the thin films obtained is too high for work at deposition rates in excess of 1 μm per hour.
Lastly, for an atomic oxygen concentration [O]<35%, either the electrochemical stability, or the ionic conductivity of the thin films obtained, is too low. For an atomic oxygen concentration [O]>50% the ionic conductivity of the thin films obtained is too low.
In one advantageous embodiment, the total atomic concentration in the target of the element or elements selected from the group comprising phosphorous (P), boron (B), silicon (Si), germanium (Ge), gallium (Ga), sulphur (S) and aluminium (Al) is between 10% and 25%., and to advantage between 12% and 20%.
To advantage, the target further contains phosphorous and/or boron and/or silicon.
In a preferred embodiment, the atomic lithium concentration is between 33% and 38%, the atomic nitrogen concentration is between 4% and 8% while the atomic oxygen concentration is between 40 and 45%.
The target may contain impurities that may either come from the start components used in the manufacture thereof, or be incorporated at the time of said manufacture. In practice, the impurities represent less than 2% molar of the target. At said rate, no substantial alteration is observed in the properties of the materials obtained.
In practice, the target may come in the form of a homogeneous glass or be formed of homogeneous grains or grains of a different type evenly distributed in the target.
The preferred inventive targets have the following chemical formulae: Li 3 P 1 O 3,1 N 0.6 ; Li 2.5 P 0.5 Si 0.5 O 2.6 N 0.6 ; (Li 3 PO 4 ) 0.6 (B 2 O 3 ) 0.2 (Li 3 N) 0.3 .
A further object of the invention is a method of manufacturing a metal-oxynitride-based thin film by the magnetic-field-assisted cathode sputtering in reactive oxidizing atmosphere of a target, as previously described.
According to another feature of the method, the reactive atmosphere may be constituted by a gas such as pure nitrogen or a mixture of gases, and particularly a nitrogen/argon mixture.
According to another feature, the sputtering is carried out at a power density of between 0.5 W/cm 2 and 5 W/cm 2 .
A further object of the invention is an electrochemical device such as for example a micro-battery, an electrochromic device or a micro super capacitor comprising an electrolyte in the form of a thin film obtained using the method previously described.
The invention and the resulting advantages thereof will become clearer from the embodiment examples given hereinafter.
DETAILED DESCRIPTION OF THE INVENTION
All the examples relate to targets that respect the chemical formula Li X AO Y N Z , A being composed of at least one of the elements P, Si, B with [A]=[P]+[Si]+[B]. The values x, y and z represent the atomic concentrations of Li, O and N.
The targets in examples 1a, 2a and 3a are in accordance with the inventive targets. The targets in examples 1b, 2b and 3b, and 6 are examples showing prior art targets and targets 4 and 5 non-conforming targets.
The formulae of the different targets tested are reproduced in the table below:
Atomic Concentration
30% ≦
2% ≦
40% ≦
[Li] ≦
[N] ≦
[O] ≦
10% <
40%
10%
50%
[A] < 25%
Example 1a in conformity
39%
8%
40%
13%
Target Li 3 P 1 O 3.1 N 0.6
Example 1b non-conforming
38%
0%
50%
13%
Target Li 3 PO 4
Example 2a in conformity
37%
7%
40%
14%
Target Li 2.5 P 0.5 Si 0.5 O 2.6 N 0.6
Example 2b non-conforming
36%
0%
50%
14%
Li 2.5 P 0.5 Si 0.5 O 3.5
Example 3° in conformity,
39%
4%
43%
15%
target
(Li 3 PO 4 ) 0.6 (B 2 O 3 ) 0.2 (Li 3 N) 0,3
Example 3b non-
34%
0%
50%
15%
conforming, target
(Li 3 PO 4 ) 0.6 (LiBO 2 ) 0.4
Example 4 non-conforming
34%
13%
38%
16%
Target Li 2.2 P 1 O 2.4 N 0.8
Example 5 non-conforming
21%
8%
50%
21%
Target Li 1 P 1 O 2,4 N 0.4
Example 6 non-conforming
50%
8%
33%
8%
Target Li 3 PO 4 + Li 3 N
EXAMPLE 1a
A sputtering target of homogeneous composition Li 3 P 1 O 3.1 N 0.6 in conformity with the invention is sputtered by high-frequency magnetron cathode sputtering of a 50/50 Argon/Nitrogen gaseous mixture at 0.8 Pa of pressure at a power density of 4 W/cm 2 and with a distance of 10 cm from target to substrates. A deposition rate of 4 μm per hour is obtained for a vitreous thin film of homogeneous appearance with the composition Li 2.8 P 1 O 3 N 0.6 whereof the lithium ion conductivity at ambient temperature is 2.5 E-6 Scm −1 . A 1.5 μm thick film of this electrolyte is perfectly satisfactory for its insertion into a lithium micro-battery
EXAMPLE 1b
A sputtering target of homogeneous composition Li 3 PO 4 , not in conformity with the invention, is sputtered by high frequency magnetron cathode sputtering of pure nitrogen at 0.8 Pa of pressure at a power density of 4 W/cm 2 and with a distance of 10 cm from target to substrates. A deposition rate of 3 μm per hour is obtained for a thin film that is vitreous over a part of its surface and of matt appearance in places. The thin film has a composition Li 2.6 P 1 O 3.6 N 0.1 and its lithium ion conductivity at ambient temperature is 0.3 E-6 Scm −1 . The areas where the thin film is of matt appearance appear granulated under the microscope, and are totally unusable as an electrolyte. The conductivity obtained at this power density starting from such a target is about three to four times lower that what might be hoped for with this material and on the other hand the growth of the thin film formed under said conditions is not conducive to reliable industrial production since significant areas of the thin film present columnar growth unsuitable for its use as an electrolyte in a micro-battery, an electrochromic device or a super capacitor.
EXAMPLE 2a
A sputtering target of homogeneous composition Li 2.5 P 0.5 Si 0.5 O 2.7 N 0.5 in conformity with the invention is sputtered by high frequency magnetron sputtering of a 50/50 argon/nitrogen mixture at 0.6 Pa of pressure at a power of 3.5 W/cm 2 and with a distance of 10 cm from target to substrates. The deposition rate obtained is 3 μm per hour and a vitreous thin film is obtained of homogeneous appearance and of composition Li 2.4 P 0.5 Si 0.5 O 2.2 N 0.8 with lithium ion conductivity at ambient temperature of 12 E-6 Scm −1 . A 1.5 μm thick film of this electrolyte is perfectly satisfactory for its insertion into a micro-battery.
EXAMPLE 2b
A sputtering target of homogeneous composition Li 2.5 P 0.5 Si 0.5 O 3.5 not in conformity with the invention is sputtered by high frequency magnetron sputtering of a 50/50 argon/nitrogen mixture at 0.6 Pa of pressure and at a power of 3.5 W/cm 2 with a distance of 10 cm from target to substrates. The deposition rate obtained is 2.5 μm per hour and a vitreous matrix thin film is obtained that comprises small grains included in the film. The average composition of the thin film is Li 2.4 P 0.5 Si 0.5 O 3.3 N 0.1 and its lithium ion conductivity at ambient temperature is 2 E-7 Scm −1 .
This thin film can be used as an electrolyte for micro-batteries, but its conductivity is low for this type of material and the growth of the film shows what could be a phase separation which may well compromise the industrialization thereof
EXAMPLE 3a
A target of molar composition (Li 3 PO 4 ) 0.6 (B 2 O 3 ) 0.2 (Li 3 N) 0.3 obtained by the homogeneous clustering, via a binding agent, of three powders: Li 3 PO 4 ; B 2 O 3 ; Li 3 N. The chemical composition of the target is in accordance with the invention. The target is sputtered by high frequency magnetron cathode sputtering of nitrogen at 0.8 Pa and at a power density of 2 W/cm 2 with a distance of 10 cm from target to substrates. A deposition rate of 2 μm per hour is obtained for a vitreous thin film with the composition Li 2.5 P 0.6 B 0.3 O 2.5 N 0.5 whereof the lithium ion conductivity at ambient temperature is 1.2 E-6 Scm −1 . A 1.5 μm thick film of this electrolyte is perfectly satisfactory for its insertion into a micro-battery.
EXAMPLE 3b
A target of molar composition (Li 3 PO 4 ) 0.6 (LiBO 2 ) 0.4 not in conformity with the invention obtained by homogeneous clustering of the two powders: Li 3 PO 4 ; LiBO 2 is sputtered by high frequency magnetron cathode sputtering of nitrogen at 0.8 Pa at a power density of 2 W/cm 2 and with a distance of 10 cm from target to substrates. A deposition rate of 1.6 μm per hour is obtained for a vitreous thin film with the composition Li 2.2 P 0.6 B 0.3 O 2.9 N 0.1 whereof the lithium ion conductivity at ambient temperature is 4 E-7 Scm −1 . As has been seen in examples 1a and 3a, there is hope, with this type of material, of obtaining thin films with ionic conductivity at ambient temperature about four times better.
EXAMPLE 4
A target of composition Li 2.2 P 1 O 2.4 N 0.8 not in conformity with the invention is sputtered by high frequency magnetron cathode sputtering of nitrogen at 0.8 Pa and at a power density of 2W/cm 2 with a distance of 10 cm from target to substrates. A deposition rate of 2.6 μm per hour is obtained for a vitreous thin film with composition Li 2.2 P 1 O 2.3 N 0.9 whereof the lithium ion conductivity at ambient temperature is 1 E-7 Scm −1 . The thin film obtained has a high state of tensile stress when it is deposited on a substrate of sodocalcic white glass and local delamination can even be observed in the thin film with observation under the microscope thereof confirming its state of tension.
An electrochemical stability test on the thin film shows us an initial deterioration thereof when polarization is applied to it in excess of 4 Volts. By way of comparison, a good material of the same family of composition Li 2.8 P 1 O 3 N 0.6 withstands more than 5V and has no high state of stress. A high deposition rate is actually obtained with this target, but properties compatible with an industrialization of the thin films produced are not obtained.
EXAMPLE 5
A sputtering target of non-conforming homogeneous composition Li 1 P 1 O 2.4 N 0.4 is sputtered by high frequency magnetron cathode sputtering of a 50/50 Argon/Nitrogen gaseous mixture at 0.8 P of pressure and at a power density of 2 W/cm 2 with a distance of 10 cm from target to substrates. A deposition rate of 2 μm per hour is obtained for a vitreous thin film of homogeneous appearance with the composition Li 1 P 1 O 2.3 N 0.4 whereof the lithium ion conductivity at ambient temperature is 1E-8 Scm −1 . A 1.5 μm thick film of this electrolyte can be used for its insertion into a micro-battery for example, but its conductivity is too far from the current standards obtained in example 1a to aspire to the industrialization thereof. | A cathode sputtering target includes: between 30 and 40 atomic % of a metal, between 2 and 10 atomic % of nitrogen, and between 35 and 50 atomic % of oxygen. The remainder up to 100% is constituted by at least one element selected from the group that comprises phosphorous (P), boron (B), silicon (Si), germanium (Ge), gallium (Ga), sulphur (S) and aluminium (Al). Also provides a method of manufacturing a thin film from the target, and an electrochemical device comprising the thin film. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of copending application Ser. Nos. 07/665,698 filed on Oct. 29, 1984 and 07/665,699 filed on Oct. 29, 1984, now issued as U.S. Pat. Nos. 4,474,819 and 4,744,787.
BACKGROUND OF THE INVENTION
This invention relates to methods and apparatus for transdermal medicament delivery and to improvements therein. More specifically, this invention relates to improved methods and apparatus for active (as opposed to passive) transdermal, ambulatory, drug delivery. Yet more particularly, this invention relates to increased efficiency iontophoresis devices or appliances and to improved methods of making and using such devices.
Iontophoresis, according to Dorland's Illustrated Medical Dictionary, is defined to be "the introduction, by means of electric current, of ions of soluble salts into the tissues of the body for therapeutic purposes." Iontophoretic devices have been known since the early 1900's. British patent specification 410,009 (1934) describes an iontophoric device which overcame one of the disadvantages of such early devices known to the art at that time, namely the requirement of a special low tension (low voltage) source of current which meant that the patient needed to be immobilized near such source. The device of that British specification was made by forming from the electrodes and the material containing the medicament or drug to be delivered transdermally, a galvanic cell which itself produced the current necessary for iontophoretically delivering the medicament. This ambulatory device thus permitted iontophoretic drug delivery with substantially less interference with the patient's daily occupation.
More recently, a number of United States patents have issued in the iontophoresis technology, indicating a renewed interest in this mode of drug delivery. For example, U.S. Pat. No. 3,991,755 issued to Jack A. Vernon et al; U.S. Pat. No. 4,141,359 issued to Stephen C. Jacobson et al; U.S. Pat. No. 4,398,545 issued to Wilson; U.S. Pat. No. 4,250,878 issued to Jacobsen disclose examples of iontophoretic devices and some applications thereof. The iontophoresis process has been found to be useful in the transdermal administration or introduction of medicaments or drugs including lidocaine hydrochloride, hydrocortisone, acetic acid, fluoride, penicillin, dexamethasone sodium phosphate and many other drugs. Perhaps the widest use of iontophoresis is that of diagnosing cystic fibrosis by using pilocarpine nitrate iontophoresis. The pilocarpine nitrate stimulates sweat production; the sweat is collected and analyzed for its chloride content to detect the presence of the disease.
In presently known iontophoretic devices, at least two electrodes are generally used. Both these electrodes are disposed so as to be in intimate electrical contact with some portion of the skin of the body. One electrode, called the active electrode, is the electrode from which the ionic substance, medicament, drug precursor or drug is delivered or driven into the body by electrical repulsion. The other electrode, called the indifferent or ground electrode, serves to close the electrical circuit through the body. In conjunction with the patient's skin contacted by the electrodes, the circuit is completed by connection of the electrodes to a source of electrical energy, e.g., a battery, or appropriately modified household current. For example, if the ionic substance to be driven into the body is positively charged, then the positive electrode (the anode) will be the active electrode and the negative electrode (the cathode) will serve to complete the circuit. If the ionic substance to be delivered is negatively charged, then the negative electrode will be the active electrode and the positive electrode will be the indifferent electrode.
Furthermore, existing iontophoresis devices generally require a reservoir or source of the ionized or ionizable species (or a precursor of such species) which is to be iontophoretically delivered or introduced into the body. Examples of such reservoirs or sources of ionized or ionizable species include a pouch as described in the previously mentioned Jacobsen U.S. Pat. No. 4,250,878, or the pre-formed gel body of U.S. Pat. No. 4,383,529 issued to Webster. Such drug reservoirs, when electrically connected to the anode or the cathode of an iontophoresis device to provide a fixed or renewable source of one or more desired species, are generally used with anodes or cathodes which are substantially electrochemically inert. As is more fully discussed below, utilization of such substantially inert electrodes as contemplated in the prior art has significant disadvantages.
The present invention provides enhanced methods and apparatus for the iontophoretic delivery of ionized or ionizable medicaments e.g., drugs, by means of the intentional selection and utilization of a combination of anode or cathode conductive members or electrodes having specified characteristics and the drug(s) to be delivered. Use of this invention increases the efficiency, safety and acceptability of the iontophoretic drug delivery process.
BRIEF SUMMARY OF THE INVENTION
Briefly, in one aspect, the present invention is a method of iontophoretic drug delivery wherein the drug to be iontophoretically delivered, an electrochemically active component of the drug delivery apparatus, or both, are intentionally selected so that during operation of the device, the production of unwanted species is minimized. In another aspect of this invention, the drug to be iontophoretically delivered, an electrochemically active component of the apparatus or both are intentionally selected to reduce the formation of unwanted water hydrolysis products during operation of the device. In yet another aspect of this invention, the drug to be delivered, an electrochemically active component of the iontophoresis apparatus or both, are intentionally selected so as to reduce the presence of water hydrolysis products after they are formed. As contemplated herein, an electrochemically active component of an iontophoresis device is a part of the device which is oxidized or reduced during iontophoretic drug delivery or which oxidizes or reduces other available species.
The present invention also contemplates improved bioelectrodes particularly suited for use with iontophoresis device or appliance. The improved electrode of this invention provides an iontophoretic device which exhibits enhanced coulombic efficiency in drug delivery processes. The electrode comprises a reservoir containing the medicament to be iontophoretically delivered, the reservoir being in electrical connection with an electrochemically active component, e.g., an active current distribution member, the species produced from the electrochemically active component during operation of the device interacting with the counterion of the medicament of the reservoir during iontophoretic drug delivery so as to minimize the formation and delivery of undesired species, the electrochemically active component being in further electrical connection with a source of electrical energy. In a preferred aspect, the electrode includes means to secure the electrode to the skin so as to permit iontophoretic drug delivery therefrom.
In a further aspect, the present invention is a method of iontophoretic drug delivery having enhanced coulombic efficiency comprising the steps of selecting the ionic species e.g., a drug, to be iontophoretically delivered; incorporating the ionic species into an electrode such as in its medicament reservoir; selecting the composition or construction of either the anode or the cathode of the iontophoresis device to include an electrochemically active component so that electrochemical reaction at the anode or the cathode produces species which interact with the ionic species so as to reduce the formation of undesired ions; placing the selected anode or cathode in electrical connection with the ionic species (e.g., in connection with the reservoir) and with a source of electrical energy; and transdermally delivering the selected ionic species into the body while minimizing the formation and delivery of undesired species.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a first iontophoresis electrode according to the present invention.
FIG. 2 is a cross-sectional view of a second iontophoresis electrode according to the present invention.
FIG. 3 is a lower, plan view of the iontophoresis electrode of FIG. 2.
FIG. 4 is a cross-sectional view of a third iontophoresis electrode according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The genesis of this invention was in the realization that known iontophoretic drug delivery processes have an efficiency in the range of about 5% or less and that iontophoretic drug delivery is largely a diffusion dependent process. This means that approximately 95% of the current utilized in known iontophoresis processes is consumed in activities other than delivering the intended drug. For example, much current is wasted by the migration of highly mobile species such as H + , OH - , →Na + and C1 - .
Thus it was realized that iontophoretic drug delivery efficiency would be enhanced if the availability of species which are more mobile than the drug which was to be delivered were minimized. Minimization of the concentration or charge of species which were more easily transported than the intended species (i.e., a drug) is utilized herein to provide enhanced drug delivery. It is the enhanced drug delivery described herein which may permit iontophoresis to become a viable alternative to other drug delivery techniques.
Prior art iontophoretic devices often utilize substantially inert stainless steel, nickel or other nickel and iron alloys as current distribution members or electrodes. During operation of such iontophoretic devices in accordance with prior art iontophoretic drug delivery methods, electrolysis of water occurs. Hydronium (H + ) ions are formed at the anode and hydroxide ions (OH - ) are produced at the cathode. In addition, gaseous hydrogen and oxygen are evolved at the cathode and anode, respectively. (Use of nickel or nickel-containing alloys e.g., stainless steel, also occasionally results in the formation of nickel ions at the anode. The nickel ions are then free to migrate into the drug reservoir of the device and from there into the body.)
Iontophoretic devices which employ such essentially inert electrodes have several inherent disadvantages. First, they exhibit reduced coulombic efficiency of drug transfer (i.e. of charge species) due to the formation of highly mobile hydronium and hydroxyl ions at the electrodes. In addition, such devices evidence instability of pH in the anodic and cathodic reservoirs and adjacent the skin due to the formation of hydronium or hydroxyl ions and gaseous products (hydrogen and oxygen) at the electrodes. Lastly, as noted above, while prior art iontophoretic electrodes are substantially electrochemically inert some undesirable oxidation of e.g., nickel or other alloy metals, does occur.
These disadvantages mean that known iontophoretic devices used according to conventional drug delivery methods have the following drawbacks:
1) Lower coulombic efficiency requires that the battery for a portable or ambulatory device be larger (i.e. of higher capacity). In addition, the voltage required to maintain a certain therapeutic dose rate becomes larger as the coulombic efficiency becomes smaller.
2) The shift in pH in the cathodic and anodic reservoirs, caused by the electrolysis of water, can cause skin irritation, possible degradation the physical properties of the gel components of the device or change the activity of the drug.
3) The formation of hydrogen and oxygen gas at the electrodes can result in a loss of contact between the electrodes and reservoirs leading to reduced device performance.
4) The oxidation of nickel or other metals at the anode results in the contamination of the anodic reservoir with metal ions which then are free to migrate into the skin and body with possible deleterious effects.
It is to overcome these disadvantages and increase the overall efficiency of the iontophoresis process that the present invention was made.
One method contemplated by the present invention for reducing the formation of undesirable or undesired hydronium ions at an electrode and to reduce contamination of the drug reservoir due to the oxidation of electrode metal is to intentionally select an electrode (e.g., an anode) comprising an electrochemically active or sacrificial component which, when oxidized or reduced during operation of the device, produces a species which immediately reacts with ions (e.g., anions) present in the electrode or available to the electrode e.g., in the drug reservoir (which also may be selected, to form an insoluble salt or neutral chemical compound, e.g. H 2 O. "Sacrificial" as that term is used herein means that at least a portion of the electrode (whether anode or cathode) is electrochemically oxidized or reduced during transdermal drug delivery. "Electrochemically active", as the term is used herein, means "sacrificial" as defined above, but includes a material that is not itself oxidized or reduced but which participates in oxidation/reduction. The anion or cation present in the drug reservoir can be present as a separately added material or as the counter-ion to an anionic or cationic drug to be delivered. Illustrating this practice of the invention, the chloride (or hydrochloride) form of a positively charged drug (D + ) would be chosen to be delivered (e.g., by adding it to the reservoir) and the anode would have a silver electrochemically active component which would be sacrificed by oxidation during iontophoresis. The electrochemically generated silver ions would react with the chloride ion in the drug reservoir to form silver chloride. Thus, it is seen that the design of the sacrificial or electrochemically active component of electrode/drug reservoir system can require the selection of an appropriate electrode material, or electrode construction, drug, drug salt or both.
By this expedient, i.e., precipitation of an insoluble species, silver ions and chloride ions are removed from the drug delivery systems and thus are not available to migrate through the reservoir and into the body and therefore the device is more efficient, requiring less battery energy to deliver the drug. The efficiency of delivery of desired species is increased because unwanted species such as Ag + and C1 - are simply removed from the system. Furthermore, production of H + is minimized or avoided thus minimizing pH variation and O 2 production.
In an analogous fashion, if a neutral species is formed from undesired ions (rather than one which precipitates from the system) there is again a net removal of unwanted species since neutral species also would not reduce the efficiency of delivery of charged drug species by migrating in response to electrical currents.
Possible electrode electrochemically active component materials and drug anions for sacrificial electrode devices are numerous, but in general, silver, copper and molybednum metals form insoluble halide salts (e.g. AgC1, AgI, AgBr, CuC1, CuI, CuBr, MoCl 3 , MoI 2 ) and therefore are possible sacrificial anode candidates for delivery of cationic drugs. In addition, ferro and ferricyanides of many metals (e.g., Ag, Sn, Zn, Ni, Mn) are insoluble and therefore combination of these metals with iron cyanide doped reservoirs may provide suitable sacrificial anode/drug reservoir systems. Additional electrodes employing sacrificial anodes would include electrodes having a tin or zinc anode and in which phosphate ions were the counterions to the cationic drug, electrodes having zinc anodes and having oxalate ions as the counterion to the cationic drug and electrodes having copper anodes and citrate ions as the counterions to the cationic drug. As noted above, preferentially, the drug will be compounded with its counterion.
The silver anode/drug chloride sacrificial system is particularly preferred for two reasons. First, silver chloride is highly insoluble and second, many catonic drugs can be purchased in the hydrochloride form which means that the chloride anion in the drug reservoir will be present as the counterion to the drug cation. During operation of an iontophoretic device with a silver anode (e.g., a silver current distribution member) and chloride-containing reservoir, silver is oxidized (Ag→Ag + +e - ) and then reacts with the chloride ion to form insoluble silver chloride near the surface of the silver anode (Ag + +C1 - →AgC1). Simultaneously, the drug cation migrates from the reservoir into the body with greater efficiency than if the oxidation of water to form hydronium ion were allowed to occur at the anode if the anode were substantially inert i.e., it had no electrochemically active component.
An example of a system where the anion in the drug reservoir is present as an additive is the copper/potassium ferrocyanide system. When K 3 Fe(CN) 6 is added to the drug reservoir, FeCN 6 3- anions are formed. By placing the drug reservoirs in contact with e.g., a copper anode, the insoluble salt, Cu 3 Fe(CN) 6 will be formed during device operation. However, unlike the silver/chloride system where the drug cation migrates into the body, in this sytem, potassium ions will be free to migrate from the drug reservoir into the body. Generally speaking, then a further practice of this aspect of the invention would be to employ D x Fe(CN) 6 (x is an integer greater than 0), rather than K 3 Fe(CN) 6 , where it is desired to transport a drug, D+ species through the skin without cationic e.g., K + , competition.
In an analagous practice of this invention, negatively charged, anionic drugs may be more efficiently delivered if an electrochemically active component of the cathode is intentionally selected utilizing the precepts of this invention.
An example of a sacrificial cathode electrochemically active material of this invention is chloridized silver. During device operation, the AgC1 on the surface of a silver cathode is decomposed to give silver metal and chloride anion (AgC1+e - →Ag+C1 - ). The chloride anion is free to migrate, along with any anionic drug, into the body. In this respect, the Ag/AgC1 sacrificial cathode is less efficient than the silver/chloride sacrificial anode in that chloride ion is produced and is delivered to the body. However, the beneficial aspects of the Ag/AgC1 cathode include, (a) no hydrogen gas formation and (b) no hydroxyl anions produced at the cathode.
One skilled in this art will recognize that a sacrificial cathode of this generic type generally comprises a metallic salt in contact with a metal cathode. Furthermore, device operation must result in the decomposition of the metallic salt to form a metal in reduced form plus an anion. If both these conditions are met, in this practice of the present invention, anionic drugs are delivered with mitigation of pH changes.
The use of a sacrificial cathode as herein described in conjunction with an anionic drug specifically selected so that the counterion will react with the anion being produced at the cathode to form an insoluble salt or neutral compound, provides an equivalent method for the control of ion transport as outlined for the anode and anodic reservoir.
Two examples of anionic drug (D - ) which could be intentionally selected for use with an Ag/AgC1 cathode (these drugs would likely be dispersed or dissolved in the ion drug reservoir) are silver or copper salicylate. In this system, chloride ions formed at the cathode are free to react with silver or copper ions in the drug reservoir to form an insoluble salt thus allowing the negatively charged D - anion to migrate into the body without anionic competition.
In yet another method contemplated by the present invention to minimize the formation of hydronium and hydroxide ions which consume current and reduce efficiencies, an intercalation-type cathode or anode is employed. Intercalation electrodes have the property of being capable of absorbing or desorbing alkali metal ions e.g., sodium and potassium, into their structure as the electrodes are oxidized or reduced. Examples of such intercalation compounds would include sodium vanadate and sodium tungstate. The use of intercalation-type cathode or anode materials is particularly advantageous in that the formation of hydroxyl and hydronium ions is minimized along with a decline in the production of hydrogen or oxygen gas.
It is to be recognized that electrodes comprising intercalation-type materials may be used either on the anode or the cathode of the iontophoresis device and thus can deliver either positively or negatively charged drugs. This can be illustrated for sodium tungstate, above, where the anodic reaction would be:
Na.sub.1+x WO.sub.3 →Na.sup.+ +Na.sub.x WO.sub.3 +e.sup.-
For a cathodic reaction,
Na.sup.+ +Na.sub.x WO.sub.3 +e.sup.- →Na.sub.1+x WO.sub.3.
For cathodic electrodes, incorporation of the alkali ion in the drug reservoir would be required. Preferably, this is accomplished by compounding the anionic drug with the alkali metal ion as its counterion. Other suitable intercalation type materials may include graphite, beta alumina, organometallic compounds, transition metal dichalcogenides, prussian blue, polyaniline, polypyrrole, and polyacetyline.
In another practive of the present invention, an intercalation-type electrode may be combined with a segmented reservoir to provide an electrode which provides a more even current distribution and minimizes the possibility of iontophoretic burns. FIG. 2 illustrates the side view of such an electrode. The electrode 40 includes a conductive member 42 which has on its surface an intercalation-type compound 44. This compound is in contact with the drug containing gel 46 located in individual compartments within the electrode, separated from each other by walls or dividers 48, which prevent any substantial horizontal ionic migration. FIG. 3 shows a bottom plan view of the electrode of FIG. 2, illustrating how the walls 48 divide the drug containing gel 46 into different isolated compartments.
Intercalation-type compounds have two particular benefits in conjunction with the compartmentalized electrode. First, the rate of intercalation of ions into or out of the intercalation compound limits the current flow and thus sets a maximum current density. The rate of intercalation into or out of the electrode may be controlled by the type of polymer chosen for the drug reservoir and by the polymer morphology. In addition, after a predetermined number of ions have intercalated into or out of the intercalation compound in a particular area, the compound polarizes and becomes non-conductive in that area. In conjunction with a segmented electrode, this results in an automatic shut off of the current flow through the compartment or compartments in that area, after a predetermined amount of current flow.
The compartmentalized reservoir illustrated in FIGS. 2 and 3 is also believed useful in conjunction with the combinations of current distributing members and ionic drugs described elsewhere in the present application. Use of intercalation-type compounds in the absence of the compartmentalized reservoir is also believed beneficial, as discussed above. However, combining the two is believed to provide a significant additional benefit which neither of the two elements individually can provide.
In the absence of the compartmentalized electrode, use of an intercalation compound will still limit the total overall current flow, but horizontal migration of the ions through the gel could still result in hot spots. Use of highly resistive gel for the drug reservoir would permit limiting the overall current density, but at the expense of battery life. The compartmentalized reservoir alone would prevent substantial horizontal migration of ions, but still would allow hot spots to form in individual compartments limited only by the resistance of the reservoir gel. The combination of the intercalation-type electrode with the compartmentalized reservoir allows for the use of a low impedance polymer gel to prolong battery life while retaining the ability to shut off areas of the electrode having unduly high current density and thereby avoid iontophoretic burns.
A compartmentalized electrode designed similar to that illustrated in FIGS. 2 and 3 is particularly beneficial when combined with a compartmentalized sacrificial electrode. FIG. 4 shows a cross section of such an electrode 50. The electrode 50 is provided with a multiplicity of individual electrode compartments, separated by compartment walls 52, which are impermeable to the passage of ions. Within each compartment is located the drug reservoir gel 54, containing the ionic drug to be delivered. The electrode is provided with a conductive current distribution member 56, which is adapted to be coupled to a source of direct electrical current via electrical connector 58. An insulative backing 60 covers the current distribution member 56. Within each compartment is located a sacrificial electrode material. For example, in systems for delivery of a positive drug, this may be a silver mesh or foil coating 62, applied to the current distribution member 56. It is important to note that the sacrificial electrode material 62 is compartmentalized within the individual electrode compartments, and does not extend from one compartment to another.
An electrode fabricated in this fashion, has an effect similar to that accomplished by the combination of intercalation compound with a compartmentalized electrode discussed above in conjunction with FIGS. 2 and 3. In the case of an electrode adapted to deliver a positive drug, the electrode would operate as follows. The cationic drug (D + ) is compounded in its chloride form, within the individual gel compartments 54. If one of the compartments experiences excessively high current drain, for example due to a breach or flaw in the skin in contact with that cell, the current flowing through that compartment would convert the sacrificial silver 62 to silver chloride more quickly than in surrounding cells. After the silver is completely converted to silver chloride, the current through that compartment would decrease substantially. This reduction in current flow is believed beneficial in avoiding iontophoretic burns, which might otherwise occur in the area of the breach or flaw in the skin.
In yet another practice of the instant invention in which the overall coulombic efficiency of a given iontophoretic drug delivery device is enhanced, a metallic or amalgam electrode is employed optionally in conjunction with the addition of specific metal cations to the drug reservoir i.e., optionally with selection of a drug having a specific metal cation. In this context, lead, mercury and mercury/cadmium amalgams may be used in cathodic electrodes. In this practice of the invention amalgam electrode is consumed during electrochemical discharge of the device, and it reacts with a species intentionally made available to the electrochemical oxidation/reduction product of the amalgam, e.g., by adding a selected drug to the system such as in the drug reservoir. Thus, as in the context described above, the amalgam material herein described is electrochemically reacted and undesired, highly mobile, charged species are consumed or removed. As with the intercalation-type cathode materials discussed above, the production of hydroxyl and hydronium ions during electrochemical discharge also is reduced. Again pH stability is obtained, thus increasing the overall stability and efficiency of the drug delivery device.
In yet a further method for preventing the formation of hydroxyl ions and hydrogen gas at the cathode is to intentionally select an anionic drug whose counterion is an easily reducible metal such as silver or copper. During operation of a device whose reservoir contains such a metal species, the metal ion is reduced to form the neutral metal and the drug anion is free to migrate and carry charge toward the anode. To generalize, any reducible metal form of the anionic drug of interest may be selected. The metal ion of the drug is reduced to a neutral species, i.e., it is plated out or effectively immobilized, and the drug anion is free to migrate and carry charge toward the anode and into the body.
To this point, the present invention has been described in terms of specific selection of drugs or electrode materials so that the formation of water hydrolysis products (and the problems thereby created) are minimized. However, the present invention is not limited to electrode material/drug selections where electrode component is electrochemically oxidized or reduced during operation of the iontophoresis device. The method of this invention may be practiced with presently available "inert" electrodes if it is realized that their efficiency may be significantly enhanced by the judicious, intentional selection of the drug to be delivered.
Generally speaking, the use of inert electrodes to deliver drugs is accomplished by selecting either the basic e.g., (OH - or amine) or acid (H + ) form of the drug to be incorporated into the reservoir, depending upon whatever an anionic or cationic form of the drug is to be delivered. Weak acid or weak base forms constitute a preferred class of such drugs. For example, oxidation of water proceeds according to the half reaction, H 2 O→2H + +1/20 2 +2e. Thus if the basic form of the drug (DOH) is incorporated into the reservoir, the reaction H + +DOH→H 2 O+D + would occur, preferably in the drug reservoir. By this choice of drug form or drug precursor, hydronium ion is removed by conversion to the neutral species, water, and the concentration of D + is increased. In addition, if a drug in its uncharged free-base form, D, were incorporated into the drug reservoir, then the use of an "inert" electrode to produce hydronium ion, via oxidation of water, would lead to the formation of the charged drug species DH + by the reaction D+H + →DH + . By this method, hydronium ion is removed by protonation of the drug and the concentration of the desired species DH + is increased. A particularly useful class of drugs which would behave in the fashion described above are tertiary amines (R 3 N). Specific examples of such drugs are propranolol, nadolol, and metoprolol. Conversely, the reduction of water occurs according to the half reaction, H 2 O+e - →OH - +1/2H 2 . If it is desired to deliver an anionic drug (D - ), the acid form of the drug (DH) should be incorporated into the reservoir. The reaction OH - +HD→H 2 O+D - would occur, thereby removing hydroxyl ions and increasing D - concentration. This application of the present invention suggests that if either a desired acid or basic form of a specific ionically delivered drug is not available, synthesis for purposes of enhanced iontophoretic drug delivery could be accomplished.
Two observations should be made regarding the description of the present invention in the previous paragraph. First, as described, an inert electrode is intentionally employed to oxidize or reduce water. The electrochemically active component of the drug delivery device (e.g., a stainless steel or platinum electrode component) in the iontophoretic drug delivery process without itself being electrochemically changed or consumed. Second, even though undesirable hydroxyl and hydronium ions are formed, deletrious pH changes are minimized and hydronium ions and hydroxyl ions are converted to neutral water. In this practice of the invention, the production of gaseous species i.e., H 2 and O 2 , occurs and thus the sacrificial methods earlier described should be chosen if gas evolution is to be avoided.
Reference is now made to FIG. 1 included herewith. In the figure, there is depicted, schematically, in cross section, a single substantially, circular electrode 10 which is intended for use in an iontophoretic drug delivery device. It is to be understood that electrode 10 is but one of the two electrodes necessary to successful operation of an iontophoresis device and that the necessary source of electrical energy is also not depicted herein.
Again referring to FIG. 1, electrode 10 comprises a support or housing 12 which is generally "U" shaped and which is preferably flexible. In a preferred embodiment, support 12 is produced from self-supporting polymeric foam. In this practice of the invention, perimeter surface 14 of housing 12 would optionally have disposed thereon a skin-compatible, pressure-sensitive, biomedical adhesive 16 which is intended to hold the electrode in place on the patient's skin during iontophoretic drug delivery. The iontophoresis device may be held in place by other means, e.g., a strap, in which instance adhesive 16 would not be needed. Thus it is to be understood, as depicted, electrode 10 contemplates delivery of drug generally toward the bottom of the page.
With further reference to FIG. 1, there is shown a drug reservoir 18 which, in this practice of the invention, is a gel or gel matrix 21 containing the ionic drug species 19 which is to be transdermally introduced across the skin barrier. In a preferred practice of the invention, the self-supporting, skin-compatible gel matrix 21 for the drug would contain sufficient drug 19 so that approximately a one molar solution (applying the definition of a molarity from solvent-solute interactions) would result. Drug concentrations (in the reservoir) in the range of 0.02M to 1.0M or more can be employed in the practice of this invention. In a preferred practice, the lower reservoir drug concentration ranges (e.g., less than about 0.5 molar) can be used in the efficient devices described herein. It should be noted that any of a number of possible gel matrices may be employed, those being described in the previously mentioned Webster patent comprising a particularly preferred practice of this invention. Agar or polyvinylpyrolidone gels also are advantageously employed herein.
Also in FIG. 1, there is depicted an exterior connector 20 which in this embodiment is a wire. Exterior connector 20 is in further electrical contact with a current distribution member comprising a tab or plate 23 in electrical contact with an optional screen 22. In this embodiment, the current distribution member would comprise silver. (The current distribution member need not be pure silver. An exterior layer of silver is all that is needed.) The silver screen is optionally included only to increase the surface area of the current distribution member.
Thus, in operation, an external source of electrical energy (not shown) would be connected to exterior connector 20 which is, in turn, electrically connected to the silver current distribution member 22, 23.
It should be noted and with reference to the cathodic description of the sacrificial electrode described above that the silver current distribution member shown could be a silver/silver chloride cathode. Electrode 10, as depicted, would be placed in contact with a patient's skin and pressed with sufficient firmness so that pressure sensitive adhesive 16 would hold the drug reservoir 18 in contact therewith by means of flexible housing 12. Silver tab 20 would be electrically connected to a source of electrical energy, preferably a small battery. Utilization of a battery permits iontophoretic drug delivery without substantial interference with the normal activities of the patient.
It is within the contemplation of the present invention that stationary electrical supply sources be employed in which case it would likely be necessary for the patient to be substantially immobilized. Although not depicted, a second indifferent or cooperating electrode would then be placed in contact with the patient's skin at a site separate from but electrically adjacent to the site on which electrode 10 has been placed. Upon connection to a source of electrical energy, migration of charged species from reservoir 18 would occur. In this embodiment of the invention, assuming the reservoir contains therein propranolol hydrochloride or lithium chloride, the silver tab 23 and silver screen 22 anode would be electrochemically consumed to produce silver ions as above described. These silver ions would react immediately with chloride ions which are also present to produce a neutral, substantially insoluble species. In this manner, enhanced delivery of propranolol or lithium would occur due to the fact that little hydrolysis occurs. The silver chloride precipitation reaction removes silver and chloride ions from the reservoir, thus further enhancing efficiency.
Heretofore, the discussion has focused upon the use of iontophoresis to treat humans. Obviously, the invention herein disclosed could be used with animals and should not be limited to humans.
The instant invention will now be illustrated by the following examples which should not be employed so as to limit the scope of this invention:
EXAMPLE I
Description of the Experimental Procedure
In-vivo studies of iontophoretic drug delivery were run on New Zealand white rabbits. As indicated, the rabbits were in some studies sedated as with pentobarbital, and others were merely constrained. The sedation studies generally were conducted for a time period not exceeding 7 hours whereas the "constrained" studies were run for time periods up to 30 hours. Each rabbit was used in a particular study only once.
As is more completely described below, an iontophoretic device employing an electrode as shown and described in FIG. 1 was used to introduce lithium, salicylate, propranolol or sodium chloride into the rabbits. The gel "reservoir" contained approximately a 1 molar concentration of each of the respective drugs. The device employed a silver anode and a silver/silver chloride cathode as described above.
The iontophoretic device was placed posteriorly on the rabbit, the hair having been clipped and removed with a dipilatory. The device was then attached by means of an adhesive for the duration of the experiment. During the experimental procedure, blood samples were removed from the subject rabbits. Where rabbits were anesthetized, blood samples were removed from their inferior vena cava by means of a catheter inserted into the femoral vein. For the experiments employing constrained (rather than anesthetized) rabbits, blood samples were pulled from the heart by means of a catheter inserted into the marginal vein of the rabbit's ear. The samples thus withdrawn then were analyzed for the drug which was iontophoretically introduced therein.
EXAMPLE II
Description of the Data Treatment
Employing the experimental procedure described in Example I, the drugs of interest were iontophoretically introduced into rabbits. Blood samples were withdrawn as described and analyzed, the concentration of the respective drugs being plotted as a function of time. The data so obtained then was fit to the expression
C=B .sup.(1-exp(-K i.sup.t))
where "C" is the concentration of drug in the rabbit's blood at a particular time; "B" is the steady state drug concentration, i.e. the highest concentration achieved when drug input and drug elimination are in equilibrium; K i is the iontophoretic decay constant; and "t" is time. Tables 1, 2 and 3 indicate values of these parameters for a number of runs (each "run" corresponding to numbers obtained from a given rabbit, indicated by letter, on a given day, indicated by number). The drugs delivered in Tables 1, 2 and 3 were lithium ion, salicylate ion and propranolol ion, respectively.
TABLE 1__________________________________________________________________________Lithium Drug Delivery Parameters Best Fit Parameters EfficiencyRun Current B K.sub.i C.sub.o K.sub.e V.sub.d E.sub.r E.sub.cNo. (mA) (mg/L) (hr.sup.-1) (mg/L) (hr.sup.-1) (liters) (%) (%)__________________________________________________________________________323A 10 3.0 0.66 0.16(a) 1.47(b) 27 24323B 0 0.94 0.26 0.16(a) 1.47(b)402C 20 5.2 0.31 0.16(a) 1.32(b) 21 20403A 5 6.0 0.77 0.16(a) 1.37(b) 102 79403B 10 4.4 0.84 0.16(a) 1.52(b) 41 36403C 20 8.7 0.60 0.16(a) 1.62(b) 44 41409A 30 16.7 0.31 0.16(a) 1.53(b) 53 51409B 20 7.0 0.79 0.16(a) 1.56(b) 34 32409C 10 6.6 0.29 0.16(a) 1.59(b) 65 57425A 0 -- -- -- 0.12425C 0 -- -- 1.41 0.09510A 1 0.3 -- 0.16(a) 1.63(b) 30510B 5 1.0 0.51 0.16(a) 1.89(b) 23510C 5 4.0 0.16 0.16(a) 1.82(b) 90 70611A 0 3.0 0.82 2.61 0.14 1.25 .sup.611B 0.5 0.27 0.19 1.97 0.19 1.66 .sup. 66 17611C 2 1.6 0.27 2.17 0.16 1.51 .sup. 75 44619F 0.5 3.0 1.72 0.16(a) 1.20(b) 445 116619G 0.5 2.9 1.06 2.62 0.27 1.25 .sup. 766 200619H 0 2.1 1.13 0.16(a) 1.40(b)619I.sup.1 0.71 0.20 0.16(a) 1.35(b) 59 24Average 0.54 0.16 43(c)S.D. ±0.32 +0.06 ±20__________________________________________________________________________ (a)assumed value based on average K.sub.e. (b)assumed value based on 0.49 × body weight in kg. (c)average for currents greater than or equal to 1 mA.
TABLE 2__________________________________________________________________________Salicylate Drug Delivery Parameters Best Fit Parameters EfficiencyRun Current B K.sub.i C.sub.o K.sub.e V.sub.d E.sub.r E.sub.cNo. (mA) (mg/L) (hr.sup.-1) (mg/L) (hr.sup.-1) (liters) (%) (%)__________________________________________________________________________323A 10 157 0.36 0.25(a) 0.72(b) 55 47323B 0 60.4 0.53 0.25(a) 0.72(b)402C 20 130 2.35 0.25(a) 0.65(b) 21 19403A 5 182 0.91 0.25(a) 0.68(b) 121 90403B 10 96.8 1.23 0.25(a) 0.75(b) 35 30403C 20 173 1.47 0.25(a) 0.80(b) 34 31409A 30 204 0.93 0.25(a) 0.76(b) 25 24409B 20 109 3.43 0.25(a) 0.77(b) 21 19409C 10 85.6 0.98 0.25(a) 0.78(b) 33 28425A 0 0.46425C 0 320 0.18 0.63510A 1 4 0.25(a) 0.80(b) 16510B 5 17.1 0.86 0.25(a) 0.93(b) 16510C 5 37.6 0.36 0.25(a) 0.90(b) 33 25611A 0 45.0 0.16 275 0.31 0.62611B 0.5 32.3 0.09 207 0.23 0.83 241 55611C 2 73.6 0.32 187 0.22 0.92 146 79619F 0.5 40 0.25(a) 0.59(a) 231 52619G 0.5 46.0 1.05 0.30 0.54 291 66619H 0 12 0.25(a) 0.68(b)619I.sup.1 37.9 0.94 0.25(a) 0.66(b) 122 45Average 0.73 0.25 28(c)S.D. ±0.42 ±0.06 ±9__________________________________________________________________________ (a)assumed value based on average (b)assumed value based on 0.24 × body weight in kg. (c)average for currents ≧5 mA
TABLE 3__________________________________________________________________________Propranolol Drug Delivery Parameters Best Fit Parameters EfficiencyRun Current B K.sub.i C.sub.o K.sub.e V.sub.d E.sub.r E.sub.cNo. (mA) (mg/L) (hr.sup.-1) (mg/L) (hr.sup.-1) (liters) (%) (%)__________________________________________________________________________613D 0.5 0.13 0.30 0.08 0.40 21.2 23 16613E 2 0.11 0.24 0.08 0.40 22.3 5 3627J 0 0 0.17 0.44 10.7 -- --627K 0.5 0.08 0.16 0.33 0.40 5.3 3 0627L 1 0.24 0.43 0.15 0.30 11.7 9 6705N 0.5 0.05 0.35 0.19 0.61 9.2 6 0705O 0.5 0.23 0.30 -- 0.39(a) 11.4(b) 21 14705P 1.0 0.17 0.26 0.08 0.47 22.3 18 15705Q 1.0 0.15 0.28 -- 0.39(a) 9.8(b) 6 3724R 0 0.35 0.14 0.24 0.39 7.2 -- --724S 0.5 0.13 0.30 -- 0.39(a) 15.1(b) 16 9724T 0 0.19 0.25 0.21 0.46 8.5 -- --724U 1.0 0.25 0.32 0.17 0.22 10.6 6 3801V 0.5 0.11 0.56 0.08 0.24 21.7 12 5801W 1.0 0.24 0.18 -- 0.39(a) 10.2(b) 10 7810X 0 0.05 0.63 -- 0.39(a) 10.9(b) -- --801Y 0 0.06 0.50 0.16 0.33 10.9 -- --Average 0.32 0.39 6.8S.D. ±0.14 ±0.11 ±5.6__________________________________________________________________________ (a)value based on average K.sub.e (b)value based on 5.3 × body weight in kg.
EXAMPLE III
For some of the rabbits tested, a known amount of a given drug was administered intravenously and the consumption of the drug by the animal was monitored as a function of time. From these data, values for the drug elimination decay constant (K e ) and the initial drug concentration (C o ) were determined by plotting the natural logarithm of concentration (1nC) versus time. Once the value of C o and the intravenous dosage has been determined, the volume of distribution (V d ) was calculated using the expression
V.sub.d =Dose/Co
Tables 1, 2 and 3 list the values of C o , K e and V d as they were determined or estimated for each run.
EXAMPLE IV
The parameters listed in Tables 1, 2 and 3 can be used to estimate the efficiency of drug delivery. An estimate of the steady-state drug delivery rate (R d ) can be made by multiplying the plateau drug concentration (B) by the volume of distribution (V d ) and the drug elimination decay constant (K e ), that is,
R.sub.d (mg/hr)=B V.sub.d K.sub.e (1)
The maximum amount of drug iontophoretically delivered per unit time (R t ) can be calculated from the current used during the experiment, that is, ##EQU1## where M is the molecular weight of the drug ion, I is the current in milliamps and F is Faraday's constant. The efficiency of drug delivery (E r ) can be estimated from the ratio R d /R t according to the expression ##EQU2## Tables 1, 2 and 3 list the efficiencies estimated from the in-vivo rabbit data for each experiment.
It is to be noted that for some of the runs, the value of E r exceeded 100%. This is possible since R d includes a contribution due to passive diffusion of the drug through the skin, therefore the ratio R d /R t can exceed unity.
EXAMPLE V
Also listed in Tables 1, 2 and 3 is the true efficiency of drug delivery (E c ) for each experiment which was calculated by subtracting the passive drug delivery rate (R p ) from the total drug delivery rate (R d ), that is, ##EQU3## The method used to determine the passive diffusion rate for each drug is discussed in Example VI below.
EXAMPLE VI
It was found that total in-vivo drug delivery data, as defined in equation (1) of Example IV, was the sum of two contributions, one passive and the other iontophoretic. Thus, it was found that the rate of drug delivery (R d ) could be expressed as
R.sub.d =R.sub.p +R.sub.i (4)
where R p is the rate of passive drug delivery and R i is the rate of iontophoretic drug delivery. The rate of passive delivery depends on the area of contact and the drug concentration of the drug reservoir. The rate of iontophoretic delivery is directly proportional to the current used in the experiment, that is,
R.sub.i =AE.sub.c I
where E c is the efficiency of drug delivery, I is the current and A is a proportionally constant whose value is determined by the molecular weight of the drug.
Substitution of the above expression for R i into Equation (4) yields
R.sub.d =R.sub.p +AE.sub.c I (5)
By using the data presented in Tables 1, 2 and 3, a plot of R d versus current can be made for each drug. From the form of Equation (5), it is readily seen that the intercept of a linear least-squares fit of such plots will yield the passive drug diffusion rate (R p ) and the slope can be used to calculate the efficiency of drug delivery (E c ).
EXAMPLE VII
From the data obtained as described above, a plot of R d versus current for lithium chloride, sodium salicylate and propranolol hydrochloride was made and a best linear fit obtained. The rates of passive drug delivery for each of these drugs then is determined by the intercept of this "fit". Values of this intercept are listed in Table 4. Also listed in Table 4 is the equivalent current for each drug. The equivalent current for a given drug is the current at which half of the drug delivery would occur via passive diffusion and half would occur iontophoretically.
The slopes of the best linear fit of R d versus current described above were used to estimate the efficiency (E c ) for in-vivo drug delivery. Table 5 compares the efficiency estimated from the in-vivo experiments to those determined from in-vitro drug delivery through excised rabbit skin and through polyvinyl alcohol (PVA) membrane into a 0.1M sodium chloride solution. The in-vitro drug delivery measurements were taken in accordance with using a Franz diffusion cell commercially available from the Crown Glass Company, Somerville, N.J., U.S.A.
The efficiency of in-vitro drug delivery through a PVA membrane is an indication of the relative mobilities of lithium and propranolol with respect to chloride ion, and salicylate with respect to sodium ion. The efficiency of drug transport through a PVA probably represents an upper limit for the efficiency for the gels, electrodes and drug concentrations likely to be used in the in-vivo experiments.
The data presented in Table 4 indicates that lithium and propranolol were transported approximately equally efficiently through excised and viable rabbit skin. Further the data indicates the salicylate was more effectively delivered through viable tissue than through excised skin.
TABLE 4______________________________________Passive Diffusion Rate EquivalentDrug R.sub.p (mg/hr) Current (mA)______________________________________Lithium 0.37 1.42Salicylate 8.8 1.71Propranolol 0.33 0.034______________________________________
TABLE 5______________________________________In-Vivo and In-Vitro Coulombic Efficiencies In-VitroDrug In-Vivo Rabbit Skin PVA Gel*______________________________________Lithium 35% 33% 30%Salicylate 19% 6% 30%Propranolol 5% 5% 11%______________________________________ *polyvinyl alcohol
To summarize, while there does appear to be a fair amount of scatter in the in-vivo data, we have found that the methods described herein provide a fairly reproducible method for determining efficiencies and passive drug delivery rates for in-vivo studies. The efficiencies so calculated appear to be in substantial agreement with similar efficiencies computed from in-vitro experiments.
EXAMPLE VIII
A number of anode/cathode drug combinations and drug concentrations were evaluated with respect to their minimization of the production of undesired species. In particular, drug reservoir pH changes were measured, from which hydronium ion delivery rates were computed. The drug passed through a PVA membrane and was delivered into a 0.06M Na C1. Further, using the mathematical treatment described above, drug delivery efficiencies were determined. Experimental conditions and efficiencies were measured for delivery of lithium ion, potassium ion and salicylate ion as indicated in Tables 6, 7, 8 and 9.
A number of observations may be made about the systems tested. Systems numbered 1-6 of Table 6 are basically prior art systems.
Undesirable water hydrolysis products are produced and thus pH is shown to change fairly substantially as in "pH" column for systems 1, 2 and 3 in Table 7, 1 and 2 of Table 8 and 1 of Table 9.
An evidenced in Tables 7, 8 and 9 hydronium delivery rates were generally higher, and drug delivery efficiencies were generally lower for prior art systems versus systems employing the present invention. For example, systems numbered 1, 2 and 3 in Table 7 may be compared with systems numbered 4-9 in Table 7. Similarly systems 1 and 2 in Table 8 should be compared with 3-6 in Table 8 and system 1 in Table 9 with 2-8 in Table 9.
To summarize, in conjunction with the teaching above, a broadly-based, flexible approach to solving the problem of inefficiency/instability in iontophoretic drug delivery is disclosed. While this disclosure has focused upon two cationic and one anionic drug, it will be appreciated that this invention is broadly applicable to the iontophoresis art. The attached claims should be so broadly construed.
TABLE 6__________________________________________________________________________Summary of Experimental Conditions Reservoir Concen- tration ElectrodeDrug (M) Material Electrode Reaction Neutralization Reaction__________________________________________________________________________ 1. LiCl 0.06 Platinum H.sub.2 O → 2H.sup.+ + 1/2O.sub.2 None.sup.- 2. LiNO.sub.3 0.06 Platinum " " 3. LiCl 0.06 S. Steel " " 4. KCl 0.06 Platinum " " 5. K.sub.3 Fe(CN).sub.6 0.02 Platinum " " 6. NaSal 0.06 Platinum H.sub.2 O + e.sup.- → OH.sup.- + 1/2 "sub.2 7. LiNO.sub.3 0.06 Silver Ag → Ag.sup.+ + e.sup.- None 8. LiNO.sub.3 0.06 Copper Cu → Cu.sup.++ + e.sup.- " 9. KNO.sub.3 0.06 Silver Ag → Ag.sup.+ + e.sup.- "10. NaSal 0.06 Ag/AgCl AgCl + e.sup.- → Ag + Cl.sup.- " HSal Solid Ag/AgCl AgCl + e.sup.- → Ag + Cl.sup.- " Cu(Sal).sub.2 0.05 Silver Cu.sup.++ + 2e.sup.- → Cu " AgSal 0.04 Silver Ag.sup.+ + e.sup.- → Ag " AgSal Solid Platinum Ag.sup.+ + e.sup.- → Ag " LiCl 0.06 Silver Ag → Ag.sup.+ + e.sup.- Ag.sup.+ + Cl.sup.- → AgCl Li.sub.2 CO.sub.3 0.03 Silver Ag → Ag.sup.+ + e.sup.- 2Ag.sup.+ + CO.sub.3 → Ag.sub.2 CO.sub.3 LiCl 0.06 Copper Cu → Cu.sup.+ + e.sup.- Cu.sup.+ + Cl.sup.- → CuCl LiOH 0.06 Platinum H.sub.2 O → 2H.sup.+ + 1/2O.sub.2 H.sup.+ + OH.sup.- → H.sub.2 O KCl 0.06 Silver Ag → Ag.sup.+ + e.sup.- Ag.sup.+ + Cl.sup.- → AgCl20. K.sub.3 Fe(CN).sub.6 0.02 Silver Ag → Ag.sup.+ + e.sup.- 3Ag.sup.+ + Fe(CN).sub.6.sup.3- → Ag.sub.3 Fe(CN).sub.6 K.sub.3 Fe(CN).sub.6 0.02 Copper Cu → Cu.sup.+ + e.sup.- 3Cu.sup.+ + Fe(CN).sub.6.sup.3- → Cu.sub.3 Fe(CN).sub.6 AgSal Solid Ag/AgCl AgCl + e.sup.- → Ag + Cl.sup.- Cl.sup.- + AgSal → AgCl + Sal.sup.- HSal Solid Platinum H.sub.2 O + e.sup.- → OH.sup.- + 1/2H.sub.2 OH.sup.- + HSal → H.sub.2 O + Sal.sup.-__________________________________________________________________________
TABLE 7*______________________________________Comparison of Lithium Drug Delivery Systems Hydronium % Drug Delivery pH Anode Delivery Rate Initial AfterDrug Material Efficiency (moles/hr) Value 6 hrs______________________________________1. LiCl Platinum 20.2 3.2 × 10.sup.-6 5.9 2.62. LiNO.sub.3 Platinum 22.8 2.0 × 10.sup.-6 7.2 2.53. LiCl S. Steel 29.1 1.8 × 10.sup.-7 6.2 3.74. LiNO.sub.3 Silver 28.5 5.5 × 10.sup.-8 5.9 4.35. LiNO.sub.3 Copper 25.0 <10.sup.-9 5.9 5.66. LiCl Silver 36.7 <10.sup.-9 6.5 6.27. LiCl Copper 30.2 <10.sup.-9 6.1 5.58. Li.sub.2 CO.sub.3 Silver 29.5 <10.sup.-9 10.6 10.29. LiOH Platinum 41.6 1.5 × 10.sup.-8 11.5 11.3______________________________________ *All results obtained at a current of 1 mA.
TABLE 8__________________________________________________________________________Comparison of Potassium Drug Delivery Systems* % Drug Hydronium pH Anode Delivery Delivery Initial AfterDrug Material Efficiency Rate (moles/hr) Value 6 hrs__________________________________________________________________________1. KCl Platinum 33.7 1.4 × 10.sup.-6 5.8 2.72. K.sub.3 Fe(CN).sub.6 Platinum 28.6 2.1 × 10.sup.-6 6.4 2.63. KNO.sub.3 Silver 36.2 5.4 × 10.sup.-9 5.8 4.34. KCl Silver 39.1 <10.sup.-9 6.0 5.65. K.sub.3 Fe(CN).sub.6 Silver 34.3 1.0 × 10.sup.-8 6.4 5.96. K.sub.3 Fe(CN).sub.6 Copper 33.8 .sup. 8.9 × 10.sup.-10 7.2 4.9__________________________________________________________________________ *All results obtained at a current of 1 mA.
TABLE 9__________________________________________________________________________Comparison of Salicylate Drug Delivery Systems* pH % Drug Delivery Hydroxyl Delivery Initial AfterDrug Material Efficiency Rate (moles/hr) Value 6 hrs__________________________________________________________________________1. NaSal Platinum 25.9 4.6 × 10.sup.-6 6.0 11.52. NaSal Ag/AgCl 27.8 <10.sup.-9 6.5 5.63. HSal Ag/AgCl 20.9 <10.sup.-9 3.5 2.94. Cu(Sal).sub.2 Silver 28.3 <10.sup.-9 4.5 4.55. AgSal Silver 28.2 1.0 × 10.sup.-7 8.6 8.76. AgSal Platinum 24.9 3.3 × 10.sup.-8 5.2 8.17. AgSal Ag/AgCl 25.0 .sup. 2.9 × 10.sup.-10 5.2 5.48. HSal Platinum 28.1 .sup. 8.6 × 10.sup.-11 2.8 3.4__________________________________________________________________________ *All results obtained at a current of 1 mA. | Improved methods of ionophoretic drug delivery are described. By the intentional selection of drug(s) with specific characteristics, of ionotophoresis device, components or both permits the efficiency of drug delivery is increased. | 0 |
TECHNICAL FIELD OF THE INVENTION
The present invention is directed to a new and improved method of changing a gear ratio without the necessity of disengaging a torque from the system.
BACKGROUND OF THE INVENTION
For many years the changing of gear ratios in a mechanical device has been accomplished by disengaging the torque usually with a clutch.
Attempts have been made to force engagement with random selection, but this required a complete disengagement of the torque.
Different non-mechanical designs have been used for the purpose of changing the ratio with continuous torque. One is a double pulley arrangement that drives a V-belt, and constructed of metal elements. This is presently used in snowmobiles.
An other design uses rolling elements between an inner input and an outer output gear arranged much like an epicyclic gear train. The rolling elements can continuously change the gear ratio but they are torque-limited because they rely on the coefficient of static friction to transmit forces between the rolling elements.
DISCLOSURE OF THE INVENTION
Power can be applied to either end of the mechanism depending upon the application. In a bicycle application, power begins at the bike peddle and travels down the crank arm to the crank. The crank is affixed to a drive plate. Usually three or more ring gears on the drive plate are associated with and engaged to each of three or more cam gears. The drive plate by means of the ring gears transfers power to the cam gears. Three steel ball bearings (detents) are locked into the cam valley of the cam gear by means of a shifting bullet. This allows power to transfer from the cam gear through the detents to the drum. Power is then transferred from a drum through the drive gear to the outer sprocket. A chain then delivers power to a rear wheel.
Shifting
A shift occurs when the center of the bullet is moved along its axis from the center of one active cam gear to the center of the cam gear desired, and by means of tapered ends on its leading and trailing ends, it allows the active set of detents to drop from their cam valleys and release the active cam gear, while simultaneously wedging a new set of detents from their peaks to the locked position of their valleys. The shift is initiated when the valley of the active gear is in the same position of rotation along its axis as the peak of the gear is being shifted into. Therefore the position of the cam gears must be timed and consistently relative to each other in order to initiate predetermined and uninterrupted shifting.
If we were to divide the movement of the bullet along its axis into 10 equal positions which represent the shift of one gear, then in the 0 and 10 positions the active gear is locked into engagement and the adjacent higher and lower output gear detents would be free of engagement. In position 1 the active output gear is 10% of the way to being disengaged while the output gear being shifted into is 10% of the way to being engaged. In position 2 the active output gear is 20% of the way to being disengaged while the output gear being shifted into is 20% of the way to being engaged and so forth until position 10 when the active gear becomes inactive and the gear being shifted into becomes the new active gear. During the left sequence positions 1 through 9 there are two gears with different ratios in partial engagement at the same time. No matter how fast the two gears are rotating, the shift is accomplished by their relationship to each other and that is influenced by their difference in ratio. Close ratios can allow relatively long periods of time to complete the shift. In some circumstances the shift could take several revolutions of the output gear to complete. The drum rotation is determined by the detent and during shifting represents a compromise between the active gear rotation and the rotation of the gear being shifted into.
Timing
Shifting can only be initiated when a valley of one cam gear and the peak of the cam gear desired are in the shift start position of rotation. Therefore shifting must be timed, predeterminable, and consistent. The valley and the peak must line up for the purpose of initiating the shift at the same place every time. This is accomplished by making the circumferences of the cam gears and the circumferences of the ring gears and the number of the peaks inside the cam gears all relative to each other.
The marked point on the drive plate at which a cam valley is perpendicular is called "0". The shift initiating starts with reference to a input drive plate and can be engineered for various intervals.
Cam gears are of equal diameter and a number one cam gear is being rotated by a smallest number one ring gear. For every rotation of the drive plate the number one cam gear must rotate at least one time. If it rotates a fraction more than once, the fraction must be devisable of the number of cams in the gear. For example, if the cam gear has six valleys, the additional rotation must be at least one-sixth of a rotation or sixty degrees more than one revolution. This rule applies for each consecutive cam gear. The number two cam must travel at least one-sixth, one-third, one-half, two-thirds, five-sixths, one, and one and one-sixth etc., more than the number one cam. The different amounts of increase in rotation of the cam gears and the number of the cams all effect the intervals at which the shift can take place.
To increase the rotation of the number two cam gear in relation to the number 1 cam gear more circumference is added to the number two ring gear so that the number two cam gear will have to travel a distance equal to the number one cam gear plus the value equal to at least the devisable of the number of cams in the cam gear. When the two shifting intervals are desired in one rotation, the increase must be equal to the full divisible of two. With the one-third increase of the number two cam gear the peak of the number two cam gear and the valley of the number one cam will gear consistently and invariably line up at the 0 and 180 marks. Note: the number one gear valleys, the number two gear peaks, the number three gear valleys and so forth line up at the 0 and 180 marks. The detents line up to determine the start of the shift sequence. They line up differently when the apertures in the drum are offset.
The cam gears and the number one ring gear both have equal circumferences. If we add for example one-sixth more circumference to the number two ring gear, it will rotate one-sixth more. This will allow the shift interval to be initiated at the same reference point on the drive plate every time. An increase of the circumference is proportionally equal to an increase of the radius. Provided with these measurements, the peak and the valley of the adjoining cam gears would line up on rotation at predetermined points, thus, timed shifting can be initiated.
The invention includes a wide variety of variables, the number of the peaks and the valleys in the cam gear and the ratios desired can all be manipulated to accomplish the task for which it is intended.
A lever convenient to a rider is connected to one end of a push-pull cable. At the other end, the cable is connected to one end of the bullet positioning mechanism. The shift shaft is connected to the bullet, which engages the desired gear as it disengages from the active gear. A timing cam is located on the drive plate to time and activate the shift mechanism at the appropriate timed interval.
Basic In-Line Arrangement
The transmission consists of the two shafts. Each shaft has a group of gears which are centered on the shaft and arranged next to each other along the axis of the shaft. One of the shafts has the gears permanently attached to the shaft, either machined from the same bullet or bolted to the shaft. For the purpose of this discussion, this shaft will be referred to as the input shaft (though either can be input). The gears on the other shaft are capable of being locked to the shaft via an arrangement of cams and locks. This shaft will be referred to as the output shaft in this discussion.
The two shafts and their gears are sized and arranged such that when the two shafts are placed in their restraints (bearings), the gear on the input shaft engages the gear on the output shaft and the gear on the output shaft engages the gear on the input shaft.
Each pair of gears, that is, one gear on the input shaft and one gear on the output shaft has a different gear ratio than the adjacent pair of gears. In general, each pair of gears has a different gear ratio than every other pair of gears in that particular transmission. Also, the gear ratios increase in one direction along the shaft and decrease in the other direction.
Power Flow
As stated above all of the gear pairs are engaged. However, only one of the gears on the output shaft is locked to the output shaft via the cams and the locks for that gear set. Power transmits through the transmission via the one locked gear.
Power flow characteristics (speed and torque), through the transmission, can be changed by changing the gear that is locked to the output shaft.
Output Assembly Components
The output assembly is composed of the following pieces of hardware:
1. A plurality of cam gears each of which is shaped like flat donuts where an outer surface is the gear teeth profile and a hole consists of a continuous cam surface consisting of repeating segments cut into an inner diameter of the gear. Each segment of the cam surface is in general composed of three sections which form a V or U shaped valley into which the detent can be inserted. The peak created between the valleys is identified as one of the three sections. A side section of the valleys are steep enough that when the detent is inserted into the valleys and held there by the underlying bullet structure, which is connected to the shift shaft, the gear and the output shaft are locked together. One cam valley can be cut into each gear, preferably at least two, and more preferably three to six depending upon the application. The profile of the cam sections can be shaped to influence the characteristics of a shifting sequence. There are many variables that are available depending upon the application. For example, in the six cam design, where rotations differ by one third for every rotation of the input shaft, the cams can be divided into two sets. One set will line up on the zero mark and the other set will line up on the one eighty mark. The set can have surfaces with their own profiles to perform function for upshifting uphill and downhill and another set for downshifting uphill and downhill.
2. An output shaft includes a hollow cylinder (drum) whose outer diameter is sized to fit inside the inner diameter of the gears with a sliding oil tolerance fit. The guide apertures contain the detents (locking elements, generally two or more to correspond with the number of valleys in the cam surface) that are balls or dogs and the tops are shaped to engage the cam surface. The detents may include a variety of shapes; rounded, triangular, preferably the shape conforming to the cam valley and maximizing the surface to surface contact area. The detent is also designed in such a way as to direct as much as possible a vector force into the drums rotation and not radially into the bullet. The guide apertures are cut in the output shaft and a group of the guide apertures (generally two or more) are positioned such the guide apertures are directly underneath each gear that is fitted over the output shaft.
If desired the drum can be designed into the input shaft. The design provides a different input and output ratios and the rules of interaction between the principle components are the same in either application.
3. A plurality of detents each of which is a metal ball, a pin, a rectangular cube or the like with tops to correspond with the cams, and sides that slide in and out of the guide aperture cut in the output shaft and a bottom to correspond to the grove in the bullet. In some applications the cam and the detent arrangement is so configured as to minimize the forces acting upon the bullet and direct as much as possible the forces acting upon the wall of the aperture of the drum. Basically the steeper the angle of the detent top and corresponding the cam surface the more force is directed into the drum. The detent and cam tolerances along with a orifice in the detent, control oil movement for the purpose of lubricating and dampening the shift.
4. A bullet which is a cylindrical piece that fits inside the inner diameter of the output shaft which has contoured grooves cut in the outer surface to receive the bottom of the detent. The bottom of the groove in the bullet is the cam surface which can be designed to control (along with the shape of the cam surface on the inner diameter of the output gear) the characteristics of the shifting sequence. The bullet is connected to and maneuvered by a screw shaft. Generally the bullet is designed to move with the natural flow of the forces created by the movement of the cams in the active output gear to the inactive gear, but the movement of the bullet can so be delayed or advanced so as to manipulate the output gear and direct the movement of the detents to mesh through the transfer of the varying gear ratios. The bullet is not limited to the number of cams to equal the number of detents. The bullet can be rotated in its angular relationship inside the drum to utilize the set of cam surfaces for the upshift and rotate back for the set of cam surfaces for the downshift. The bullet cam surfaces can be in line as in (FIG. 5) or the bullet cam surfaces can follow a corkscrew configuration.
5. A bullet positioning mechanism to control and to change a position of the bullet generally by means of the screw shaft. This can be accomplished in a variety of ways such as a mechanical lever, a mechanical advantage with gears, an electrical motor, an electrical solenoid, a pneumatic mechanism, etc. All the positioning mechanisms must function with response to timing and magnitude. The bullet positioning mechanism can also be timed in conjunction with a torque sensing device.
Shifting Sequence
The following terms are defined to simplify the description of the shifting sequence:
The active gear pair means the pair of gears that are currently transmitting power;
The Up Shift means a change in the active gear pair such that the ratio of the input to the output is a numerically smaller number, for example, the shift from the gear ratio (input to output) of 5 to a gear ratio of 4; and,
The Down Shift means a change in the active gear pair such that the ratio of the input to the output is a numerically larger number, for example, the shift from the gear ratio (input to output) of 4 to a gear ratio of 5.
The shifting sequence is the result of the configuration of the cam surfaces and the arrangement of the components that constitute the output shaft and its associated mechanism to change the output gear that is locked to the output shaft.
The description of the shifting sequence will start with the transmission rotating and the active gear pair being a gear pair that is in the mid-range of the transmission. That is, the transmission is operating in the gear such that it can be either Up Shifted or Down Shifted. The power flow enters through the input shaft and is modified in speed and in torque by the gear ratio of the active gear pair.
The active gear pair is locked to the output shaft because the bullet has been positioned under the detent for that gear hence, forcing the gear up into one of the open spaces formed by the cam valleys that are cut into the inner surface of the gear. The detents are held in position up against the cam surface by the bullet. Therefore, the gear and the output shaft are locked together.
All of the other detent for the gear pairs, other than the active gear pair, are not being held in position against the cam surface of their respective gears by the underlying bullet and therefore any force acting between the detent and the cam surface has a radial component which will drive the detent inward radially and hence the non-active output gears are free to rotate relative to the output shaft.
The non-active gear pairs adjacent to the active gear pair have gear ratios that are different than that of the active gear pair. Therefore, the output gear on the output shaft that is adjacent to the active output gear is moving relative to the active output gear. The output gear is also moving relative to the output shaft inside of it, that is all of the output gears that are non-active are moving relative to the output shaft and the detents are retracted into the aperture of the drum of the output shaft. The magnitude to the relative motion depends on the difference in the gear ratio of the active and the non-active output gears. The relative motion causes the valleys of the cam surfaces in the output gears and the retracted detents in the output shaft to periodically coincide or line up. When the valleys of the cam surfaces and the detent for either of the output gears adjacent to the active gear pairs line up then the shift can occur. Or more accurately, as the cam valleys and the detent for either output gear adjacent to the active gear pair approach coincidence, the shift sequence can start. The engaged detent of the active output gear must be allowed to retract in order for the shift to take place. This is accomplished by the timed synchronous movement of the bullet.
Down Shifting
A down shift requires that the adjacent gear pair which has a higher numerical gear ratio be engaged substantially simultaneously while disengaging the active gear pair. Because the to-be-engaged gear pair has a larger numerical gear ratio, the gear on the output shaft is rotating at a lower rate than the output shaft inside of its inner diameter; and hence, the detent in the output shaft inside the output gear are rotating faster than the gear itself and will, after a certain angle of rotation, be moveable into the position required to be fully engaged. Therefore, when the detent in the output shaft which is matched for the gear to be shifted into is at the peak of the cam surface cut in the inner surface of the gear, the shifting sequence starts. The sequence is controlled by the bullet. At the start of the sequence, the bullet begins to move toward the gear pair to be engaged. This movement accomplishes the following: 1) The detent for the to-be-engaged gear pair starts to move out into the space created by the valley of the cam profile, and 2) the bullet moves out from under the active gear pair and allows the forces between the detent, the cam surface and the output gear to force the detent radially inward into the aperture in the output shaft.
During the disengagement of the active gear pair, that is, while the detent is withdrawing it is still in contact with the cam surface for the active gear pair, the side of the hole in the output shaft, and the bullet and is still transmitting torque. As this detent is being withdrawn, the detent for the to-be-engaged gear pair is being forced radially outward against the cam surface of the to-be-engaged gear. When the active gear pair detent is moved radially inward and off the cam surface and into the circular inner surface of the drum and is no longer locking its gear to the output shaft the to-be-engaged detent is in contact with the cam surface the hole in the output shaft and the bullet and locks its gear to the output shaft. The shift is now complete.
The different amounts of rotation of the input and output shafts that occurs during the shifting process is determined by the difference in the gear ratios of the two gear pair involved in the gear shift. The shifting sequence is controlled by the bullet. The bullet must be moved out from under the detents of the active gear pair to allow the driving force on the detent to drive it inward and, at the same time, the bullet must push the detents of the to-be-engaged gear pair outward into contact with the cam surface for that gear pair. The shape of the cam surface on the bullet, the cam surface on the gear and the shape of the detent all influence the characteristics of the shift and are selected to provide a smooth transition between adjacent gear ratios.
For a downshift, the output shaft will start to slow immediately when the shift sequence starts. This is because the detent starts to withdraw, and as it does so, it slides inwardly along the cam surface such that the corresponding gear around the output shaft rotates more than the output shaft. This different output rotation rate continues to change until the to-be-engaged detent reaches the fully inserted position where it locks its gear to the output shaft, at which point, the output shaft rotation rate will be that determined by the now-active gear pair gear ratio. For a Down Shift the final output shaft rotation rate will be lower than the rotation rate before the shift.
In the start position or the zero mark the resistance alone and with out the aid of rotation, could with the force at FS1 complete a shift by riding the cam surface SS3 if FS1 were larger than SS3. A longer smoother method is to make the FS1 smaller than SS3 and allow for a shift along SS1.
Up Shifting
An up shift requires that the adjacent gear pair which has a smaller numerical gear ratio be engaged simultaneously while disengaging the active gear pair. The up shift is similar to the down shift except that the gear on the other side of the active gear pair is the one to be engaged and the output gear for the to-be-engaged gear pair is rotating faster than the output shaft. Further, because the to-be-engaged gear pair is rotating faster than the output shaft the detent approach their respective cam surfaces from the opposite side as compared to a down shift. That is, the detent for the to-be-engaged gear pair will slide down the opposite side section of the V or U shaped cam surface. For an Up Shift, the output shaft will start to slow immediately when the shift sequence starts. This is because the detent starts to withdraw and as it does so, it slides inwardly along the cam surface such that the corresponding gear around the output shaft rotates more than the output shaft. This difference in output rotation rates continues to change until the to-be-engaged detent reaches the fully inserted position where it locks its gear to the output shaft at which point the output shaft rotation rate will be that determined by the now active gear pair gear ratio. For an Up Shift the final output shaft rotation rate will be higher than the rotation rate before the shift.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be further understood from consideration of the detailed description below taken in conjunction with the accompanying drawings in which:
FIG. 1 is a diagrammatic side elevation view of a men's bicycle provided with a gear shifting mechanism according to the invention.
FIG. 2 is a diagrammatic side elevation and cross sectional view of the gear shifting mechanism according to the invention.
FIG. 3 is a cross sectional view of a six valley cam gear.
FIG. 4 is a cross sectional view a the three valley cam gear.
FIG. 5 is a end view of the bullet.
FIG. 6 is a side view of the bullet.
FIG. 7 is a cross sectional view of the shift control mechanism.
FIG. 8 is a cross sectional perspective view of the shift control mechanism.
FIGS. 9A to 9F represent a pictorial example of the relationship between the cam gears cam surfaces, the detents and the drum in an downshift cycle.
FIGS. 10A TO 10F represent a pictorial example of the relationship between the cam gears cam surfaces, the detents and the drum is an upshift cycle.
FIG. 11 is a cross sectional view of the in-line transmission.
FIG. 12 is a cross sectional view of the shift shaft drive gears and there relationship to the end view of FIG. 11.
FIG. 13 is a cross sectional view of the shifting mechanism and the downshift cam and there relationship to the shift shaft actuating collar.
FIG. 14 is cross-sectional view of the outside edge of the plate and the outer drive sprocket.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a diagrammatic side elevation view of a men's bicycle with handle bars 20 on top of a down tube 22 and a seat 24 on top of a seat tube 26. At the crank housing 28 between the down tube and the seat tube, and mounted to the seat tube and down tube, is a gear change mechanism housing 30 according to the invention. Attached to the handle bars is a push pull type shift lever 32. Attached to the lever, and running along and down the down tube to the gear change mechanism is a push pull cable 34 with in a sheath 35. The sheath is supported by a support 36.
A peddle 37 is attached to the radially outward end of a crank arm 38. The crank arm is affixed to and rotates a crank shaft 40. The crank shaft drives the gear change mechanism.
The gear change mechanism drives a chain sprocket 42, which drives the chain 44, which rotates the rear sprocket 46, which turns the rear wheel 48.
FIG. 2 shows a diagrammatic side elevation and cross sectional view of the gear changing mechanism. The crank shaft 40 is affixed to the drive plate 50. A series of eight ring gears 52 with varying circumferences are affixed to the drive plate. The eight ring gears contact and engage each of eight cam gears 54 by means of uniform gear teeth on the ring gears and identical matching teeth 56 on the outer circumference of the cam gears. The cam gears are typical spur gears with six uniform cams 58 (FIG. 3) on their inner circumferences. The cams are comprised of three separate surfaces; a peak 60, a surface 62, and a valley 64. The peaks define the inner circumference of the cam gear, and it is upon these peaks and the sides of the gears that the cam gears rotate around the outer circumference of a drum 66. The drum is mounted at both ends for rotation, by bearings 68. The bearings also retain the cam gears in their lateral position along their axis. The drum is hollow with three apertures 70 corresponding to each of the eight cam gears. The apertures extend from the inner drum surface to the outer drum surface. Each of twenty four drum apertures correspond to a detent 72. The inward bottom surface of the detents come in contact with a bullet. The bullet is mounted within the drum such that it has reciprocal axial movement back and forth along the drum axis. The bullet contains six outer cam surfaces 74 (FIG. 5), each having a central portion extending radially upon which the detents ride. The axial movement of the bullet is regulated by a screw shaft 76. Keyed to the narrow extension of the drum is a drive gear 78. The drive gear is a spur gear with the same outer tooth profile as the cam gears. The drive gear continuously engages a ring gear 80 similar to the ring gears 52. The ring gear 80 is affixed to an outer drive sprocket. The outer drive sprocket rotates independently of the drive plate and it fits over the outside circumference of the drive plate on both sides forming a "U" shape. The bottom of the "U" hold small ball bearings 82 which ride the outer edge of the plate. The legs of the "U" shape extend inward, past the outside circumference of the drive plate.
The push pull cable 34 is connected to a female configured cable end 84. The cable end is attached to a shift actuator shaft 86 at a male ball end 87. The shift actuator shaft is supported so as to provide axial rotation and reciprocal axial movement along its axis by bushings 88 which are attached to the housing. As the shift actuator shaft is pushed or pulled along its axis it engages a shift actuator gear 90 by means of fixed keys 92 on opposite sides of its circumference. The shift actuator gear has a keyway to receive the keys of the shift actuator shaft. The shift actuator shaft includes an actuator pinion 94. When the shift actuator shaft is moved on its axis the pinion moves an upshift rack 96 and a down shift rack 98 referred to as shift racks. The shift racks are contained by a rack housing 100. The rack housing allows reciprocal lateral movement of the shift racks from the plate and by means of a keyway 102 (FIG. 8) on its sides allows the shift racks to move laterally along the shift actuator shaft axis. In the pushed position of the cable the downshift rack and its roller moves over and in line with the downshift cam 200 which is affixed to the surface of the drive plate. In the pull position of the cable the upshift rack and roller move over and in line with the upshift cam 104 which runs parallel to the downshift cam around the drive plate. The shift racks are returned to their neutral position by a rack spring 106. The shift actuator gear has teeth on its outer circumference that engage the teeth of a shift collar 111. The center hole of the shift collar is threaded to receive the screw shaft 76. The screw shaft is held from rotating along its axis by a screw shaft washer guide 108. The screw shaft washer guide is bolted to the housing and has a key built into its inner circumference that slides in a slot 110 in the screw shaft. (shown as hidden lines in FIG. 2)
The peddle transfers torque through the crank arm to the crank, which rotates the drive plate. The ring gears rotate all the cam gears but only the cam gear which is directly over the bullet has engaged detents and transfers torque. The locked detents transfer torque from the cam surface of the cam gear to the drum at the aperture wall. The drum then rotates the drive gear, which rotates the outer sprocket, which drives the chain, which rotates the rear sprocket, which rotates the rear wheel.
A downshift is initiated by pushing the lever on the handle bars, this pushes the cable inward toward the crank, which pushes the shift actuator shaft inward simultaneously engaging the shift actuator gear and moving the rack housing inward and the downshift rack over the downshift cam. The down shift cam can temporarily delay the inward movement of the downshift rack if it is not at its low point. The downshift cam pushes the downshift rack away from the plate causing its gears to engage the gears of the pinion. FIG. 8 shows the upshift rack, the downshift racks teeth are on the opposite side and cause the pinion to rotate counter clockwise. The shift actuator shaft rotates in the same direction as its pinion and causes the screw shaft collar to rotate in such a ways as to force the screw shaft inward. This causes the bullet to begin traveling inward. As the bullet begins to move inward it releases the detents from its valley and along its cam surface while simultaneously lifting the detents of the adjacent lower gear. An upshift is initiated by pulling the lever which pulls the cable, which pulls the shift actuator shaft, which locks the shift actuator gear and lines up the upshift rack over the upshift cam. The cam lifts the upshift rack away from the plate and causes it to engage the pinion. The pinion rotates clockwise which rotates the shift actuator gear clockwise, which rotates the screw shaft collar in such a way as to cause the screw to move outward and engage the adjacent higher gear. The placement and duration of the upshift and downshift cam is predetermined for the purposes of timing.
FIG. 4 shows the cross sectional view of a cam gear with three cams verses six cams in FIG. 3.
FIG. 5 shows the end view of the bullet. Contour lines show the varying amounts of line contact between the detent and the bullet.
FIG. 6 shows the side view of the bullet. For clarity only the top and bottom cams are shown by hidden lines.
FIG. 7 & 8 are sectional views and are explained in connection with FIG. 2.
FIG. 9 & 10 pictorially represents the actual relationship of the cams, detents, and drums in there respective rotations and movements. Different detents and cam surfaces from FIGS. 2 and 11 are included as examples of varying applications, though the angles and relative movements apply. FIG. 9 is the low to high ration 6 or downshifting cycle.
The object of a shift is to release a set of detents from the cam valleys of one output gear, while simultaneously engaging a set into the cam valleys of an adjacent output gear. This exchange of engaged output gears effects the varying rotational outputs.
Initially, in a downshift, the drum portion of the output shaft is locked to and rotating with the faster rotating output gear, due to the engaged detents. The disengaged detents inside the to-be-engaged slower rotating output gear are rotating faster than the slower gear. The force "F" and the resistance "R" push the "HD" (HIGH SPEED OUTPUT GEAR DETENT) radially inward sliding it along (HIGH SPEED OUTPUT GEAR CAM SURFACE #1) "HS1" releasing it from the faster rotating gear. Simultaneously, the "LD" (LOW SPEED OUTPUT GEAR CAM SURFACE #1), by means of the bullet, is forced radially outward and slides down "LS1" until it reaches the valley "V". The "HD" will slide in just as fast as "LS1" will let the "LD" slide out. This movement is synchronized by the travel speed and cam surfaces of the bullet. As "LS1" and the bullet allow the "LD" to move out, the bullet is allowed to move along its axis, which allows the "HD" to move in, which slows down the drum rotation, which all simultaneously slows down how fast the "LD" moves out. All of this simultaneous movement effects the output drum rotation and the number of degrees the input must rotate to complete a shift. (All the gear rotations are fixed and are referenced to the input shaft rotation.) The forces "F" and resistance "R" relationship at "HS1" and its peak "P" move the "HD" all the way in and along with the simultaneous movement of the bullet, move the "LD" all the way out, to complete a shift. The shift is complete when the "HS1" peak (P) is in the same position of rotation as the "LS1" valley (V).
The ability to predetermine the lining up of peaks and valleys for the purpose of initiating a shift is a product of, and timed with reference to, the angular rotation of the input shaft or drive plate. If the slower speed output gear (cam gear) travels X degrees of the input shaft, then, the higher speed output gear travels X+YX degrees of the input shaft. Y is a variable parameter determined by the ratio between gear pairs. If gears travel at the same velocity there isn't a potential for creating a shift. It is the difference between gear ratios and the angular measurement of the cam surfaces arc that determine the shift interval. (X+YX)-X represents the difference between output gears. When the downshift involves HS1 and LS1 the difference in rotation must allow for the full angular arc of HS1 and LS1. Hence (X+YX)-X=HS1+LS1.
Low to high shift or upshift. FIG. 10. Initially, the drum portion of the output shaft is rotating with the low gear by means of the engaged "LD". The drum portion of the output shaft and the disengaged "HD" rotates slower than the high gear. The force "F" and the resistance "R" push the "LD" inward sliding it along "LS1" and releasing it from the low gear. In the upshift cycle the resistance performs most of the movement required for the shift. The active cam surfaces HS2 and LS1 of the gears fall in the path of this negative drum rotation. If detent HD were not considered, the force and resistance alone at the slower gear would move the drum equal to the arc angle of LS1. If HS2 equals LS1 no rotational difference would be required between SG and FG. But if LS1 and HS2 were equal the shift would have to finish the instant it started, So it is important for HS2 to be larger than LS1 to allow time to shift. There are many manipulations that can be done to change this out come, one of which is modification of the bullet. So as indicated the resistance at LS1 is responsible for moving the bullet the arc angle equal to LS1. The difference between HS2 and LS1 must be provided by the difference between SG and FG.
In the upshift the detents travel negative with respect to their respective gears. The differences of all cam surfaces must be such a relationship so as to allow for the bullet to remain symmetrical. Otherwise a more sophisticated version of the bullet must be implemented.
FIG. 11 shows a diagrammatic side cross sectional view of the in-line transmission version of a gear shifting mechanism according to the invention. A input shaft 112 is splined at one end on the outside of a transmission housing 114 and mounted inside the housing by a set of three bearings 116 to the housing. The bearings provide the input shaft axial rotation and no lateral movement. The shaft runs through the center and is locked by a key 118 to five input (spur) gears 120 of varying circumferences and a shift cam 122. Each of the five input gears are permanently engaged by means of a gear tooth profile on there outer circumference to five output (cam) gears 124. The output gears are typical spur gears with six uniform cams 58 (FIG. 3) on there inner circumferences. The cams are comprised of three separate surfaces; a peak 60, a surface 62, and a valley 64. (FIG. 3) The peaks define the inner circumference of the output gear, and it is upon these peaks that the output gears rotate around the outer circumference of a drum portion of a output shaft 126. The drum is mounted at both ends for rotation, by bearings 128. The bearings also retain the output gears in there lateral position along their axis. The drum is hollow with three apertures 130 corresponding to each of the five output gears. The apertures extend from the inner drum surface to the outer drum surface. Each of fifteen drum apertures correspond to a detent 132. The inward bottom surface of the detents come in contact with a bullet 134. The bullet is mounted within the drum such that it has reciprocal axial movement back and forth along the drum axis. The bullet contains six outer cam surfaces 136 each having a central portion extending radially upon which the detents ride. The axial movement of the bullet is regulated by a screw shaft 138. Bolted to the other end of the drum is a output spline 140.
The gear shift lever is connected to the female portion of a union joint 144 by means of a connecting rod 142. The union end is attached to a shift actuator shaft 146 at a male union end 148. The shift actuator shaft is supported so as to provide axial rotation and reciprocal axial movement along its axis by bushings (FIG. 7 #88) which are attached to the housing. As the shift actuator shaft is pushed or pulled along its axis it engages a shift actuator gear 150 by means of fixed keys 152 on opposite sides of its circumference. The shift actuator gear has keyways 153 to receive the keys of the shift actuator shaft. The shift actuator shaft includes a actuator pinion 155. When the shift actuator shaft is moved on its axis the pinion moves an upshift rack 157 and a down shift rack referred to as shift racks. The shift racks are contained by a rack housing 159. The rack housing allows reciprocal lateral movement of the shift racks from the plate and by means of a keyway 161 (FIG. 13) on its sides allows the shift racks to move laterally along the shift actuator shaft axis. In the inward movement of the union the downshift rack and its roller moves over and in line with a downshift portion 122 of the shift cam which is affixed to the input shaft. In the pull position of the union the upshift rack and roller move over and in line with a upshift cam portion 154 of the shift cam which runs parallel to the downshift cam portion around the shift cam.
The placement and configuration of these shift cams can be advanced or retarded, to vary which cam surface is used for engagement. A robust design of the shifting mechanism can overcome if necessary the "F" and "R" to engage a detent. This option can be used to lengthen the ratio change transition. The shift racks are returned to there neutral position by a rack spring 156. The shift actuator gear has teeth on its outer circumference that engage the teeth of a shift collar 202. The center hole of the shift collar is threaded to receive the screw shaft 138. The screw shaft is held from rotating along its axis by a screw shaft washer guide 158. The screw shaft washer guide is bolted to the housing and has a key built into its inner circumference that slides in a slot 160 in the screw shaft. (shown as hidden lines in FIG. 11). | A transmission apparatus for changing the speed of a driven member relative to the speed of a driving member without interrupting the torque transfer between the members. The apparatus includes reducing gears driven by a driving member, annular cam gears in continuous engagement with the reducing gears, and a driven member which journals the cam gears for rotation. One section of the driven member is hollow and has a plurality of radially extending apertures each containing a reciprocating detent for engaging an inner cam surface or a corresponding cam gear. A shift member mounts within the bore of the driven member and moves along the rotational axis of the driven member to cause the detents to reciprocate between a cam gear engaged position and a disengaged position. By timing the movement of the shift member and the design of the cam surfaces on the cam gear, one cam gear can be simultaneously engaged while another is being disengaged to produce a gear ratio change without interrupting torque transfer between the driving and driven members. | 8 |
FIELD OF THE INVENTION
The present invention relates to a method of producing 1H-pyrazole[5,1-c]-1,2,4 triazoles which are useful as couplers for silver halide color photography.
BACKGROUND OF THE INVENTION
1H-Pyrazolo[5,1-c]-1,2,4-triazoles are compounds which are useful as couplers, especially magenta couplers, for silver salt color photography. In contrast to conventional pyrazolone type magenta couplers the novel couplers of the present invention are free from color stain attributed to side absorption which the formed dyes have in the vicinity of 430 nm. The utility thereof is described, for example, in JP-B-48-30895 (the term "JP-B" as used herein means an "examined Japanese patent publication"), U.S. Pat. No. 3,725,067, British Patent 1,252,418, Journal of the Chemical Society, Perkin I, 2047-2052 (1977), JP-A-62-209457 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), and JP-A-62-229146.
Methods for synthesizing the foregoing novel couplers are described, for example, in the above-cited Journal of the Chemical Society, U.S. Pat. No. 3,725,067, WO 86/01915, JP-A-61-18768, JP-A-62-10068, JP-A-62-10069, JP-A-62-195368, JP-A-62-209457, JP-A-62 228066, JP-A-62-229146 and JP-A-62-252773. Specific examples of methods for synthesizing the couplers include the methods disclosed in the following publications: ##STR4##
However, these methods of synthesis suffer from defect(s) such that poisonous thiocarbohydrazide has to be employed as a starting material, a yield rate of the hydrazinopyrazole produced is low, and the produced hydrazinopyrazole can have high solubility in water depending on the kind of substitutent R which makes it very difficult to handle. When using 1H-pyrazolo[5,1-c]-1,2,4-triazoles as magenta couplers for photography, additional defects include the fact that the step of eliminating X=COOEt or CN with an acid, the number of steps is increased, and what is worse, the decarboxylation reaction is difficult to control. Moreover, when R is a group other than one which is attached to the pyrazole nucleus via its carbon atom, the hydrazinopyrazole cannot be synthesized at all, or can be synthesized only in a low yield rate.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an inexpensive method of producing 1H-pyrazolo[5,1-c]-1,2,4-triazoles from safe reagents through a reduced number of steps even when a substituent group at the 6-position is attached via an atom other than carbon.
As a result of concentrating intensive studies on the solution of the problems inherent in the above-described methods of synthesis, it has now been found that 1H-pyrazolo[5,1-c]-1,2,4-triazole derivatives can be easily produced by utilizing characteristics of the nitro group which constitutes a nitroalkane compound.
Accordingly, the present invention relates to a method of producing 1H-pyrazolo[5,1-c]-1,2,4-triazoles represented by general formula (II): ##STR5## (wherein R 1 , R 2 and R 3 each represents a hydrogen atom, or a substituent group) which comprises making a compound represented by general formula (I) undergo a ring closure reaction: ##STR6## (wherein R 1 , R 2 and R 3 each represents a hydrogen atom, or a substituent group).
Further, the present invention relates to a method of producing the 1H-pyrazolo[5,1-c]-1,2,4-triazoles represented by general formula (II), wherein the compound represented by general formula (I) is prepared by reacting a compound represented by general formula (III) with a nitroalkane compound represented by general formula (IV): ##STR7## (wherein R 1 , R 2 and R 3 have the same meaning as in general formula (I); Y represents an acid radical; and n represents 0 or 1).
Furthermore, the present invention relates to a method of producing the pyrazole derivatives represented by general formula (I), wherein the compounds represented by general formula (III) are made to react with the compounds represented by general formula (IV).
DETAILED DESCRIPTION OF THE INVENTION
Each of the above-illustrated structural formulae (I), (II) and (III), corresponds to only one tautomer out of many imaginable ones. Thus, these structural formulas of the present invention are adopted with the intention of representing all tautomers that each compound can assume.
Detailed descriptions of R 1 and R 2 in general formulae (I), (II) and (III), those of R 3 in general formulae (I), (II) and (IV), and those of Y in general formula (III) are given below.
R 1 represents a hydrogen atom or a substituent group, with specific examples thereof including a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclyl group (preferably a 5- to 7-membered ring containing at least one of N, 0 and S atom as hetero atom; the same hereinafter), a cyano group, an alkoxy group, an aryloxy group, an acylamino group, an alkylamino group, an anilino group, an ureido group, a sulfamoylamino group, an alkylthio group, an arylthio group, an alkoxycarbonylamino group, a sulfonamido group, a carbomoyl group, a sulfamoyl group, a sulfonyl group, an alkoxycarbonyl group, a heterocyclyloxy group, an azo group, a acyloxy group, a carbamoyloxy group, a silyloxy group, an aryloxycarbonylamino group, an imido group, a heterocyclylthio group, a sulfinyl group, a phosphonyl group, an aryloxycarbonyl group, an acyl group and an azolyl group. These groups can be substituted. In addition, each compound may assume a bis compound which is formed by a divalent group at R 1 . (In the present invention an acyl group includes an aliphatic and aromatic acyl group, and a sulfonyl group includes an aliphatic and aromatic sulfonyl group).
More specifically, R 1 in each compound represents a hydrogen atom; a halogen atom (e.g., chlorine, bromine); an aliphatic hydrocarbon group (including 1-32 carbon straight or branched chain alkyl, aralkyl, alkenyl, alkinyl, cycloalkyl and cycloalkenyl groups, wherein each may be substituted by a group to be attached via its oxygen atom, nitrogen atom, sulfur atom or carbonyl group, hydroxyl group, nitro group, carboxyl group, cyano group or a halogen atom, e.g., methyl, ethyl, propyl, isopropyl, t-butyl, tridecyl, 2-methanesulfonylethyl, 3-(3-pentadecylphenoxy)propyl, 3-[4-{2-[4-(4-hydroxyphenylsulfonyl)phenoxy]dodecanamido}phenyl]propyl, 2-ethoxytridecyl, trifluoromethyl, cyclopentyl, 3-(2,4-di-t-amylphenoxy)propyl); an aryl group (e.g., phenyl, 4-t-butylphenyl, 2,4-di-t-amylphenyl, 4-tetradecanamidophenyl); a heterocyclyl group (e.g., 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl); cyano group; an alkoxy group (e.g., methoxy, ethoxy, 2-methoxyethoxy, 2-dodecylethoxy, 2-methanesulfonylethoxy); an aryloxy group (e.g., phenoxy, 2-methyl phenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 3-t-butyloxycarbamoylphenoxy, 3-methoxycarbamoylphenoxy); an acylamino group (e.g., acetamido, benzamido, tetradecanamido, α-(2,4-di-t-amylphenoxy)butanamido, γ-(3-t-butyl-4-hydroxyphenoxy)butanamido, α-{4 (4 hydroxyphenylsulfonyl)phenoxy}decamido); an alkylamino group (e.g., methylamino, butylamino, dodecylamino, diethylamino, methylbutylamino); an anilino group (e.g., phenylamino, 2-chloroanilino, 2-chloro 5 tetradecanaminoanilino, 2-chloro-5-dodecyloxycarbonylanilino, N-acetylanilino, 2-chloro-5-{α-(3-t-butyl-4-hydroxyphenoxy) dodecanamido}anilino); an ureido group (e.g., phenylureido, methylureido, N,N-dibutylureido); a sulfamoylamino group (e.g., N,N-dipropylsulfamoylamino, N-methyl N-decylsulfamoylamino); an alkylthio group (e.g., methylthio, octylthio, tetradecylthio, 2-phenoxyethylthio, 3-phenoxypropylthio, 3-(4-t-butyl-phenoxy)propylthio); an arylthio group (e.g., phenylthio, 2-butoxy-5-t-octylphenylthio, 3-pentadecylphenylthio, 2-catboxyphenylthio, 4-tetradecanamidophenylthio); an alkoxycarbonylamino group (e.g., methoxycarbonylamino, tetradecyloxycarbonylamino); a sulfonamido group (e.g., methanesulfonamido, hexadecane sulfonamido, benzenesulfonamido, p-toluenesulfonamido, octadecanesulfonamido, 2-methyloxy-5-t-butylbenzenesulfonamido); a carbamoyl group (e.g., N-ethylcarbamoyl, N,N-dibutylcarbamoyl, N-(2-dodecyloxyethyl)carbamoyl, N-methyl-N-dodecylcarbamoyl, N-{3-(2,4-di-t-amylphenoxy)propyl}carbamoyl); a sulfamoyl group (e.g., N-ethylsulfamoyl, N,N-dipropylsulfamoyl, N-(2-dodecyloxyethyl)-sulfamoyl, N-ethyl-N-dodecylsulfamoyl, N,N-diethylsulfamoyl); a sulfonyl group (e.g., methanesulfonyl, octanesulfonyl, benzenesulfonyl, toluenesulfonyl); an alkoxycarbonyl group (e.g., methoxycarbonyl, butyloxycarbonyl, dodecyloxycarbonyl, octadecyloxycarbonyl); a heterocycloxy group (e.g., 1-phenyltetrazole-5-oxy, 2-tetrahydropyranyloxy); an azo group (e.g., phenylazo, 4-methoxyphenylazo, 4-pivaloylaminophenylazo, 2-hydroxy-4-propanoylphenylazo); an acyloxy group (e.g., acetoxy); a carbamoyloxy group (e.g., N-methylcarbamoyloxy, N-phenylcarbamoyloxy); a silyloxy group (e.g., trimethylsilyloxy, dibutylmethylsilyloxy); an aryloxycarbonylamino group (e.g., phenoxycarbonylamino); an imido group (e.g., N-succinimido, N-phthalimido, 3-octadecenylsuccinimido), a heterocyclthio group (e.g., 2-benzothiazolylthio, 2,4-di-phenoxy-1,3,5-triazole-6-thio, 2-pyridylthio); a sulfinyl group (e.g., dodecanesulfinyl, 3-pentadecylphenylsulfinyl, 3 phenoxypropylsulfinyl,); a phosphonyl group (e.g., phenoxyphosphonyl, octyloxyphosphonyl, phenylphosphonyl); an aryloxycarbonyl group (e.g., phenoxycarbonyl); an acyl group (e.g., acetyl, 3-phenylpropanoyl, benzoyl, 4-dodecyloxybenzoyl), or an azolyl group (e.g., imidazolyl, pyrazolyl, 3-chloropyrazole-1-yl, triazolyl).
Among these substituent groups, those preferred as R 1 include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an ureido group, an alkoxycarbonylamino group, an aryloxycarbonylamino group and an acylamino group.
R 2 includes the same substituent groups as cited above as examples of R 1 , and those preferred as R 2 include a halogen atom, an alkyloxy group, an aryloxy group, an alkylthio group, an arylthio group, an azo group and an azolyl group.
R 3 includes the same substituent groups as cited above as examples of R 1 , and those preferred as R 3 are specifically a hydrogen atom, an alkyl group, an aryl group, a heterocyclyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group and a cyano group. Of these groups, a hydrogen atom, an alkyl group, an aryl group and a heterocyclyl group are preferred.
Y represents an inorganic or an organic acid radical. Suitable examples of an inorganic acid radical include hydrochloric acid radical, hydrobromic acid radical, sulfuric acid radical, nitric acid radical and so on, and examples of an organic acid radical include acetic acid radical, trifluoroacetic acid radical, trichloroacetic acid radical, dichloroacetic acid radical, methanesulfonic acid radical, trifluoromethanesulfonic acid radical, benzenesulfonic acid radical, p-toluenesulfonic acid radical and so on.
Pyrazolo[5,1-c]-1,2,4-triazole compounds represented by general formula (II) in the present invention are mainly employed as magenta couplers for photography. However, it is to be understood herein that their use is not limited to the above-described one. Therefore, a group capable of splitting off upon the reaction with the oxidation product of a developing agent (which is hereinafter simply called a splitting off group) has considerable significance as the group represented by R 2 , but R 2 may be converted to a splitting-off group afterwards. So far as the method of synthesis for the present invention are concerned, it goes without saying that R 2 may or may not be a splitting-off group.
Specific examples of 1H-pyrazolo[5,1-c]-1,2,4-triazoles represented by general formula (II) which can be synthesized by the methods of the present invention are illustrated below. However, the invention should not be construed as being limited to these representative examples. ##STR8##
Now, various embodiments of the present invention are described below in detail.
The synthesis process of the present invention is shown using reaction steps represented by scheme (1): ##STR9##
In the above reaction scheme (1), R 1 , R 2 , R 3 and Y in general formulae (I), (II), (III) and (IV) have the same meaning as described hereinbefore, respectively. R 1 and R 2 in general formula (V) have the same meaning as in the general formula (III), respectively. Y', though it has the same meaning as Y, may be the same as or different from Y. represents 0 or 1, and n also represents 0 or 1.
The compounds represented by general formula (III) can be synthesized in accordance with the methods illustrated, for example, in Chemical Reviews, vol. 75, No. 2. pp. 241 to 257 (1975), Journal of Heterocyclic Chemistry, vol, 18, p. 675 (1981), Chemische Berichte, vol. 117, pp. 1726 to 1747 (1984), JP-A-62-10068, JP-A-62-10069, JP-A-62-195368, JP-A-62-228066, JP-A-62-229146 and JP-A-62-252773, and the methods described in the references cited from the above-described publications and patent specifications.
The compounds represented by general formula (III) are obtained in the form of a solution in water or in an organic solvent, usually containing excess HY, or in the form of solution in HY itself when HY is an organic acid which is in a liquid state at room temperature. These compounds correspond to the case of n=1 in general formula (III). These solutions may be used in the subsequent reaction of the present invention as they are, or after conversion to the diazoazole compounds corresponding to the case of n=0 by a neutralization treatment according to a conventional method, they may be used in the reaction of this invention.
The aminopyrazoles represented by general formula (V) can be synthesized in accordance with the methods described, for example, in the above-cited patents, publications, and references quoted therefrom, and also JP-B-45-22328 (the term "JP-B" as used herein means an "examined Japanese patent publication"), JP-B-48-2541, Takeda Kenkyusho Ho, 30, 475 (1971) and JP-A-62-209457.
The derivation to the diazonium salts represented by general formula (III) from the aminopyrazoles represented by general formula (V) can be effected in accordance with such a known method as to use, for example, sodium nitrite, isoamyl nitrite or the like.
The nitroalkane compounds represented by general formula (IV) are readily available depending on the kind of R 3 (e.g., when R 3 is a hydrogen atom, a methyl group, an ethyl group or the like), or can be easily synthesized according to conventional methods described, for example, in Journal of the American Chemical Society, 76, 3209 (1954), Supra, 78, 1497 (1956), Journal of Organic Chemistry, 22, 455 (1957), Supra, 43, 3101 (1978), Journal of the Chemical Society Chemical Communication, 362 (1978).
The reaction of synthesizing the compounds represented by general formula (I) from the compounds represented by general formula (III) and the compounds represented by general formula (IV) is described below in detail.
The compounds represented by general formula (IV) are preferably used in an amount of from 0.5 to 5 equivalents, particularly from 0.8 to 3.0 equivalents, relative to the compounds represented by general formula (III).
The reaction solvent to be used may be chosen from any type of solvent, whether it is protic or aprotic, and whether it has high polarity or not, if desired. The solvent may be a mixture of two or more different types of solvents.
Examples of preferred reaction solvents include sulfone solvents such as sulforan, etc., sulfoxide solvents such as dimethyl sulfoxide, etc., amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, etc., urea solvents such as N,N,N',N'-tetramethylurea, etc., alcohol solvents such as methanol, ethanol, isopropyl alcohol, tert-butanol, etc., ether solvents such as tetrahydrofuran, dioxane, etc., halogenated hydrocarbon solvents such as methylene chloride, chloroform, dichloroethane, etc., basic solvents such as triethylamine, pyridine, etc., nitrile solvents such as acetonitrile, etc., aromatic hydrocarbons such as benzene, toluene, xylene, etc., and so on. Of these solvents, alcohol solvents and aide solvents such as N,N-diemthylformamide and N,N-dimethylacetamide are preferred over the others.
A preferred reaction temperature range is from -20° C. to 100° C., and more particularly is from -10° C. to 40° C.
Bases which may be used are those capable of dissociating a proton located at the α-position of the nitroalkane. Suitable examples thereof include metal hydroxides such as sodium hydroxide, potassium hydroxide, etc., metal salts of alcohols such as sodium methoxide, potassium tert-butoxide, etc.; metal hydrides such as sodium hydride, etc., organometallic compounds such as butyl lithium, methylmagnesium iodide, etc.; metal amide compounds such as lithium diisopropylamide, etc.; alkali metals such as sodium, potassium, etc., and organic bases such as pyridine, triethylamine, etc. Of these bases, sodium hydroxide, sodium methoxide and sodium hydride are preferred over the others.
Although the amount of a base to be used depends on the basicity thereof, it is desirable that the base should be used in an amount which is enough to render the pH of the reaction system within the range of from 7 to 14 even at the conclusion of that reaction.
The reaction time is preferably in the range of from 5 minutes to 10 hours, and more preferably is from 5 minutes to 3 hours. However, the reaction conditions employable herein should not be construed as being limited to the above-described conditions.
Some of the thus obtained compounds of general formula (I) are difficult to isolate because of their instability. In such cases, the reaction product may be subjected to the next reaction as it is without being isolated.
Finally, the reaction for synthesizing the compounds represented by general formula (II) from the compounds represented by general formula (I) is described below in detail.
The synthesis of the compounds of general formula (II) through the ring closure reaction of the compounds of the general formula (I) is preferably carried out in the presence of a base.
Bases which may be used in the above-described synthesis include inorganic and organic ones, preferably those bases capable of dissociating a proton situated in the α-position of the nitroalkanes, and more preferably sodium hydroxide, sodium methoxide, and so on.
A suitable quantity of the base which may be used is in the range of 0.5 to 5 equivalents, and preferably is in the range of 0.8 to 3 equivalents with respect to the compound represented by formula (I).
Reaction solvents which may be used in this reaction include water, and those solvents used for the synthesis of the compounds of general formula (III), preferably water and alcoholic solvents.
The reaction temperature is preferably in the range of from 10° C. to 150° C., more preferably is from room temperature to 120° C., and particularly preferably is from room temperature to 100° C.
The reaction time is preferably in the range of from 15 minutes to 48 hours, more preferably is from 30 minutes to 24 hours, and particularly preferably is from 30 minutes to 12 hours. However, this reaction should not be construed as being limited to these conditions.
Although 1H-pyrazolo[1,5-c]-1,2,4-triazole derivatives prepared by the reaction steps represented by scheme (1) can be separated from the reaction solution in a conventional manner, they can be used as a starting material of a subsequent reaction without undergoing any isolation step, if desired. Examples of isolation means which can be properly used include the usual recrystallization techniques, solvent extraction, filtration, column chromatography, thin layer chromatography and so on. These techniques may be employed independently or in combination.
In accordance with the method of this invention, 1H-pyrazolo[1,5-c]-1,2,4 triazole derivatives represented by general formula (II) can be synthesized in a shortened process, compared with conventional methods. In addition, 1H-pyrazolo[1,5-c]1,2,4-triazoles having various kinds of substituent groups at their respective 6-positions can be easily synthesized.
Accordingly, synthesizing costs can be reduced and, at the same time, replacement of a substituent group located at the 6-position can be facilitated, resulting in an enhancement of the utility value of these 1H-pyrazolo[1,5-c]-1,2,4-triazole derivatives as photographic couplers.
The present invention will now be illustrated in greater detail by reference to the following examples. However, the invention should not be construed as being limited to these examples.
Example 1 ##STR10##
A 38 ml portion of 36% hydrochloric acid was added to 8.61 g (4.07×10 -2 mol) of 5-amino-3-phenoxypyrazole hydrochloride (1), and cooled in an ice bath. 3.43 ml (4.27×10 -2 mol) of sulfuryl chloride was slowly added dropwise thereto while stirring to synthesize compound 2. The reaction solution was stirred for an additional one hour as it was, and a solution of 2.95 g (4.27×10 -2 mol) of sodium nitrite in 5.9 ml of water wa gradually added dropwise thereto. The reaction mixture was further stirred for 1.5 hours, resulting in the production of compound 3. A solution of the thus produced compound 3 was slowly added dropwise to a solution while stirring and cooling with ice, said solution having been prepared by adding 102 ml of 28% sodium methylate to a solution of 9.58 g (4.27×10 -1 mol) of compound 4 in 177 ml of ethanol while stirring and cooling with ice (during the addition, the reaction solution turned dark orange), and the stirring was further continued for 1 hour (to synthesize the compound 5). Then, the reaction solution was heated while stirring under reflux for 1.5 hours. Thereafter, ethanol was distilled away from the reaction solution under reduced pressure, and the residue was dissolved in chloroform, washed with a saturated aqueous solution of sodium chloride, dried over Glauber's salt, and chloroform was distilled away under reduced pressure. The residue was purified by column chromatography (eluate: chloroform/ethyl acetate), and further by recrystallization from a chloroform/hexane mixture to yield 6.90 g of the exemplified compound (1) as a colorless crystal (yield rate: 43% based on compound 1). Data of physical properties of the thus produced exemplified compound (1) are shown below.
Melting Point: 155° to 156.5° C.
1 H-NMR Spectrum (CDCl 3 ): δ=2.23 (m, 2H), 2.82 (t, 2H), 2.96 (t, 2H), 7.1 to 7.4 (m,7H), 8.12 (d, 2H), 9.18 (brs. 1H).
Mass Spectrum: m/e 397 (M + )
Finally, the compound 4 was synthesized from compound a, which had been prepared from γ-lactone and benzene in a known manner, according to the method described in Journal of the American Chemical Society, vol. 76, p. 3209 (1954) ##STR11##
EXAMPLE 2
Synthesis of Exemplified Compound (2) ##STR12##
An 8.6 ml portion of 36% hydrochloric acid was added to 1.05 g (3.83 mmol) of 5-amino-4-chloro-3-(2.4-dimethylphenoxy)pyrazole hydrochloride (6) under cooling. A solution of 2.9×10 -1 g (4.21 mmol) of sodium nitrite in 0.6 ml of water was slowly added dropwise thereto, and was stirred for an additional one hour to synthesize compound 7. Then, a solution of the thus produced compound 7 was slowly added dropwise to a reactant solution, which had been prepared by adding 3.98 g (9.96×10 -2 mol) of sodium hydroxide to a methanol solution containing 3.6×10 -1 g (4.02 mmol) of compound 8, while stirring and cooling with ice. The reaction mixture was stirred for an additional one hour. During the addition, the reaction solution turned dark orange. Thereafter, ethanol was distilled away from the reaction solution under reduced pressure, and the residue was dissolved in ethyl acetate, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled therefrom under reduced pressure to obtain 1.60 g of solid containing compound 9. This solid (containing 1.60 g of compound 9) was dissolved in 40 ml of ethanol, and heated while stirring under reflux for 2 hours. Thereafter, ethanol was distilled away under reduced pressure, and the residue was admixed with ethyl acetate, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled away under reduced pressure, and the solid obtained was recrystallized from a chloroform/hexane mixture to obtain 0.28 g of a colorless, crystalline compound (exemplified compound (2)). The yield rate was 25% based on compound 6. Data of physical properties of the thus produced exemplified compound (2) are shown below.
Melting Point: 150° to 153°
1 H-NMR Spectrum (DCDl 3 ): δ=1.38 (t, 3H), 2.24 (s, 3H), 2.31 (s, 3H), 2.90 (q, 2H), 6.9 to 7.1 (m, 3H), 9.43 (brs. 1H).
Mass Spectrum: m/e 290 (M + )
EXAMPLE 3
Synthesis of Exemplified Compound (3) ##STR13##
A 51 ml portion of 36% hydrochloric acid was added to 8.56 g (5.09×10 -2 mol) of 5-amino-3-methylpyrazole hydrochloride (10), and a solution of 3.69 g (5.35×10 -2 mol) of sodium nitrite in 7.4 ml of water was added dropwise thereto over a 30-minute period while stirring and cooling with ice. The reaction mixture was further stirred for 1 hour. The thus obtained solution containing compound 11 was named Solution (1). Solution (1) was added dropwise over a 35-minute period to a reactant solution, which had been prepared by adding 7.32 ml (1.02×10 -1 mol) of nitroethane (12) to a solution of 26.5 g (6.62×10 -1 mol) of sodium hydroxide in a mixture of 106 ml of ethanol with 53 ml of water while stirring and cooling in an ice bath, and then stirring the admixture for 30 minutes. The resulting reaction mixture was stirred for an additional 2 hours as it was cooled in an ice bath. During the stirring, the reaction solution turned dark orange (to produce compound 13). Then, the reaction solution was heated while stirring under reflux for 2.5 hours. Thereafter, ethanol was distilled away from the reaction solution under reduced pressure, and the residue was extracted with ethyl acetate, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled therefrom under reduced pressure to yield 7.0 g of the exemplified compound (3) as crude crystals (crude yield rate: 81% based on compound 10). These crude crystals were purified by silica gel column chromatography (eluate: chloroform/methanol), and further by recrystallization from hot acetonitrile to yield 2.20 g of exemplified compound (3) as colorless crystals (yield rate: 25% based on compound 10). Data of the physical properties of the thus produced exemplified compound (3) are shown below.
Melting Point: decomposed at 202° to 238° C. (in a sealed tube)
1 H-NMR Spectrum (CDCl 3 ): γ=2.38 (s, 3H), 2.59 (s, 3H), 9.30 (brs. 1H).
Mass Spectrum: m/e 170 (M + )
EXAMPLE 4
Synthesis of Exemplified Compound (4) ##STR14##
Synthesis of Compound 15
A mixture of 255 g (2.20 mol) of compound 14, 180 g (4.40 mol) of acetonitrile and 200 ml of tetrahydrofuran was added dropwise for a one-hour period to a solution of 322 g (2.42 mol) of t-butoxy potassium in 1.3 liters of tetrahydrofuran while heat-refluxing and stirring, and then heated while stirring under reflux for 4 hours.
Thereafter, the reaction solution was poured into water, and the pH thereof was adjusted to below 7 by adding 36% hydrochloric acid. The reaction product was extracted with ethyl acetate, and dried over Glauber's salt. Then, ethyl acetate was distilled away therefrom under reduced pressure. Thus, 190 g of compound 15 was obtained as crude crystal.
Synthesis of Compound 16
1.5 Liters of ethanol and 500 ml of isopropanol were added to 190 g (1.52 mol) of the crude crystal of compound 15, and 114 g (1.82 mol) of hydrazine monohydrate was further added dropwise at room temperature while stirring. The resulting mixture was heated while stirring under reflux for 6 hours. Thereafter, the insoluble matter was filtered out, and from the filtrate ethanol and isopropanol were distilled away under reduced pressure. To 213 g of the thus obtained residue was added 800 ml of glacial acetic acid, and 245 g (1.53 mol) of bromine was further added dropwise while stirring at a temperature of below 30° C. The reaction mixture was stirred for an additional one hour.
Thereafter, the insoluble matter was filtered out, and the acetic acid was distilled away from the filtrate under reduced pressure. The resulting residue was recrystallized from hot ethyl acetate to obtain 343 g of compound 16 as pale yellow crystal (yield rate: 52% based on compound 14). Data of the physical properties of the thus obtained compound 16 are shown below.
Melting Point: 178° to 183.5° C.
1 H-NMR Spectrum (DMSO-d 6 ): γ=1.37 (s, 9H), 9.95 (brs. 4H).
Mass Spectrum: m/e 217, 219 (M + , 1:1)
Elemental Analysis:
Calcd. (as C 7 H 13 N 3 Br 2 ): C 28.12; H 4.38; N 14 05; Br 53.45.
Found : C 28.06; H 4.16; N 14.17; Br 53.37.
Synthesis of Compound 18
A 90 ml portion of 36% hydrochloric acid was added to 26.9 g (8.98×10 -2 mol) of compound 16, and slowly added dropwise thereto was a solution of 6.51 g (9.43×10 -2 mol) of sodium nitrite in 13 ml of water while stirring and cooling with ice. The reaction mixture was further stirred for 2 hours. The thus obtained solution containing compound 17 was named Solution (1). Solution (1) was added dropwise over a 30-minute period to a reactant solution, which had been prepared by adding 12.9 ml (1.79×10 -1 mol) of nitroethane to a solution of 46.7 g (1.17 mol) of sodium hydroxide in a mixture o 187 ml of dimethylformamide with 93 ml of water while stirring and cooling with ice, and then stirring the admixture for 30 minutes (during the stirring, white precipitates separated out of the reaction solution). The resulting reaction mixture was stirred for an additional 40 minutes while cooling with ice. During the stirring, the reaction solution turned dark orange. Thereafter, the reaction solution was adjusted to a pH of about 5 by the addition of 12 ml of 36% hydrochloric acid, and then water was added to precipitate crystals. These crystals were filtered off, and the filtrate was extracted once with ethyl acetate. The separated crystals were added to the extract, and dissolved therein. The resulting solution was washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled away under reduced pressure, and the thus obtained residue was recrystallized from an ethyl acetate/hexane mixture to yield 18.4 g of compound 18 as orange crystals (crude yield rate: 67% based on compound 16). Data of physical properties of the thus produced compound 18 are shown below.
Melting Point: 119° to 121° C. (decomposed)
1 H-NMR Spectrum (CDCl 3 ): γ=1.40 (s, 9H), 2.44 (s, 3H), 12.09 (brs. 1H).
Mass Spectrum: m/e 303, 305 (M + , 1:1)
Elemental Analysis
Calcd. (as C 9 H 14 N 5 O 2 Br): C 35.44; H 4.64; N 23.03; Br 26.27.
Found : C 35.41; H 4.49; N 23.12; Br 26.29.
Synthesis of Exemplified Compound (4)
A 6.7 ml portion of 28% sodium methylate was added to a solution of 5.07 g (1.67×10 -2 mol) of compound 18 in 76 ml ethanol, and heated while stirring under reflux for 8 hours. Thereafter, the reaction mixture was diluted with water, and then methanol and ethanol were distilled away therefrom under reduced pressure. The resulting residue was dissolved in ethyl acetate, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled away therefrom under reduced pressure. The thus obtained residue was purified by silica gel column chromatography (eluate: hexane/ethyl acetate) to yield 2.80 g of the exemplified compound (4) as pale yellow crystals (yield rate: 65% based on compound 18). Further, these crystals were recrystallized from hot acetonitrile to obtain 1.35 g of exemplified compound (4) as colorless crystals (yield rate: 31.5% based on compound 18). Data of physical properties of the thus produced compound (4) are shown below.
Melting Point: 182° to 189° C. (decomposed)
1 H-NMR Spectrum (CDCl 3 ): γ=1.49 (s, 9H), 2.62 (s, 3H), 9.41 (brs. 1H).
Mass Spectrum: m/e 251, 253 (M + , 1:1)
Elemental Analysis
Calcd. (as C 9 H 13 N 4 Br):C 42.04; H 5.10; N 21.79; Br 31.07.
Found : C 42.02; H 4.98; N 21.82; Br 31.06.
EXAMPLE 5
Synthesis of Exemplified Compound (5) ##STR15##
3 ml of methanol and 2.86 ml of 36% hydrochloric acid were added to 1.00 g (3.44 mmol) of compound 19, and 0.51 ml (3.78 mmol) of isoamyl nitrite was further added while stirring and cooling with ice. The reaction mixture was stirred for an additional 2.5 hours, and then the precipitated crystals were filtered off, and washed with water. These crystals (compound were added to a mixture of 0.49 ml (6.87 mmol) of nitroethane, 1.38 ml of 28% sodium methylate and 10 ml of ethanol while stirring and cooling with ice, and then further stirred for 2 hours. (During the stirring, the reaction solution turned dark orange to produce compound 21). Then, the reaction solution was heated while stirring under reflux for 2.5 hours.
Thereafter, ethanol was distilled away from the reaction solution under reduced pressure, and the residue was dissolved in ethyl acetate, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled away under reduced pressure to obtain an oily matter containing 0.82 g of exemplified compound (5). The thus obtained oily matter was purified by silica gel column chromatography (eluate: hexane/ethyl acetate), and further by recrystallization from hot acetonitrile to yield 54 mg of exemplified compound (5) (yield rate: 5.3% based on compound 19). Data of properties of the thus produced exemplified compound (5) are shown below.
Melting Point: 202° to 205° C. (decomposed)
1 H-NMR Spectrum (DMSO-d 6 ): γ=2.10 (s, 3H), 7.6 to 7.8 (m, 2H), 7.99 (s, 1H), 8.07 (d, 2H), 13.34 (brs. 1H).
Mass Spectrum: m/e 293 (M + , 1:1)
EXAMPLE 6 ##STR16##
A solution of 0.56 g (8.11 mmol) of sodium nitrite in 1.2 ml of water was added dropwise to a solution of 2.31 g (7.73 mmol) of compound 16 in 7.7 ml of 36% hydrochloric acid, and the stirring was continued for one hour. 30 ml of methylene chloride was added to the reaction mixture, and further a suspension of 9.3 g (1.11×10 -2 mol) of sodium hydrogen carbonate in 30 ml of water was added to adjust the pH to about 7 and to separate the mixture into liquid phases. After the methylene chloride phase was dried over Glauber's salt, the salt was filtered out to obtain a methylene chloride solution of compound 22.
0.22 g (9.27 mmol) of sodium hydride (60% dispersion in oil) was added to a solution of 3.76 g (9.27 mmol) of compound 23 in 38 ml of tetrahydrofuran, and stirred for 30 minutes to prepare a reactant solution. The foregoing methylene chloride solution of compound 22. was added dropwise thereto while stirring and cooling with ice, and the resulting reaction mixture was stirred for an additional one hour. During the stirring, the reaction solution turned dark orange.
Thereafter, methylene chloride and tetrahydrofuran were distilled away from the reaction solution under reduced pressure, and to the residue methylene chloride was added, washed with a saturated aqueous solution of ammonium chloride, and dried over Glauber's salt. The methylene chloride was distilled away under reduced pressure at a temperature of below 30° C. to obtain 8.40 g of oily matter containing compound 24.
This oily matter was dissolved into 49 ml of ethanol, and 3.1 ml of 28% sodium methylate was added thereto. The reaction solution was heated while stirring under reflux for 11 hours. The ethanol was then distilled away under reduced pressure, and to the residue ethyl acetate was added, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Thereafter, the ethyl acetate was distilled away to obtain 5.39 g of oily matter containing exemplified compound (6). This oily matter was purified by silica gel column chromatography (eluate: hexane/ethyl acetate) to yield 1.0 g of exemplified compound (6) as crystals colored slightly by contamination with impurity (yield rate: 22% based on compound 16). Data of physical properties of the thus obtained compound (6) are shown below.
Melting Point: 56° to 59° C.
1 H-NMR Spectrum (CDCl 3 ): δ=6 0.88 (t, 3H), 1.1 to 1.7 (m, 26H), 1.47 (s, 9H), 2.3 to 2.5 (m, 2H), 2.58 (t, 2H), 3.18 (t, 2H), 4.07 (t, 2H), 6.65 to 6.8 (m, 3H), 7.16 (dd, 1H), 9.08 (brs, 1H).
Mass Spectrum: m/e 585 (M-1) + , (EI-Mass).
In addition, compound 23 was synthesized from compound (b), which had been prepared from cardanol and γ-lactone in a known manner, according to the method described in Journal of the American Chemical Society, vol. 76, p. 3209 (1954): ##STR17##
REFERENCE EXAMPLE
Compounds useful as photographic couplers were derived from the 1H-pyrazolo[5,1-c]-1,2,4-triazoles synthesized in accordance with this invention. For instance, the synthesis of coupler (1) illustrated below which is derived from exemplified compound (1) is described below in detail: ##STR18##
Synthesis of Compound 28
4.2 ml of water, 0.13 g (2.48×10 -3 mol) and 0.14 ml (2.48×10 -3 mol) of acetic acid were added to 1.38 g (2.48×10 -2 mol) of reduced iron powder, and the resulting mixture was heated while stirring under reflux for 15 minutes. 13 ml of isopropanol was added thereto, and the heating while stirring under reflux was further continued for 20 minutes. A solution of 1.97 g (4.95×10 -3 mol) of exemplified compound (1) in 5.9 ml of isopropanol was added dropwise thereto, and heated while stirring under reflux for 2 hours. Thereafter, the reaction solution was filtered using Celite as a filter aid, and the filtrate was diluted with chloroform, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. The chloroform was distilled away under reduced pressure to obtain 1.70 g of compound 28 as a crude product.
Synthesis of Coupler (1)
5.1 ml of dimethylacetamide was added to a solution of 1.70 g (4.62×10 -3 mol) of crude compound 28 in 8.5 ml of tetrahydrofuran. 2.17 g (6.01×10 -3 mol) of compound 29 was added first thereto, followed by the addition of 0.49 ml (6.01×10 -3 mol) of pyridine while stirring and cooling with ice. The resulting mixture was stirred for 1.5 hours at room temperature, and then diluted with ethyl acetate, washed with a saturated aqueous solution of sodium chloride, and dried over Glauber's salt. Ethyl acetate was distilled away therefrom under reduced pressure to obtain 4.10 g of Coupler (1) as a crude product. The crude product was purified by silica gel column chromatography (eluate: chloroform/ethyl acetate), and recrystallized from hot acetonitrile to yield 1.28 g of Coupler (1) as colorless crystals (yield rate: 37% based on exemplified compound (1)). Data of physical properties of the thus obtained coupler are shown below.
Melting Point: 101° to 102° C.
1 H-NMR Spectrum (CDCl 3 ): δ=0.90 (t, 3H), 1.1 to 1.5 (m, 20H), 1.7 to 1.9 (m, 2H), 2.0 to 2.2 (m, 2H), 2.52 (t, 2H), 2.90 (t, 2H), 3.92 (t, 2H), 6.8 to 7.4 (m, 12H), 7.66 (d, 2H), 9.83 (brs, 1H).
Mass Spectrum: m/e 691 (M + )
Elemental Analysis
Calcd. (as C 37 H 46 N 5 O 4 SCl): C 64.19; H 6.70; N 10.12; Cl 5.12; S 4.63
Found: C 64.24; H 6.64; N 10.01; Cl 5.14; S 4.63
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A method of producing 1H-pyrazolo[5,1-c]-1,2,4-triazoles represented by general formula (II): ##STR1## (wherein R 1 , R 2 and R 3 each represents a hydrogen atom or a substituent group) which comprises making a compound represented by general formula (I) undergo a ring closure reaction: ##STR2## (wherein R 1 , R 2 and R 3 each represents a hydrogen atom, or a substituent group), and a method of producing a pyrazol derivative represented by general formula (I) by reacting a compound represented by general formula (III) and general formula (IV): ##STR3## wherein R 1 , R 2 and R 3 have the same meaning as in general formula (I); Y represents an acid radical; and n represents 0 to 1. | 2 |
This application is a continuation of international application Ser. No. PCT/FI99/00174, filed 5 Mar. 1999.
FIELD OF THE INVENTION
The invention concerns routing of a data transmission connection between a piece of terminal equipment and a host over a data transmission network.
TECHNICAL BACKGROUND
Mobile use of various personal computers, e.g. PDA (Personal Digital Assistant) and intelligent telephones, has become increasingly popular. Using such terminal equipment the user is in connection with the host, both in the office and outside the office. Some modern user interfaces for terminal equipment, such as Windows 95, allow connection and disconnection of so-called plug-and-play accesses even while the application is running.
It is known in the state of the art to choose the routing at nodal points of a network. FIG. 1 in the appended drawing shows how a piece of terminal equipment is connected through an intermediary network (internet) to a host in a known manner. E.g. when moving outside the office in situation 1 , terminal equipment TE connects with the AP 1 (Access Point). In the messages which it sends, the terminal equipment uses as source address the address reserved by the access point for the terminal equipment. A node wishing to be in connection with the terminal equipment will for its part use said address as destination address for messages which it sends. When the access point is changed, this address will be exchanged, e.g. in the situation 2 shown in FIG. 1 for the address reserved by access point AP 2 . By using e.g. the Mobile IP protocol, the access point used currently by the user may be registered in the HA (home agent), which allows use of the same address irrespective of the access point. However, the user must choose manually the access point to be used at each time. It is not possible in this arrangement to exchange the access point automatically for another access point while terminal equipment TE is moving, e.g. to replace AP 1 with AP 2 , but the terminal equipment must itself actively connect and register with anew access point in order to bring about the connection. The user can be connected with one access point at a time.
The connection from terminal equipment TE is set up using the available access. Various network accesses are e.g. the Ethernet or IR (infra-red) at the office or the GSM (Global System for Mobile Communications) data access, especially the GPRS (General Packet Radio Service) access, outside the office. One generally used way of access is by connecting a PCMCIA access card to terminal equipment TE. The user may remove and connect these accesses as he desires, whereby the connection is set up by way of the access which is connected at each time. Several cards may also be connected at the same time to terminal equipment TE, but hereby only one of them is used, e.g. the access which was connected first to the terminal equipment, and the access is not exchanged automatically for another while the connection is in use, even if the connection through the used access is lost.
It is a problem with state-of-the-art accesses that the connection of the terminal equipment with the data network is not flexible. The user must himself actively carry out the choice of the access to be used as well as its connection and registration with the network nodal point. In addition, when exchanging the access it is sometimes necessary to close the application and to restart the system in order to begin using a new access.
SUMMARY OF THE INVENTION
An objective of this invention is to bring about a flexible system using different network accesses and a method for routing a data transmission connection between the terminal equipment and the host.
This new type of routing a data transmission connection is achieved by methods according to the invention which are characterised by what is said in independent claims 1 and 15 . Preferable embodiments of the methods are presented in the dependent claims.
In addition, the invention concerns arrangements, which according to the invention are characterised by what is said in independent claims 26 , 28 and 30 .
The invention is based on the idea that the first routing of the connection between the terminal equipment and the host is carried out in the terminal equipment and/or in a gateway exchange located between the terminal equipment and the host, according to criteria established in advance. In a first alternative embodiment of the invention, a router located in the terminal equipment monitors the access points currently available according to pre-established criteria for the routing of the data transmission. Based on the results of this monitoring, the router of the terminal equipment will route the data transmission traffic by way of at least one access point meeting the criteria in the desired manner. According to the criteria set up in the different embodiments, the router of the terminal equipment selects at least one routing alternative from at least two different access points and/or divides the traffic proportioned between at least two access points. The terminal equipment connects the chosen access/the chosen accesses with the application of the terminal equipment, preferably transparently from the viewpoint of the application and the user. Of the routing alternatives one may also choose more than one access for connection to the application simultaneously, whereby the data transmission will take place through several transmission connections, e.g. in order to ensure the data transmission. Criteria established in advance are e.g. the transmission capacity, transmission delays, transmission errors, data security and/or the costs of data transmission. The application may also set up these criteria. In the other alternative embodiments of the invention, the first routing is performed to the terminal equipment according to pre-established criteria in the terminal equipment and in the gateway exchange or only in the gateway exchange.
It is an advantage of such a method that it allows to choose the access which is most advantageous for the user, e.g. the cheapest access or one which gives the best performance.
It is another advantage of the method according to the invention that change of the access and use of accesses can be carried out in a manner which is transparent to the user and/or the application, keeping up an essentially continuous connection. No changes need be made in existing connecting methods.
It is also an advantage of the method according to the invention that it allows data security for the data transmission connection from one end to the other as well as data compression when required.
It is an advantage of the arrangement according to the invention that it does not require any special application or any changes to state-of-the-art applications, but it can be used when using existing applications. Nor need any changes be made in existing access points or in the transmission network.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail in connection with preferable embodiments and referring to the examples shown in FIGS. 2-6 of the appended drawings, wherein:
FIG. 1 shows a state-of-the-art connection of a piece of terminal equipment to a host over a data transmission network;
FIG. 2 shows a connection of a piece of terminal equipment to a host over a data transmission network in accordance with the invention;
FIG. 3 is a flow chart of a primary embodiment of the invention;
FIG. 4 shows a case by way of example of a primary embodiment of the invention wherein data packages are relayed through network access points in accordance with the invention;
FIG. 5 is a flow chart of a secondary embodiment of the method according to the invention; and
FIG. 6 shows the structure of a piece of terminal equipment according to the invention at protocol level.
DETAILED DESCRIPTION OF THE INVENTION
The present invention may be applied in connection with any data transmission system. The invention will be described in greater detail hereinafter in the light of preferable embodiments and referring to the figures in the appended drawings. As used in this application, access point refers to a general connection point in a data transmission network to which the terminal equipment may connect itself in order to set up an access to the data transmission network.
FIG. 2 shows the structure of an access network in accordance with the invention. The figure shows three alternative routes R 1 , R 2 and R 3 from terminal equipment TE to a host by way of an intermediary internet network and gateway exchange GW. According to the invention, one can hereby choose between several alternative routes, in the case shown in FIG. 2 there are three routes, of which at least one access at a time is chosen for use by the terminal equipment. The accesses connected to the terminal equipment may be e.g. Ethernet, IR and GSM data accesses. In the terminal equipment an APPL application is running, for the use of which the access is chosen. When required, the traffic between the terminal equipment and the host may be compressed and/or encrypted.
In the following, the invention will be described in greater detail in the light of a primary embodiment of the invention and referring to FIG. 3 , which is a flow chart of a primary embodiment of the method according to the invention. At point 30 in FIG. 3 at least one criterion is established for the choice of access. At point 31 the available accesses are monitored with the aid of their pre-established criteria according to the invention. This monitoring may be performed e.g. by monitoring each available access constantly or at certain intervals of time. At point 34 a check is made on whether the pre-established criteria have been met. There may be one criterion or more criteria at the same time, whereby in the case of several criteria the choice requires that all established criteria are met. Removal from use of a current access may be such a criterion which will trigger off an exchange of access. The check on criteria at point 34 may also be carried out by monitoring the quality of data transmission. After the condition 34 is fulfilled, a choice is made at point 36 of the access indicated by the criteria, and hereafter the traffic will be routed through this new access.
In a primary embodiment of the method according to the invention it is also possible to choose more than one access for connection at the same time between the terminal equipment and the host. FIG. 4 shows by way of example a network structure wherein data is transmitted along at least two different routes between terminal equipment TE and the host. In FIG. 4 a gateway exchange transmits to terminal equipment TE the data packages which it has received from the host both along route R 1 and along route R 2 . Gateway exchange GW may number the data packages before the transmission, as the marks indicate in FIG. 4 . Due to transmission errors, terminal equipment TE in the example shown in FIG. 4 receives through access R 1 numbered packages I,III,IV and through access R 2 packages I,II,III. By combining these packages received along different routes terminal equipment TE receives the entire transmitted series of packages. Owing to the numbering of the data packages, terminal equipment TE is able to screen away redundant packages, in the case shown in FIG. 4 second packages I and III, which are thus received both through access R 1 and through access R 2 . The numbering of packages also makes it possible to determine the characteristics of the different accesses by comparing the numbering of packages received through these different accesses. In FIG. 4 access R 3 is a standby access and this access point is monitored in accordance with the invention with the aid of the access choice criteria, as was described above in connection with the primary embodiment of the invention. Should terminal equipment TE in the case shown in FIG. 4 decide to change the access to access point R 3 , terminal equipment TE after its change of access point may inform the network what number the data package must have which is to be sent next. Gateway exchange GW need not necessarily send all data packages along each available route.
According to the functionality of the primary embodiment of the invention, the terminal equipment may first be connected to the host by an Ethernet access (R 1 ), whereby the data is routed through this access. When the user removes the Ethernet access card, a message of this is relayed to the terminal equipments router, which according to the invention will look for a new alternative route, on which the operation can be continued. Any data packages arriving for transmission while a new route is being sought are placed in a queue to wait, until a new route is found. The search for a new route may also be carried out beforehand while the connection in use is still working. When a new route is found, e.g. an IR access (R 2 ), the operation is continued through the IR access, until it is time for the IR access to be abolished. The router again receives information on the removal of the access and it will seek a new access to carry on the operation. When the user connects to a GSM data service, the router will route the data transmission by way of the GSM data access (R 3 ). In the routing example according to the invention described above, the transmission connection is essentially formed by a continuous network access, which may be momentarily disconnected only during the time when a new route is sought and connected for use.
FIG. 5 is a flow chart of a secondary embodiment of the method according to the invention. In the secondary embodiment of the invention, the traffic is divided between at least two accesses according to pre-established criteria. At point 50 at least one criterion is established for the choice of transmission capacity of the access. At point 51 a check is made of the available accesses with the aid of these pre-established criteria according to the invention. This check may be carried out e.g. by monitoring each available access constantly or at certain intervals. At point 54 a check is made of whether the situation of the accesses has changed from the viewpoint of the criteria. A criterion triggering off a new division of the traffic may be e.g. such a change of the transmission capacity available in the access that it exceeds or falls short of a certain value or several different values. The check of criteria at point 54 may also be carried out by monitoring the quality of the data transmission. After the condition 54 is fulfilled, the traffic is divided at point 56 between the accesses in the proportion indicated by the result of the criteria check, e.g. so that a certain part of the traffic is relayed through one access and the remaining traffic through another access.
The primary and secondary embodiment of the invention which were described above can also be combined, whereby a choice of at least two accesses at a time is performed in the router in accordance with the primary embodiment of the invention, while the division of traffic between the chosen accesses is performed in accordance with the secondary embodiment of the invention. Hereby the criteria for the choice of access and the criteria for division of the traffic between accesses may be criteria which are separate from one another.
As criteria mentioned above one may establish e.g. the costs of data transmission, so that a certain access is chosen, e.g. a GPRS access, or as much as possible of the traffic is always transmitted in this access when no such access is available where the operation would be cheaper, such as e.g. Ethernet. Other criteria may be e.g. the transmission capacity, transmission delays, data security or transmission errors, whereby the criterion is fulfilled e.g. when some other access is better than the access in use as regards the established criterion or it is found that the access in use is poor according to one criterion. Hereby such an access may be chosen as the new access which fulfils the second criterion, or the relaying of traffic can be moved more to the access fulfilling the second criterion. The transmission capacity criterion can be used for choosing and putting into use a new access point e.g. when a new application starts up and sets up a connection requiring more transmission capacity. Several criteria of choice may be established at the same time, e.g. any combination of the criteria of choice mentioned above. The criteria of choice are preferably established so that the traffic can be directed to the new access before the transmission capacity of the old access is removed.
In a third embodiment of the invention, at least some of the access choice criteria are learning criteria, which are established in accordance with the user's repeating activity. Hereby the criteria of choice are e.g. the time and/or the place, where the terminal equipment is connected to the first access point. If the terminal equipment moves repeatedly along the same geographical route, it is possible to foresee the need to change access point and to connect the new access point in advance to operate with the terminal equipment. Hereby e.g. in a situation of access change the terminal equipment is in connection through at least two access points at the same time, whereupon the traffic through the first access can be stopped. In other respects the functionality of the third embodiment of the method according to the invention is similar to the functionality of any embodiment described earlier.
The applications to use make demands on the access to use, e.g. as regards the transmission capacity and/or transmission errors. Hereby the criteria may be changed according to the requirements of the applications so that they suit the existing situation. On the other hand, the characteristics of the chosen access point may provide the applications with possibilities e.g. for starting new functions. The functionality according to the invention can be implemented fully transparently from the viewpoint of the application used and from the user's viewpoint or also in such a way that the chosen access point/points and the possibilities provided by the chosen access points are reported to the application to be used and/or to the user, so that the application or the user may when he so desires utilise the new possibilities provided by the access/accesses and/or adapt his operation so that it suits the access. The demands made by the application on the data transmission can be determined from the protocol used by the application or from the QoS (Quality of Service) parameters established by the application, which define certain demands made on the data transmission, or by providing the application with an interface, through which the application may establish any routing criterion presented herein. By reporting to the application the transmission capacity information of the access in use it is possible to perform such a gradation of the various functions of the application that the transmission capacity in use at each time is sufficient to ensure a normal operation of the application. E.g. transmission of e-mail from the application may be delayed until there is sufficient transmission capacity available for transmitting both the other traffic and e-mail messages. When desired, the application may also be given reports on the characteristics of alternative available routes, e.g. on the transmission capacity, so that the application is aware of any available additional transmission capacity, which its functionality may require later.
In a first alternative embodiment of the invention, the router is located in terminal equipment TE, which may move from one place to another and connect to the data transmission network when required. For terminal equipment TE to connect to access points of the data transmission network no new additional functions are needed at the access points or in the access protocols compared with the state of the art.
FIG. 6 shows the structure of terminal equipment TE according to the invention at protocol level. When the Internet network relays data between the host and terminal equipment TE, the terminal equipment uses TCP/IP protocols in the manner shown by the figure. The router joins the other functionality by way of the IP protocol. The user's data packages may be capsulated between the router of terminal equipment TE and gateway exchange GW using some state-of-the-art method, such as e.g. Mobile IP.
In a second alternative embodiment of the invention, the router is located both in terminal equipment TE and in gateway exchange GW. Both these routers independently implement the functionality of the invention in accordance with some embodiment described in the foregoing.
In a third alternative embodiment of the invention, the router is located in gateway exchange GW, which routes the data transmission to the terminal equipment at least by way of one access according to criteria established in advance.
The functionality according to the invention may of course be used also if the data transmission network does not include any intermediary network and gateway exchange, but the terminal equipment is connected directly to the host through at least two access points.
The drawings and the description relating to them are only intended to illustrate the inventive idea. As regards its details the functionality according to the invention may vary within the scope of the claims. The invention is especially suitable for use in transmission in the form of packages, e.g. in connection with a GPRS network, but also in data transmission of some other kind. The invention is not limited to use only in connection with the access points described above. | A problem with known data transmission networks is that the connection of the terminal equipment to the data transmission network is not flexible. The user must himself actively perform the choice and connection of access as well as its registration with the network nodal point. The invention concerns a method and an arrangement for routing a data transmission connection between terminal equipment (TE) and a host over a data transmission network, which network includes at least two access points (R 1 , R 2 , R 3 ) for connecting the terminal equipment to the data transmission network. The method is characterized in that at least one criterion is established for the choice of access point, the access points are estimated according to said criteria, at least one access point meeting the criteria is chosen, and the data transmission traffic is connected through the chosen at least one access point. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a division of U.S. application Ser. No. 10/431,172, filed on May 6, 2003 and issued as U.S. Pat. No. 6,911,370, which claims priority to U.S. Provisional Patent Application No. 60/383,470, filed on May 24, 2002, which disclosures are incorporated by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to integrated circuit nonvolatile memories, and in particular to flash memories. Flash memories are electrically erasable nonvolatile memories in which groups of cells can be erased in a single operation.
Numerous types of integrated circuit memory are now well known, as are processes for manufacturing them. One particular type of integrated circuit memory is nonvolatile memory. Nonvolatile memory is referred to as such because it does not lose the information stored in the memory when power is removed from the memory. Nonvolatile memory has many applications in products where the supply of electricity is interruptable. For example, one well known product employing flash memory is PCMCIA or PC cards. PC cards are small credit card-sized packages that contain nonvolatile memory within which a computer program or other information is stored. Such devices allow the user to connect and disconnect the memory card from a computer or other electronic apparatus, without losing the program stored within the memory card.
Nonvolatile memory devices include read only memories (ROM), programmable read only memories (PROM), electrically erasable read only memories (EEPROM), as well as other types. Within the field of electrically erasable programmable memories, a certain class of devices is known as flash memory, or flash EEPROMs. Such memories are selectively programmable and erasable, typically with groups of cells being erasable in a single operation.
In conventional flash memories, each memory cell is formed from a transistor having a source, drain, control gate and floating gate. The floating gate is formed between the control gate and the substrate. The presence, or absence, of charge trapped on the floating gate can be used to indicate the contents of the memory cell. Charge trapped on the floating gate changes the threshold voltage of the transistor, enabling detection of its binary condition.
In most flash memories, charge is placed on, or removed from, the floating gate by operating the memory at conditions outside its normal operating conditions for reading its contents. For example, by adjusting the relative potentials between the gate and the source, drain or channel regions, charge, in the form of electrons, can be caused to be injected onto the floating gate, or removed from the floating gate.
BRIEF SUMMARY OF THE INVENTION
According to one embodiment of the present invention, a non-volatile memory device includes a substrate having a first active region and a second active region. A first floating gate is provided over the first active region and having an edge, the first floating gate being made of a conductive material. A first spacer is connected to the edge of the first floating gate and being made of the same conductive material as that of the first floating gate. A control gate is provided proximate to the floating gate.
In another embodiment, a flash memory device includes a substrate having a first active region and a second active region. A field trench oxide separates the first and second active regions. A floating gate is provided over the first active region and having an edge, the first floating gate being made of polysilicon. A spacer is coupled to the edge of the floating gate and being made of polysilicon, the spacer having a slope less than about 60 degrees. A control gate overlies the floating gate. A metal layer is provided over the control gate, wherein the spacer reduces formation of a void in the metal layer.
In another embodiment, a method of fabricating a non-volatile memory device includes forming a polysilicon floating gate over a substrate, the floating gate having an edge; forming a polysilicon spacer joined to the edge of the floating gate, the spacer having a sloping edge having a slope less than 60 degrees; and forming a polysilicon control gate over the floating gate and the spacer.
In another embodiment, a non-volatile memory device includes a substrate having a first active region and a second active region; an isolation structure separating the first and second active regions; a first floating gate provided over the first active region and having a first edge, the first floating gate being made of a conductive material; a first spacer connected to the first edge of the first floating gate and having a first sloping edge, the first spacer being of a conductive material and overlying the isolation structure; and a control gate provided proximate to the floating gate. The first sloping edge of the first spacer forms an angle of less than 65 degrees to facilitate deposition of material over the first spacer and the isolation structure. The device further includes a second floating gate provided over the second active region and having a second edge, the second floating gate being of the same conductive material as the first floating gate; a second spacer connected to the second edge of the second floating gate and having a second sloping edge, the second spacer being of a conductive material and overlying the isolation structure and electrically isolation from the first spacer; a metal layer overlying the first and second floating gates and the isolation structure, wherein each of the first and second sloping edges forms an angle of less than 65 degrees, so that a portion of the metal layer overlying the isolation structure is substantially free of a void. The metal layer includes tungsten or aluminum.
In yet another embodiment, a method for fabricating a non-volatile memory device includes forming a first polysilicon layer over an isolation structure and first and second regions of a substrate, the first and second regions being defined by the isolation structure; forming a dielectric layer overlying the first polysilicon layer; etching the first polysilicon layer and the dielectric layer to expose a portion of the isolation structure, the etching step defining a first edge associated with the first region and a second edge associated with the second region; forming a second polysilicon layer over the exposed portion of the isolation structure, the second polysilicon layer contacting the first and second edges; etching the second polysilicon layer to form a first spacer joined to the first edge and a second spacer joined to the second edge; forming an interpoly dielectric layer overlying the first and second spacers and the first polysilicon layer; forming a third polysilicon layer overlying the interpoly dielectric layer; and forming a metal layer over lying the third polysilicon layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a schematic top view of a flash memory device.
FIGS. 2A-2E illustrate a conventional method of fabricating a control gate and a tungsten silicide thereon.
FIGS. 3A-3I illustrate a method of fabricating a control gate and a tungsten silicide without a void or seam therein according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a schematic top view of a flash memory device 100 . The device 100 includes a plurality of active regions 102 and 104 separated by a field trench oxide region 106 . A plurality of floating gates 108 is provided overlying the active regions 102 and 104 . The floating gates are generally formed using polysilicon and commonly referred to as a “poly 1 layer” or “P1.” The floating gates generally extend over the field trench oxide region 106 to define a P1-to-P1 spacing 110 that is less than the width of the field trench oxide region 106 . A plurality of control gates 112 is provided over the floating gates. The control gates are generally formed using polysilicon and also referred to as a “poly 2 layer” or “P2.” A drain region 114 is provided at one side of the floating gate. A source region 116 is provided at the other side of the floating gate.
FIGS. 2A-2E illustrate a conventional process flow of forming a metal layer, e.g., a tungsten silicide layer, overlying a control gate. A void or seam may be formed within the metal layer due to step coverage problem, described below, which is undesirable since the void would increase the sheet resistance of the metal layer.
A field trench oxide 202 is formed to electrically isolate adjacent active regions ( FIG. 2A ). A first polysilicon layer 204 having a thickness of about 500-1,000 Å is deposited on the trench oxide 202 . The first polysilicon layer 204 is etched to define a floating gate ( FIG. 2B . Along with the unwanted portions of the first polysilicon layer, a portion of the trench oxide 202 is etched to form a groove 206 . The groove 206 defines edges 208 and 210 . The unetched portion of the first polysilicon layer 204 defines the floating gate. An interpoly dielectric layer 212 is then formed over the first polysilicon layer and the substrate ( FIG. 2C ). The layer 212 is often called the interpoly dielectric film since it is sandwiched between the first polysilicon layer and another polysilicon layer which defines the control gate for each cell, as will be explained later.
Referring to FIG. 2D , after the formation of the interpoly dielectric layer 212 , a second polysilicon layer 214 having a thickness of about 1000-2000 Å is deposited over the dielectric layer and the substrate using one of many techniques. Due to the conformal nature of the polysilicon deposition, the second polysilicon layer is unable to fill the groove 206 . Accordingly, a P2 groove 216 having edges 218 and 220 is formed after the deposition of the second polysilicon layer. The edges 218 and 220 are relatively high because each successive layer formed over the groove 206 adds to the height.
A metal layer 222 , e.g., a tungsten silicide (Wsi), is deposited over the second polysilicon layer ( FIG. 2E ). As a result of the relatively high edges 218 and 220 , a void or seam 224 may be formed within the tungsten silicide provided between the edges 218 and 220 . The void 224 decreases the conductivity of the tungsten silicide that is undesirable since it may reduce the operational speed of the device.
FIGS. 3A-3I illustrate a process flow of forming a metal layer, e.g., a tungsten silicide layer, overlying a control gate according to one embodiment of the present invention. The process flow described reduces formation of a void or seam within the metal layer and improves the coupling coefficient of the floating gate.
A field trench oxide 302 is formed on a substrate 300 to electrically isolate adjacent active regions ( FIG. 3A ). Although the figure shows a single trench oxide, numerous trench oxides are formed simultaneously on the substrate. The substrate is a silicon substrate, preferably of 8-10 ohm centimeter resistivity, and of crystal orientation <100>. A first polysilicon layer 304 having a thickness of about 500-1,000 Å is deposited on the trench oxide 302 . Generally, the first polysilicon layer is deposited using a low pressure chemical vapor deposition (“LPCVD”) process and is lightly doped. The methods used to dope the first polysilicon include diffusion doping, in-situ doping, and ion implantation doping techniques. The polysilicon layer is doped with n-type dopants to a concentration level of about 1×10 19 dopants per cubic centimeter.
A dielectric layer 306 is formed over the first polysilicon layer 304 ( FIG. 3B ). The dielectric layer 306 is relatively thin, e.g., about 500 Å or less. The dielectric layer may be PSG or other suitable materials.
Thereafter, the dielectric layer 306 and the first polysilicon layer 304 are etched, preferably in a single etch step ( FIG. 3C ). The etch step includes forming a masking layer (not shown) over the dielectric layer and the first polysilicon layer, patterning the mask layer to expose an unwanted portion 308 of the dielectric layer that is overlying the trench oxide 302 . The exposed portion 308 of the dielectric layer 306 and a portion 310 of the first polysilicon layer underlying the exposed dielectric layer are removed using a dry etch method such as a reactive ion etching process (“RIE”) using a plasma ignited from a gas mixture of HBr and O 2 or HBr, Cl 2 and O 2 .
Along with the unwanted portions 308 and 310 , a portion 312 of the trench oxide 302 is etched as well in an over etch since a precise etch control is difficult ( FIG. 3C ). Generally, a slight over etch is desired to ensure electrical isolation between two portions 314 and 316 of the polysilicon layer 304 defined by the etch step. These portions of the polysilicon layer 304 define floating gates for the adjacent flash memory transistors or cells. A groove 318 is formed on the trench oxide 302 as a result of the over etch. The groove and the polysilicon portions 314 and 316 together define edges 320 and 322 that are substantially vertical or have relatively high slopes since the etch step used to removed the unwanted portions generally is an anisotropic etch.
Referring to FIG. 3D , a sacrificial or second polysilicon layer 324 is deposited over the dielectric layer 306 , the groove 318 , and edges 320 and 322 to form polysilicon spacers (see FIG. 3E ). The polysilicon layer 324 is deposited using a low pressure chemical vapor deposition (“LPCVD”) process. Due to the conformal nature of the polysilicon deposition, portions 326 and 328 of the sacrificial layer 324 are contacting the edges of the first polysilicon layer 306 . The sacrificial layer is lightly doped. The methods used to dope the first polysilicon include diffusion doping, in-situ doping, and ion implantation doping techniques. The sacrificial polysilicon layer is doped with n-type dopants to a concentration level of about 1×10 19 dopants per cubic centimeter. The doping level of the layer 324 is substantially similar to that of the first polysilicon layer 304 since the layer 324 will be used to form spacers for the floating gates. Alternatively, the different doping levels may be used for the sacrificial layer. In one implementation, the layer 324 has a thickness of about 300-1,000 Å. Alternatively, the layer 324 may be greater or lesser in thickness according the thickness of spacers desired.
Polysilicon or poly spacers 330 and 332 are formed by blanketly etching away the sacrificial polysilicon layer 324 ( FIG. 3E ). The poly spacers 330 and 332 are electrically
coupled to the floating gates 314 and 316 , respectively. A separation 334 is provided between the two poly spacers 330 and 332 , so that the electrical isolation of the floating gates 314 and 316 is maintained. The spacers 330 and 332 have sloping edges 336 and 338 that is substantially less than 90 degrees. In one implementation, the slopes of the edges 336 and 338 are about 70 degrees or less, 65 degrees or less, 60 degrees or less, 50 degrees or less, 40 degrees or less, or 30 degrees or less. The etch step used to remove the sacrificial polysilicon layer may be controlled to obtain different slopes for the poly spacers, as desired for different applications. For example, the gas composition and/or bias power (when RIE is used) can be adjusted for control the slope of the spacers. The angle of the sloping edge is defined by a plane 333 that is substantially parallel to the upper surface of the substrate 300 and a line 331 that is tangent to the sloping edge 336 or 338 , i.e., an angle 335 .
Thereafter, the dielectric layer 308 is removed ( FIG. 3F ). An interpoly dielectric layer 340 is then formed over the first polysilicon layer 304 , the spacers 330 and 332 , and the trench oxide 302 ( FIG. 3G ). The layer 340 is often called the interpoly dielectric film since it is sandwiched between the first polysilicon layer and another polysilicon layer which defines the control gate for each cell, as will be explained later. The interpoly dielectric layer can be a silicon oxide or an ONO layer having a thickness of about 150-400 Å, where the ONO layer has oxide, nitride, and oxide layers stacked in sequence. As a result of the underlying spacers, the ONO layer 340 is also provided with sloping edges 342 and 344 since the layer 340 are deposited conformally. In implementation, the slopes of the edges 342 and 344 are about 70 degrees or less, 60 degrees or less, 50 degrees or less, 40 degrees or less, or 30 degrees or less.
Referring to FIG. 3H , a third polysilicon layer 346 having a thickness of about 700-2000 Å, generally about 1000 Å, is deposited over the dielectric layer to form a control gate. Generally, the third polysilicon layer is deposited using a LPCVD process and is heavily doped in contrast to the first polysilicon layer. The methods used to dope the third polysilicon layer include diffusion doping, in-situ doping, and ion implantation doping techniques. In one embodiment, the polysilicon layer 346 is doped with n-type dopants to a concentration level of about 1×10 21 dopants per cubic centimeter or to another concentration level suitable for a control gate. As a result of the sloping ONO layer 340 and the spacers 330 and 332 , the polysilicon layer 346 is provided with smoother surface than otherwise possible. For example, a groove 348 provided on the polysilicon layer 346 between the spacers 330 and 332 has substantially less depth than the groove 216 ( FIG. 2D ) formed under the conventional method.
A metal layer 350 , e.g., a tungsten silicide (Wsi), is deposited over the third polysilicon layer ( FIG. 2E ). The metal layer is free of a void or seam unlike in the conventional method due to the relatively smooth surface of third polysilicon layer, thereby providing a higher conductivity for the metal layer.
While the above is a full description of the specific embodiments, various modifications, alternative constructions and equivalents may be used. For example, specific dimensions discussed above are for the specific embodiments. These dimensions may depend on the particular application. Therefore, the above description and illustrations should not be taken as limiting the scope of the present invention which is defined by the appended claims. | A non-volatile memory device includes a substrate having a first active region and a second active region. A first floating gate is provided over the first active region and having an edge, the first floating gate being made of a conductive material. A first spacer is connected to the edge of the first floating gate and being made of the same conductive material as that of the first floating gate. A control gate is provided proximate to the floating gate. | 7 |
TECHNICAL FIELD
The present disclosure relates generally to the design of a bucket to be used with a machine and, more particularly, to a bucket with pockets that engage rollers near the tips of fork tines.
BACKGROUND
Machines, such as fork lifts, wheel loaders, and backhoes, are frequently used in work environments to collect and transport loads. When operating these machines, it is often desirable to utilize auxiliary work implements or equipment with the machine, such as buckets, forks, and grapples, each of which assists the machine in performing work functions. When a machine uses multiple work implements, changing one implement out for another can be a time-consuming and labor-intensive process.
For example, in a forestry mill yard, a fork is often attached to a machine to collect and transport poles around the mill yard. The fork is able to move under the poles and support the weight of the poles when moving the poles in the mill yard. It can also be desirable to attach a bucket to the machine to clean up wood chips and other debris created during the milling process. It is inefficient and labor intensive for the mill yard to remove the fork and attach a bucket when collecting wood chips and debris is desired. After the wood chips and debris are collected, the bucket needs to be detached from the machine and the fork reattached, creating more inefficiency. The mill yard would save time and labor if the fork would not have to be removed from the machine every time the mill yard needed to use the bucket and then reattached after there was no longer a need for the bucket.
U.S. Pat. No. 6,168,369 to Bright discloses a system for attaching a bucket to a fork and transporting it. In this design, the bucket is not used when attached to the fork. The bucket is only attached to the fork so it can be transported between two places. An operator is unable to actually use the bucket when it is attached to the fork. Ultimately, to use the bucket, the operator still needs to disconnect the fork from the machine and connect the bucket. The fork and bucket cannot both be attached to the machine.
The apparatus of the present disclosure alleviates one or more of the deficiencies of the prior art.
SUMMARY OF THE INVENTION
One aspect of the present disclosure is directed to a bucket having a pair of opposing first and second side members; a collecting member extending between the first and second side members; the collecting member and the first and second side members defining a cavity; and an engagement portion having an engagement surface and a pocket.
Another aspect of the present disclosure is directed to a bucket having a pair of opposing first and second side members; a collecting member extending between the first and second side members; the collecting member and the first and second side members defining a cavity; an engagement surface; and a recess.
Another aspect of the present disclosure is directed to a bucket having means for collecting material; means for positioning the bucket relative to a tine; and means for receiving an elevated portion of the tine.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a machine with an exemplary embodiment of a fork;
FIG. 2 illustrates a machine with an exemplary embodiment of a fork and an exemplary embodiment of a bucket;
FIG. 3 is an isometric view of an exemplary embodiment of a fork;
FIG. 4 is a side perspective of an exemplary embodiment of a tine;
FIG. 5 is a front perspective of an exemplary embodiment of a tine;
FIG. 6 illustrates an exemplary embodiment of a tine, with a roller and a pin disassembled from the tine;
FIG. 7 is a front perspective of an exemplary embodiment of a bucket;
FIG. 8 is a rear perspective of an exemplary embodiment of a bucket;
FIG. 9 is an isometric view of an exemplary embodiment of a fork in use with a bucket; and
FIG. 10 is a sectional view along an engagement portion of a bucket, illustrating an exemplary embodiment of a tine engaged to a bucket.
DETAILED DESCRIPTION
Referring now to FIG. 1 , a machine 100 is shown with an exemplary embodiment of a fork 10 . Machine 100 may be a fork lift, wheel loader, backhoe, or one of a variety of other machines that may make use of a fork 10 . Fork 10 may be removably connected to machine 100 , as is well known by a person of ordinary skill in the art.
According to one exemplary embodiment, fork 10 includes at least one tine 20 and a clamp 15 . Tine 20 is designed to support a load, and to allow machine 100 to carry the load from one location to another. Clamp 15 assists in retaining and holding the load being transported on tine 20 . Near the end of tine 20 , there is a roller 30 . Roller 30 is free to rotate and helps prevent damage to the load when the load is collected by machine 100 . Instead of a sharp tip impacting the load and potentially causing gouging, scarring, and other damage, roller 30 impacts the load and directs the load onto tine 20 . Machine 100 generally utilizes a hydraulic system to raise and lower fork 10 as desired by the operator.
Referring now to FIG. 2 , machine 100 is shown with the exemplary embodiment of fork 10 , but now with an exemplary embodiment of a bucket 60 attached to fork 10 . The design of the present disclosure allows easy attachment of bucket 60 to fork 10 , reducing time and labor costs associated with disconnecting a fork from a machine, connecting the bucket to the machine, removing the bucket from the machine, and then connecting the fork back to the machine. The present disclosure allows integration of bucket 60 with fork 10 .
FIG. 3 shows an exemplary embodiment of fork 10 in isometric view. Fork 10 has two tines 20 . Near the end of each tine 20 is a roller 30 . While fork 10 generally contains two tines 20 , and is illustrated as having two tines 20 in FIG. 3 , the present disclosure anticipates that a fork could be constructed of one tine or multiple tines. Nothing herein is intended to limit a fork to having two tines.
Fork 10 also includes a clamp 15 , which assists in retaining and holding material onto tines 20 . Clamp 15 can be lowered by the operator when a load is positioned on tines 20 of fork 10 to hold the load in place while the machine is in movement. Clamp 15 will typically be lowered with a hydraulic system. Fork 10 need not include clamp 15 , and a person of ordinary skill in the art would recognize that other work implements could be combined with a fork. These other combinations are intended to fall within the scope of the present disclosure.
Referring now to FIG. 4 , a side view of an exemplary embodiment of tine 20 is shown. Tine 20 includes roller 30 and a base member 50 . Base member 50 includes a first side wall 52 , a second side wall 54 , a top surface 56 , and a distal end 58 . Base member 50 may include a bottom surface, not illustrated, and may be solid or hollow.
In the exemplary embodiment shown in FIG. 4 , roller 30 is located adjacent to top surface 56 and distal end 58 . A part of roller 30 is elevated above base member 50 and top surface 56 . The elevated part of roller 30 serves multiple functions, as will be discussed. A part of roller 30 also extends out in front of first side wall 52 , second side wall 54 , and distal end 58 . By having a part of roller 30 extend out in front of and above base member 50 , the possibility of damage to the load during collection is minimized. This is because as the tine 20 approaches the load to be carried, the first part of tine 20 to come into contact with the load is roller 30 , instead of the sharp protrusion from first side wall 52 , second side wall 54 , or distal end 58 , which could damage the load. Roller 30 comes into contact with the load without a sharp point, and is able to direct the load onto the top surface 56 of tine 20 .
In FIG. 5 , the exemplary embodiment of tine 20 described with respect to FIG. 4 is shown in a front perspective view. Roller 30 is mounted on a pin 40 . Pin 40 is connected to base member 50 proximal to distal end 58 between first side wall 52 and second side wall 54 . Pin 40 is held into position in first side wall 52 by a first cap 252 and in second side wall 54 by a second cap 254 . Pin 40 does not extend beyond the outer boundary of first side wall 52 or second side wall 54 . In fact, the length of pin 40 is less than or equal to the width of base member 50 . If pin 40 were to extend beyond the outer boundary of first side wall 52 or second side wall 54 , pin 40 could catch on material during the operation of machine 100 and become damaged. This is prevented by making the length of pin 40 reside within the width of base member 50 .
In an exemplary embodiment, roller 30 is positioned on pin 40 such that roller 30 is centered with respect to the width of base member 50 . Roller 30 may also be fixed on pin 40 and restrained from shifting along the length of pin 40 . By centering roller 30 and fixing its position, roller 30 is more effective in preventing damage to the load. Allowing roller 30 to float along pin 40 could result in more damage to roller 30 as it comes into contact with first side wall 52 and second side wall 54 , which could shorten the life of roller 30 and require it to be replaced more frequently. It is also desirable to center roller 30 and fix its position to enable tine 20 to properly mate with bucket 60 , as will be described.
Referring now to FIG. 6 , an exemplary embodiment of tine 20 with roller 30 and pin 40 disassembled from tine 20 is shown. Pin 40 and roller 30 are removable from tine 20 , so that each can be replaced should either become damaged during operation of machine 100 . Pin 40 is not connected to base member 50 by welding, so that roller 30 and pin 40 may be more easily replaced or repaired.
An axial bore is provided in first side wall 52 creating first hole 152 and second side wall 54 creating second hole 154 . Pin 40 mounts in first hole 152 and second hole 154 to mate with base member 50 . First cap 252 is then placed into first hole 152 and second cap 254 is placed into second hole 154 . The caps are welded to first side wall 52 and second side wall 54 to hold pin 40 in place. To remove roller 30 and pin 40 , one cap may be removed to allow access to pin 40 . Pin 40 is then removed, freeing roller 30 . For ease of removal of roller 30 and pin 40 , first cap 252 and second cap 254 may also contain an axial hole, not illustrated, so that when either first cap 252 or second cap 254 is removed, an operator may slide a guide pin, not illustrated, through the axial hole of the remaining first cap 252 or second cap 254 , forcing pin 40 out of engagement with base member 50 , and freeing roller 30 .
In an alternative embodiment, not illustrated, first hole 152 and second hole 154 could be threaded and pin 40 then held in place by screws or other threaded fasteners inserted into first hole 152 and second hole 154 .
FIG. 7 shows a front view of an exemplary embodiment of bucket 60 . Bucket 60 includes a first side member 62 , a second side member 64 , and a collecting member 66 . Together first side member 62 , second side member 64 , and collecting member 66 form a cavity 68 . Bucket 60 is designed to collect and hold material in cavity 68 . Bucket 60 may also contain screens 86 , which are positioned on bucket 60 to allow the operator to see in front of bucket 60 during collection.
Bucket 60 also includes an engagement portion 70 , which includes an engagement surface 72 and a pocket 80 . While bucket 60 is shown with two engagement portions 70 , and each engagement portion 70 is shown with two pockets 80 , the present disclosure anticipates that a bucket could be constructed with one engagement portion or multiple engagement portions. Additionally, each engagement portion could be constructed with one pocket or multiple pockets. Nothing herein is intended to limit a bucket to having two engagement portions, nor is it intended to limit each engagement portion to having two pockets.
Engagement surface 72 is a segment of engagement portion 70 , and is the part of bucket 60 that tine 20 will engage with, mate with, or seat on. In FIG. 7 , engagement portion 70 extends into cavity 68 . Thus, engagement surface 72 is elevated above the lowest point of bucket 60 . This allows bucket 60 to be lowered all the way to the ground without interference by tines 20 . In other embodiments, the engagement portion may not extend into the cavity of the bucket, or any portion of the bucket at all. For example, the engagement surface may be along the base of the bucket. In that case, only the pocket would extend into the body of the bucket. Depending on the thickness of the base of the bucket, the pocket may or many not extend into the cavity.
Pocket 80 is a region designed to mate with or engage with an elevated portion of tine 60 which, in this exemplary embodiment, is roller 30 . In the exemplary embodiment shown, pocket 80 is a physical receptacle, box, or recess that helps to hold roller 30 in place. An operator is able to insert tine 20 into engagement portion 70 , and receives auditory, visual, and/or tactile feedback when roller 30 engages in pocket 80 indicating that bucket 60 is properly seated on tine 20 . In any alternative embodiment, pocket 80 may define an opening, not illustrated, such that roller 30 would enter a void, but roller 30 would be held in place by the edges around the opening.
Pocket 80 serves an additional function. By accepting roller 30 , engagement surface 72 is able to sit flat on top surface 56 of tine 20 . This allows the weight of bucket 60 to be more evenly distributed across tine 20 . The length of engagement surface 72 in contact with top surface 56 may vary. Ideally, the length of engagement surface 72 will be at least fifty percent of the overall length of bucket 60 , and the length of top surface 56 will be at least fifty percent of the overall length of base member 50 .
In the exemplary embodiment, bucket 60 contains multiple pockets 80 , so that tines 20 of different lengths may be used with bucket 60 . Thus, an owner of several forks with different time 20 lengths only needs a single bucket 60 . This saves the owner the cost of an additional bucket, as well as the space needed to store an additional bucket.
FIG. 8 shows a rear view of the exemplary embodiment of bucket 60 described with respect to FIG. 7 . In the embodiment shown, the engagement portions 70 consist of two channels spaced apart and fitted to receive two tines 20 . Screens 86 are shown so that the machine's operator can see in front of the bucket as machine 100 is moving. Bucket 60 also has a connection 88 , so that it can be fixed to machine 100 , by fixing bucket 60 to fork 10 through the use of a retention pin, not illustrated, that fits into connection 88 and corresponding receptacles located on either machine 100 or fork 10 . Other retention mechanisms may also be used.
FIG. 9 shows an isometric view of the exemplary embodiment of bucket 60 , as described in FIGS. 7 and 8 , engaged to fork 10 . Bucket 60 is engaged to fork 10 by slipping tines 20 into engagement portions 70 until rollers 30 engage pockets 80 . When rollers 30 seat in pockets 80 , engagement surface 72 comes into contact with top surface 56 of base member 50 , thereby distributing the weight of bucket 60 along base member 50 . Dashed line A represents the plane that the sectional view depicted in FIG. 10 is cut along.
FIG. 10 shows a sectional view along tine 20 and engagement portion 70 of an exemplary embodiment of tine 20 engaged to bucket 60 . Pockets 80 extend above engagement surface 72 . Roller 30 is engaged in one of pockets 80 . Because roller 30 is received within in pocket 80 , engagement surface 72 is able to rest on base member 50 and, in particular, top surface 56 , distributing the weight of bucket 60 along base member 50 . Pockets 80 , located along engagement portion 70 , allow bucket 60 to be connected to tines 20 of different lengths. As a result, bucket 60 can be connected to machines with different tine lengths.
INDUSTRIAL APPLICABILITY
Tine 20 and bucket 60 of the present disclosure may be applicable to any machine using fork 10 , including a fork lift, wheel loader, and backhoe. Tine 20 is connected to machine 100 and designed to collect and carry a load. Tine 20 is also designed for connection to bucket 60 , so that fork 10 does not need to be disconnected from machine 100 for machine 100 to use bucket 60 . Roller 30 on tine 20 is useful in minimizing damage to the load being collected by the machine and to engage tine 20 to bucket 60 .
More specifically, in the forestry setting, machine 100 will collect a pole or multiple poles with tine 20 , then carry the poles to a destination with tine 20 supporting the weight of the poles. Roller 30 helps to prevent the poles from being gouged and damaged by tine 20 when machine 100 is collecting poles. Without roller 30 , the tip of tine 20 is more likely to gouge and damage the pole. With roller 30 , however, as machine 100 moves forward, the pole impacts roller 30 and is lifted onto tine 20 with minimal damage.
Should roller 30 or pin 40 become damaged, either may be replaced. According to one exemplary embodiment, pin 40 is not welded onto tine 20 , minimizing the amount of time and labor needed to replace a damaged roller 30 or pin 40 .
Tine 20 of the present disclosure also allows easy attachment of machine 100 to bucket 60 without having to disconnect tine 20 from machine 100 . The operator saves time and labor costs by avoiding the need to disconnect tine 20 from machine 100 and then reattaching tine 20 after using bucket 60 . Bucket 60 attaches to tine 20 by having tine 20 engage with engagement portion 70 , such that roller 30 fits into pocket 80 . When roller 30 fits into pocket 80 , bucket 60 rests on top surface 56 and base member 50 of tine 20 allowing the weight of bucket 60 to be distributed over the length of tine 20 .
Roller 30 also engages bucket 60 , minimizing movement of bucket 60 relative to tine 20 . Again, the operator saves time and labor costs through the ease of attaching bucket 60 to tine 20 , sliding tine 20 into engagement portion 70 until roller 30 sets into pocket 80 , and receiving positive feedback that engagement has occurred. This method avoids the complexity of positioning bucket 60 onto tine 20 and then fixing bucket 60 to either tine 20 or machine 100 .
In the forestry setting, bucket 60 is attached to tine 20 to allow machine 100 to collect chips and debris formed during milling operations. While bucket 60 is an important piece of equipment, it is only used for a limited time. So the ability to easily attach and remove bucket 60 is beneficial, and accomplished by slipping bucket 60 onto tine 20 until roller 30 seats in pocket 80 . Connection 88 may also be used with a retention pin to lock bucket 60 to machine 100 . When machine 100 is finished using bucket 60 , bucket 60 can be easily removed from tine 20 by disconnecting the retention pin fixing connection 88 to machine 100 , then angling tine 20 slightly downward, causing roller 30 to disengage from pocket 80 , and using machine 100 to pull tine 20 out of engagement portion 70 .
Additionally, bucket 60 has multiple pockets 80 along the engagement portion 70 to allow bucket 60 to be used with different tines 20 . For example, a first machine 100 is equipped with a tine 20 of a first length. A second machine 100 is equipped with a tine 20 of a second length. Ordinarily, each machine 100 would have a separate bucket designed for its specific tine 20 length. However, bucket 60 can be used with both first and second machines 100 . Pockets 80 are spaced apart so that both tine 20 of the first length and tine 20 of the second length will engage with bucket 60 . This saves the cost of having to purchase a separate bucket for each machine in a fleet. The present disclosure also contemplates buckets 60 with more than two pockets 80 along engagement portion 70 , such that bucket 60 can be used with more than two tines 20 of different lengths.
It should also be appreciated that tine 20 of the present disclosure will frequently be combined with clamp 15 or other means of retention, to assist with the retention of the load it is transporting, as is illustrated in FIGS. 1 , 2 , 3 , and 9 . For example, in the mill yard, clamp 15 would retain the poles that machine 100 is transporting from an initial point to a destination. Clamp 15 is not the only type of optional work implement that could be combined with fork 10 . Those skilled in the art will recognize other work implements that may be combined with fork 10 , all of which fall under the scope of the present disclosure.
A person of ordinary skill in the art will also recognize that tine 20 and bucket 60 may be manufactured of a hard, durable metal that will not be easily damaged in a work environment. Such materials are well known and any can be used to form tine 20 and bucket 60 . The use of these materials, such as steel and iron, will prolong the life of tine 20 and bucket 60 .
It will be apparent to those skilled in the art that various modifications and variations can be made to tine 20 of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the device disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalent. | Machines are often used to collect and transport materials in a work environment. One of the more common methods of collecting and transporting materials is with a fork having tines. Another common instrument attached to a machine for collecting and transporting materials is a bucket. The present disclosure describes a bucket that engages the tines of a fork, and therefore can be used with a machine that already has a fork attached. The present disclosure also engages with tines of multiple lengths, meaning that the same bucket will engage with forks from different machines. The bucket has first and second side members; a collecting member extending between the first and second side members; and an engagement portion having an engagement surface and a pocket. | 4 |
This application is a Continuation of U.S. Ser. No. 10/040,472 filed on Jan. 9, 2002, now issued US Pat. No. 6,942,334.
BACKGROUND OF THE INVENTION
The following invention relates to a hand-held computing device, of the type commonly referred to as a personal digital assistant, with an internal printer. More particularly, though not exclusively, the invention relates to a personal digital assistant having a pagewidth drop-on-demand printhead and a source of print media located in the personal digital assistant.
A personal digital assistant, such as the type commonly known under the trade mark Palm Pilot, is typically a hand-held portable electronic device having a fold down display screen and a control panel. The display screen is typically of a touch screen type that reacts to touches made by a user controlling a pixel pen. Alternatively user inputs are provided to the digital assistant through a keypad or in-built curser ball.
Personal digital assistants provide a user with the convenience to be able to store diaries, address books, meeting schedules etc in a compact, transportable form as well as to be able to instantly add new entries such as meeting notes, new addresses etc..
Much of the benefit of such portable prior art personal digital assistants is lost however if a print-out of any stored information is required. To print information, prior art digital assistants must be connected to a print device compatible with the digital assistant which requires additional cabling to be carried thus reducing the portability of the digital assistant. Alternatively the digital storage medium that stores the images within the digital assistant must be transferred to another computer having compatible software for reading the storage medium and which is connected to a printer. Each of the above alternatives can only be implemented if these other computing devices are readily at hand. The prior art personal digital assistants are thus yet to reach their maximum potential as a functional medium for storing and transporting information. With the advent of mobile communications technologies potentially allowing electronic commerce to be conducted through one's digital assistant, it is becoming essential that digital assistants have more suitable print capabilities for printing hard copies of the information stored in the digital assistant.
However, presently, printer technology has not been suitable for incorporating into personal digital assistants without a significant compromise in the size and portability of such devices.
OBJECTS OF THE INVENTION
It is an object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.
It is another object of the present invention to provide a personal digital assistant having an in-built printer.
It is a further object of the invention to provide a personal digital assistant having an in-built printer without significantly increasing the size over prior art digital assistants.
It is a further object of the present invention to provide a personal digital assistant from which stored information can be printed without connecting the digital assistant to additional computing or printing devices.
DISCLOSURE OF THE INVENTION
There is disclosed herein a hand held personal digital assistant including information storage means, display means, in-built printer means, control means allowing a user to selectively retrieve and display information from said storage means on said display means and to print said information using said printer means and means allowing a user to enter and store new information in said information storage means.
Preferably the personal digital assistant includes a body section connected to said display means through a hinge joint, said body section housing said information storage means and said control means, wherein at least a portion of said printer means is disposed in said hinge joint.
Preferably the printer means includes a supply of print media located within said personal digital assistant.
Preferably said supply of print media is located substantially within said hinge.
Preferably a printhead of the printer is a monolithic pagewidth printhead.
Preferably the printhead is an ink jet printhead.
Preferably the body or hinge includes a releasable cover portion through which a portion of the printer including the print media and/or an ink cartridge can be removed.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which:
FIG. 1 shows a three dimensional view of a print engine, including components in accordance with the invention;
FIG. 2 shows a three dimensional, exploded view of the print engine;
FIG. 3 shows a three dimensional view of the print engine with a removable print cartridge used with the print engine removed;
FIG. 4 shows a three dimensional, rear view of the print engine with the print cartridge shown in dotted lines;
FIG. 5 shows a three dimensional, sectional view of the print engine;
FIG. 6 shows a three dimensional, exploded view of a printhead sub-assembly of the print engine;
FIG. 7 shows a partly cutaway view of the printhead sub-assembly;
FIG. 8 shows a sectional end view of the printhead sub-assembly with a capping mechanism in a capping position;
FIG. 9 shows the printhead sub-assembly with the capping mechanism in its uncapped position;
FIG. 10 shows an exploded, three dimensional view of an air supply arrangement of the print engine;
FIG. 11 shows a personal digital assistant having a built in printer;
FIG. 12 shows the internal components of a personal digital assistant having a built in printer;
FIG. 13 shows a personal digital assistant with a releasable cover portion; and
FIG. 14 is a schematic block diagram of components incorporated into a personal digital assistant having a built-in printer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1 to 10 of the accompanying drawings, reference numeral 500 generally designates a print engine, in accordance with the invention. The print engine 500 includes a print engine assembly 502 on which a print roll cartridge 504 is removably mountable.
The print cartridge 504 is described in greater detail in our co-pending applications U.S. Ser. No. 09/607,993 and U.S. Ser. No. 09/607,251, the contents of that disclosure being specifically incorporated herein by reference.
The print engine assembly 502 comprises a first sub-assembly 506 and a second, printhead sub-assembly 508 .
The sub-assembly 506 includes a chassis 510 . The chassis 510 comprises a first molding 512 in which ink supply channels 514 are molded. The ink supply channels 514 supply inks from the print cartridge 504 to a printhead 516 ( FIGS. 5 to 7 ) of the printhead sub-assembly 508 . The printhead 516 prints in four colors or three colors plus ink which is visible in the infra-red light spectrum only (hereinafter referred to as ‘infra-red ink’). Accordingly, four ink supply channels 514 are defined in the molding 512 together with an air supply channel 518 . The air supply channel 518 supplies air to the printhead 516 to inhibit the build up of foreign particles on a nozzle guard of the printhead 516 .
The chassis 510 further includes a cover molding 520 . The cover molding 520 supports a pump 522 thereon. The pump 522 is a suction pump, which draws air through an air filter in the print cartridge 504 via an air inlet pin 524 and an air inlet opening 526 . Air is expelled through an outlet opening 528 into the air supply channel 518 of the chassis 510 .
The chassis 510 further supports a first drive motor in the form of a stepper motor 530 . The stepper motor 530 drives the pump 522 via a first gear train 532 . The stepper motor 530 is also connected to a drive roller 534 ( FIG. 5 ) of a roller assembly 536 of the print cartridge 504 via a second gear train 538 . The gear train 538 engages an engageable element 540 ( FIG. 2 ) carried at an end of the drive roller 534 . The stepper motor 530 thus controls the feed of print media 542 to the printhead 516 of the sub-assembly 508 to enable an image to be printed on the print media 542 as it passes beneath the printhead 516 . It also to be noted that, as the stepper motor 530 is only operated to advance the print media 542 , the pump 522 is only operational to blow air over the printhead 516 when printing takes place on the print media 542 .
The molding 512 of the chassis 510 also supports a plurality of ink supply conduits in the form of pins 544 which are in communication with the ink supply channels 514 . The ink supply pins 544 are received through an elastomeric collar assembly 546 of the print cartridge 504 for drawing ink from ink chambers or reservoirs 548 ( FIG. 5 ) in the print cartridge 504 to be supplied to the printhead 516 .
A second motor 550 , which is a DC motor, is supported on the cover molding 520 of the chassis 510 via clips 552 . The motor 550 is provided to drive a separating means in the form of a cutter arm assembly 554 to part a piece of the print media 542 , after an image has been printed thereon, from a remainder of the print media. The motor 550 carries a beveled gear 556 on an output shaft thereof. The beveled gear 556 meshes with a beveled gear 558 carried on a worm gear 560 of the cutter assembly 554 . The worm gear 560 is rotatably supported via bearings 562 in a chassis base plate 564 of the printhead sub-assembly 508 .
The cutter assembly 554 includes a cutter wheel 566 , which is supported on a resiliently flexible arm 568 on a mounting block 570 . The worm gear 560 passes through the mounting block 570 such that, when the worm gear 560 is rotated, the mounting block 570 and the cutter wheel 566 traverse the chassis base plate 564 . The mounting block 570 bears against a lip 572 of the base plate 564 to inhibit rotation of the mounting block 570 relative to the worm gear 560 . Further, to effect cutting of the print media 542 , the cutter wheel 566 bears against an upper housing or cap portion 574 of the printhead sub-assembly 508 . This cap portion 574 is a metal portion. Hence, as the cutter wheel 566 traverses the capped portion 574 , a scissors-like cutting action is imparted to the print media to separate that part of the print media 542 on which the image has been printed.
The sub-assembly 506 includes an ejector mechanism 576 . The ejector mechanism 576 is carried on the chassis 510 and has a collar 578 having clips 580 , which clip and affix the ejector mechanism 576 to the chassis 510 . The collar 578 supports an insert 582 of an elastomeric material therein. The elastomeric insert 582 defines a plurality of openings 584 . The openings 584 close off inlet openings of the pins 544 to inhibit the ingress of foreign particles into the pins 544 and, in so doing, into the channels 514 and the printhead 516 . In addition, the insert 584 defines a land or platform 586 which closes off an inlet opening of the air inlet pin 524 for the same purposes.
A coil spring 588 is arranged between the chassis 510 and the collar 578 to urge the collar 578 to a spaced position relative to the chassis 510 when the cartridge 504 is removed from the print engine 500 , as shown in greater detail in FIG. 3 of the drawings. The ejector mechanism 576 is shown in its retracted position in FIG. 4 of the drawings.
The printhead sub-assembly 508 includes, as described above, the base plate 564 . A capping mechanism 590 is supported displaceably on the base plate 564 to be displaceable towards and away from the printhead 516 . The capping mechanism 590 includes an elongate rib 592 arranged on a carrier 593 . The carrier is supported by a displacement mechanism 594 , which displaces the rib 592 into abutment with the printhead 516 when the printhead 516 is inoperative. Conversely, when the printhead 516 is operational, the displacement mechanism 594 is operable to retract the rib 592 out of abutment with the printhead 516 .
The printhead sub-assembly 508 includes a printhead support molding 596 on which the printhead 516 is mounted. The molding 596 , together with an insert 599 arranged in the molding 596 , defines a passage 598 through which the print media 542 passes when an image is to be printed thereon. A groove 700 is defined in the molding 596 through which the capping mechanism 590 projects when the capping mechanism 590 is in its capping position.
An ink feed arrangement 702 is supported by the insert 599 beneath the cap portion 574 . The ink feed arrangement 702 comprises a spine portion 704 and a casing 706 mounted on the spine portion 704 . The spine portion 704 and the casing 706 , between them, define ink feed galleries 708 which are in communication with the ink supply channels 514 in the chassis 510 for feeding ink via passages 710 ( FIG. 7 ) to the printhead 516 .
An air supply channel 711 ( FIG. 8 ) is defined in the spine portion 704 , alongside the printhead 516 .
Electrical signals are provided to the printhead 516 via a TAB film 712 which is held captive between the insert 599 and the ink feed arrangement 702 .
The molding 596 includes an angled wing portion 714 . A flexible printed circuit board (PCB) 716 is supported on and secured to the wing portion 714 . The flex PCB 716 makes electrical contact with the TAB film 712 by being urged into engagement with the TAB film 712 via a rib 718 of the insert 599 . The flex PCB 716 supports busbars 720 thereon. The busbars 720 provide power to the printhead 516 and to the other powered components of the print engine 500 . Further, a camera print engine control chip 721 is supported on the flex PCB 716 together with a QA chip (not shown) which authenticates that the cartridge 504 is compatible and compliant with the print engine 500 . For this purpose, the PCB 716 includes contacts 723 , which engage contacts 725 in the print cartridge 504 .
As illustrated more clearly in FIG. 7 of the drawings, the printhead itself includes a nozzle guard 722 arranged on a silicon wafer 724 . The ink is supplied to a nozzle array (not shown) of the printhead 516 via an ink supply member 726 . The ink supply member 726 communicates with outlets of the passages 710 of the ink feed arrangement 702 for feeding ink to the array of nozzles of the printhead 516 , on demand.
In FIG. 10 , the air supply path for supplying air to the printhead 516 is shown in greater detail. As illustrated, the pump 522 includes an impeller 728 closed off by an end cap 730 . The cover molding 520 of the chassis forms a receptacle 732 for the impeller 728 . The cover molding 520 has the air inlet opening 734 and the air outlet opening 736 . The air inlet opening 734 communicates with the pin 524 . The air outlet opening 736 feeds air to the air supply channel 518 which, in FIG. 10 , is shown as a solid black line. The air fed from the air supply channel 518 is blown into the printhead 516 to effect cleaning of the printhead. The air drawn in via the pump 522 is filtered by an air filter 738 , which is accommodated in the print cartridge 504 . The air filter 738 has a filter element 740 which may be paper based or made of some other suitable filtering media. The filter element 740 is housed in a canister, having a base 742 and a lid 744 . The lid 744 has an opening 746 defined therein. The opening 746 is closed off by a film 748 which is pierced by the pin 524 . The advantage of having the air filter 738 in the print cartridge 504 is that the air filter 738 is replaced when the print cartridge 504 is replaced.
It is an advantage of the invention that an air pump 522 is driven by the stepper motor 530 , which also controls feed of the print media to the printhead 516 . In so doing, fewer components are required for the print engine 500 rendering it more compact. In addition, as the same motor 530 is used for operating the air pump 522 and for feeding the print media 542 to the printhead 516 , fewer power consuming components are included in the print engine 500 rendering it more compact and cheaper to produce.
It is also to be noted that, in order to make the print engine 500 more compact, the size of the print engine assembly 502 is such that most of the components of the assembly 502 are received within a footprint of an end of the print cartridge 504 .
In FIG. 11 there is depicted a personal digital assistant having an internal printer. The digital assistant 901 includes a body section 902 housing the main circuitry of the digital assistant including a digital storage medium. A display screen 904 is pivotably connected to the body section 902 about a hinge joint 905 . The screen 904 pivots between a closed position ( FIG. 12 ) where the screen lies adjacent the body section 902 thus allowing safe transport, and an open position ( FIG. 11 ) where the screen 904 is visible to a user.
The body section 902 includes a control panel 906 on an upper surface thereof that includes all buttons required to operate the functions of the digital assistant including the functions of the printer. Using this control panel, a user can selectively view any stored information and make any new entries or amendments. The control panel also includes keys allowing the user to selectively print any of the stored information. A slot 910 in the front edge of the body is used for ejecting printed media 911 .
The display screen is of a known touch screen type allowing a user to control the digital assistant using a compatible pixel pen (not shown) through which the user selects items on a displayed menu. In addition the digital assistant may include known pattern recognition software that allows a user to enter information by writing on the screen whereafter the user's input is analysed and converted into text.
In FIG. 14 there is schematically depicted in block diagram form the key internal components of a personal digital assistant having an internal printer. The printer would typically utilize a monolithic printhead 814 which could be the same as described above with reference to FIGS. 1 to 10 , but could alternatively be another compact printhead capable of printing on suitably sized print media. Print data from the memory 909 of the digital assistant or a display screen dump 904 is fed to a print engine controller 813 which controls the printhead 814 .
A micro-controller 807 associated with the print engine controller controls a motor driver 809 which in turn drives a media transport device 810 . This might be the same as stepper motor 530 described earlier.
The micro-controller 807 also controls a motor driver 811 which in turn controls a guillotine motor 812 to sever a printed sheet from an in-built roll of print media after an image is printed. A sheet being driven by media transport device 810 is shown at 911 in FIG. 11 . The guillotine might be of the form of cutter wheel 566 described earlier.
When ready, printer control buttons on the control panel can be depressed to activate the print engine controller to print stored information either from memory or as a screen dump from the display screen. This would in turn activate the micro-controller 807 to activate the media transport 810 and guillotine 812 .
FIG. 12 shows an internal view of the personal digital assistant in its closed position. The printer engine 500 described previously is disposed within the body section 902 with the removable print media cartridge 504 being disposed in the hinge joint 905 linking the body section 902 with the display screen 904 . Printed media ejected from the print media passage 548 of the print engine travels substantially along the inner surface of the bottom panel of the body section 902 and exits the digital assistant at ejector slot 910 . Because the print roll 504 is disposed within the hinge joint 905 , the personal digital assistant of the present invention can be made substantially the same size as prior art digital assistants The body section 902 and hinge 905 include a releasable portion 912 pivotably connected through a hinge 913 and secured in a closed position by a catch 914 . Opening of this portion ( FIG. 13 ) allows the ink containing print roll cartridge 504 to be removed and replaced. Further details of a removable print roll cartridge are described in our co-pending application U.S. Ser. No. 09/607,993 mentioned earlier.
While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. It will further be understood that any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates. | A hand held personal digital assistant including: memory for storing information; a display; a pagewidth print head; a processor for processing information to generate dot data and supply it to the printhead; a receptacle including an ink interface, the receptacle being configured to receive a cartridge containing at least one ink, the ink being supplied to the printhead via the ink interface; a user interface configured to enable; retrieval of the information from the memory for display on the display; printing of the displayed information; and input of further information for storage, display and printing. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 08/130,995 now U.S. Pat. No. 5,489,716, filed Oct. 4, 1993, which is a continuation of application Ser. No. 07/625,699, filed on Dec. 12, 1990, which application is a continuation of application Ser. No. 07/317,589, filed on Mar. 1, 1989 (now abandoned).
BACKGROUND OF THE INVENTION
This invention relates to a process for producing L-tryptophan, L-tyrosine or L-phenylalanine by fermentation. L-tryptophan is an amino acid useful as a medicament, food, an additive for animal feed, etc.; L-tyrosine is an amino acid useful especially as a medicament; and L-phenylalanine is an amino acid useful in the pharmaceutical and food industries.
Heretofore, various processes for producing L-tryptophan by fermentation using coryneform glutamic acid-tryptophan producing bacteria have been known; for example, a process using a microorganium belonging to the genus Corynebacterium, requiring L-tyrosine and L-phenylalanine and being resistant to at least of tyrosine analogues and phenylalanine analogues (Japanese Published Examined Patent Application No. 19037/1976); a process using a microorganism resistant to tryptophan analogues, such as 5-methyltryptophan (Japanese Published Examined Patent Application Nos. 18828/1973, 38795/1976 and 39517/1978); a process using a microorganism requiring histidine (Japanese Published Examined Patent Application No. 4505/1972); and a process using a Brevibacterium strain whose pyruvate kinase activity is decreased or lacked (Japanese Published Unexamined Patent Application No. 25339/1987).
Further, various processes for producing L-tyrosine or L-phenylalanine by fermentation using coryneform glutamic acid-producing bacteria have been known; for example, a process using an auxotrophic mutant strain requiring amino acids, a mutant strain resistant to amino acid analogues, a mutant strain whose pyruvate kinase activity is decreased or lacked, or a strain having these properties simultaneously [Nippon Nogeikagaku Kaishi, 50 (1), p.R 79 (1979); Japanese Published Unexamined Patent Application No. 128897/1986].
On the other hand, microorganisms capable of producing L-tyrosine or L-phenylalanine have been constructed by recombinant DNA technique. As an example of L-tyrosine-producing microorganism, a strain carrying a recombinant DNA containing a gene coding for 3-deoxy-D-arabino-hepturosonate-7-phosphate synthase (hereinafter referred to as DS), a gene coding for chorismate mutase (hereinafter referred to as CM) and a gene coding for prephenate dehydrogenase or pretyrosine aminotransferase, is known (Japanese Published Unexamined Patent Application No. 34197/1985). As an example of L-phenylalanine-producing microorganism, a strain carrying a recombinant DNA containing a gene coding for DS or genes coding for CM and prephenate dehydratase (hereinafter referred to as PD), are known (Japanese Published Unexamined Patent Application Nos. 24192/1985, 260892/1986 and 124375/1986).
With the recent increase in the demand for L-tryptophan, L-tyrosine and L-phenylalanine, improved processes for the industrial production thereof are desired.
As a result of intensive studies to obtain a new strain with higher L-tryptophan, L-tyrosine or L-phenylalanine productivity, the present inventors have found that if strains of coryneform glutamic acid-producing bacteria that are capable of producing L-tryptophan, L-tyrosine or L-phenylalanine are mutated to be decreased or lacked in phosphoenolpyruvate carboxylase (EC. 4.1.1.31) (hereinafter referred to as PC) activity, they acquire high productivity of these amino acids.
SUMMARY OF THE INVENTION
This invention provides a process for producing L-tryptophan, L-tyrosine or L-phenylalanine, which comprises culturing in a medium a coryneform glutamic acid-producing bacteium being capable of producing L-tryptophan, L-tyrosine or L-phenylalanine and also decreased or lacked in PC activity, and recovering L-tryptophan, L-tyrosine or L-phenylalanine accumulated in the culture broth therefrom.
DETAILED DESCRIPTION OF THE INVENTION
The coryneform glutamic acid-producing bacterium herein referred to is a microorganism belonging to the genus Corynebacterium or Brevibacterium.
As the mutant strains of the present invention, all the coryneform glutamic acid-producing bacteria that are capable of producing L-tryptophan, L-tyrosine or L-phenylalanine and also decreased or lacked in PC activity can be used. The mutant strains of the present invention can be derived from any coryneform glutamic acid-producing bacterium. Examples of the suitable parent strains are as follows.
______________________________________Corynebacterium glutamicum ATCC13032Corynebacterium acetoacidophilum ATCC13870Corynebacterium herculis ATCC13868Corynebacterium lilium ATCC15990Brevibacterium flavum ATCC14067Brevibacterium lactofermentum ATCC13869Brevibacterium divaricatum ATCC14020Brevibacterium thiogenitalis ATCC19240______________________________________
L-tryptophan-producing strains can be derived from the above coryneform glutamic acid-producing bacteria by imparting requirements for tyrosine and phenylalanine and/or resistance to tryptophan analogues such as 5-methyltryptophan thereto. An example of the L-tryptophan-producing strain is Corynebacterium glutamicum ATCC 21851.
L-tyrosine-producing strains can be derived from the coryneform glutamic acid-producing bacteria by imparting requirements for L-phenylalanine and/or resistance to amino acid analogues thereto, or by introduction of a recombinant DNA that contains genes coding for DS, CM, and prephenate dehydrogenase or pretyrosine aminotransferase (Japanese Published Unexamined Patent Application No. 34197/1985). Furthermore, the L-tyrosine-producing strains can also be obtained by introducing, into an L-tryptophan-producing microorganism, a recombinant DNA comprising a DNA fragment involved in the genetic information of enzymes participating in the biosynthesis of L-tyrosine, such as DS and CM, and thereby converting the L-tryptophan-producing strain into an L-tyrosine-producing strain (Japanese Published Unexamined Patent Application No. 94985/1988).
L-phenylalanine-producing strains can be derived from the coryneform glutamic acid-producing bacteria by imparting requirements for L-tyrosine and/or resistance to amino acid analogues thereto, or by introduction of a recombinant DNA that contains genes coding for DS, or CM and PD (Japanese Published Unexamined Patent Application Nos. 24192/1985, 260892/1986 and 124375/1986). Furthermore, L-phenylalanine-producing strains can also be obtained by introducing, into an L-tryptophan-producing microorganism, a recombinant DNA comprising a DNA fragment involved in the genetic information participating in the synthesis of DS, CM and PD, and thereby converting the L-tryptophan-producing microorganism into an L-phenylalanine-producing strain (Japanese Published Unexamined Patent Application No. 105688/1988).
The L-tryptophan-, L-tyrosine- or L-phenylalanine-producing microorganisms whose PC activity is decreased or lacked can be obtained from a known L-tryptophan-, L-tyrosine- or L-phenylalanine-producing strain through mutation that causes such a change in PC activity. Alternatively, the microorganisms of the present invention can also be obtained by imparting auxotrophy and/or resistance to amino acid analogues to a mutant strain whose PC activity is decreased or lacked.
The microorganisms whose PC activity is decreased lacked may be obtained by mutagenizing cells with conventional methods, for example, ultraviolet irradiation and treatment with chemical mutagens such as N-methyl-N'-nitro-N-nitrosoguanidine (hereinafter referred to as NTG) and nitrous acid, followed by isolation as an L-glutamic acid requiring strain. A mutant strain decreased in PC activity may also be isolated as a strain more sensitive to an affinity labeling reagent of the enzyme, or as a prototrophic revertant of the L-glutamic acid-requiring strain lacking PC activity. The affinity labeling reagent, which is also called active-site-directed irreversible inhibitor, is a compound capable of specifically binding to the active center of an enzyme and thereby inactivating the catalytic activity.
Examples of the strain whose PC activity is decreased or lacked are Corynebacterium glutamicum BPS-13 which is capable of producing L-tryptophan, Corynebacterium glutamicum K77 which is capable of producing L-tyrosine, and Corynebacterium glutamicum K78 which is capable of producing L-phenylalanine.
Production of L-tryptophan, L-tyrosine or L-phenylalanine by a microorganism of the present invention can be carried out in a conventional manner used for the production of amino acids. Either a synthetic medium or a natural medium can be used so long as it contains carbon sources, nitrogen sources, inorganic substances, growth factors, and the like.
As the carbon sources, carbohydrates such as glucose, glycerol, fructose, sucrose, maltose, mannose, starch, starch hydrolyzate and molasses; polyalcohols; and various organic acids such as pyruvic acid, fumaric acid, lactic acid and acetic acids may be used. Hydrocarbons and alcohols may also be used, depending on the assimilability of the microorganism to be used. Of these, cane molasses is preferably used.
As the nitrogen sources, ammonia; various organic and inorganic ammonium salts such as ammonium chloride, ammonium sulfate, ammonium carbonate and ammonium acetate; urea and other nitrogen-containing compounds; and nitrogen-containing organic compounds, such as peptone, NZ-amine, meat extract, yeast extract, corn steep liquor, casein hydrolyzate, fish meal or its digested product are appropriate.
As the inorganic compounds, mention is made of potassium monohydrogen phosphate, potassium dihydrogen phosphate, ammonium sulfate, ammonium chloride, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate and calcium carbonate.
Culturing is carried out under aerobic conditions by shaking culture, aeration-stirring culture, etc. The preferred culturing temperature is generally from 20° to 40° C. The pH of the medium is maintained at around neutrality. The culturing time is generally in the range from 1 to 5 days. L-tryptophan, L-tyrosine or L-phenylalanine can be isolated from the culture by removing the microbial cells through filtration or centrifugation, and recovering the amino acid from the filtrate or supernatant according to known procedures, such as crystallization by concentration, treatment with active charcoal and treatment with an ion-exchange resin.
The following Examples will further illustrate the present invention.
EXAMPLE 1
Isolation of a mutant strain whose PC activity is decreased
(1) L-Tryptophan-producing strain
Corynebacterium glutamicum ATCC21851 capable of producing L-tryptophan was used as the parent strain. It was cultured in a complete medium (a medium containing 20 g/l powdered bouillon and 5 g/l yeast extract in water; pH 7.2) at 30° C. for 16 hours. The cells collected were washed with 0.05M phosphate buffer solution (pH 7.2) and suspended in the above-mentioned buffer solution to a concentration of 10 9 cells/ml. NTG was added to this suspension to a final concentration of 500 μg/ml, and the mixture was held at 30° C. for 20 minutes. The cells thus treated were washed with the above-mentioned buffer solution and spread on a minimal agar medium having a composition shown in Table 1, further containing 0.5 μg/ml 3-bromopyruvic acid (hereinafter referred to as 3BP), which is a compound known as an affinity labeling reagent for PC [J. Biochem., 86, 1251-1257 (1979)].
TABLE 1______________________________________Composition of Minimal Agar Medium______________________________________Glucose 10 g/l(NH.sub.4)H.sub.2 PO.sub.4 1 g/lKC1 0.2 g/lMgSO.sub.4.7H.sub.2 O 0.2 g/lFeSO.sub.4.7H.sub.2 O 10 mg/lMnSO.sub.4.4-6H.sub.2 O 0.2 mg/lZnSO.sub.4.7H.sub.2 O 0.9 mg/lCuSO.sub.4.5H.sub.2 O 0.4 mg/lNa.sub.2 B.sub.4 O.sub.7.10H.sub.2 O 0.09 mg/l(NH.sub.4).sub.6 Mo.sub.7 O.sub.24.4H.sub.2 O 0.04 mg/lBiotin 0.05 mg/lp-Aminobenzoic acid 2.5 mg/lThiamin hydrochloride 1 mg/lL-Tyrosine 50 mg/lL-Phenylalanine 50 mg/lAgar 16 g/l (pH 7.2)______________________________________
Culturing was carried out at 30° C. for 5 to 10 days, and smaller colonies were picked up from the colonies grown on the plate medium. Strains more sensitive to 3BP than the parent strain were then selected, and a strain whose PC activity was decreased, Corynebacterium glutamicum BPS-13, was finally isolated from the mutant strains sensitive to 3BP.
This strain was deposited on Mar. 2, 1988 with the Fermentation Research Institute, Agency of Industrial Science and Technology, Japan (FRI), under deposition number of FERM BP-1777.
The sensitivity to 3BP of the parent strain ATCC21851 and of the mutant strain BPS-13, and their activities of PC and pyruvate kinase (hereinafter referred to as PK) were shown in Table 2. The 3BP sensitivity was evaluated by spreading each of the two strains on the minimal agar medium having the composition shown in Table 1, further containing different concentrations of 3BP, culturing the strain at 30° C. for 4 days, and observing the degree of growth. The PC activity and PK activity were measured by the method described in J. Biochem., 66 (3), 297-311 (1969) and Agric. Biol. Chem., 48 (5), 1189-1197 (1984), using crude cell extracts. The crude cell extracts were prepared according to the procedure given below. Each of the strains was inoculated to a medium (pH 7.2) containing 30 g/l glucose, 0.5 g/l MgSO 4 .7H 2 O, 10 mg/l FeSO 4 .7H 2 O, 1 g/l KH 2 PO 4 , 1 mg/l MnSO 4 .4H 2 O, 4 g/l ammonium sulfate, 2 g/l urea, 50 μg/l biotin, 2.5 mg/l p-aminobenzoic acid, 1 mg/l thiamin hydrochloride, 50 mg/l sodium chloride, 50 mg/l L-tyrosine and 50 mg/l L-phenylalanine, and subjected to shaking culture at 30° C. for 24 hours. The grown cells were collected, washed twice with 0.2% aqueous potassium chloride solution, suspended in 0.1M Tris-HCl buffer solution (pH 7.5), and disrupted by ultrasonic waves. The resulting mixture was centrifuged, and the supernatant was dialyzed overnight against the above-mentioned buffer solution to obtain the crude cell extract. The values shown in Table 2 are given by calculating the specific activity per unit amount of protein contained in the crude extracts, and obtaining the relative value when the specific activity for the parent strain is defined as 100.
TABLE 2______________________________________ Concn. of 3BP (μg/ml) PC PKStrain 0 1 3 10 30 (%) (%)______________________________________ATCC21851 ++ ++ + ± - 100 100(Parent strain)BPS-13 ++ ± - - - 25 138(FERM BP-1777)______________________________________
(2) L-Tyrosine-producing strain
Corynebacterium glutamicum ATCC21851 capable of producing L-tryptophan was transformed with recombinant plasmid pCDS-CMl containing DS and CM genes as described in Japanese Published Unexamined Patent Application No. 94985/1988, and Corynebacterium glutamicum T6 strain (ATCC21851/pCDS-CM1) capable of producing L-tyrosine was isolated according to the procedure described in the same patent application as mentioned above. That is, the ATCC21851 strain was cultured in NB medium (a medium containing 20 g/l powdered bouillon and 5 g/l yeast extract in water; pH 7.2). Then, 4 ml of the seed culture thus obtained was inoculated to 40 ml of semi-synthetic medium SSM [a medium containing 20 g/l glucose, 10 g/l (NH 4 ) 2 SO 4 , 3 g/l urea, 1 g/l yeast extract, 1 g/l KH 2 PO 4 , 0.4 g/l MgCl 2 .6H 2 O, 10 mg/l FeSO 4 .7H 2 O, 0.2 mg/l MnSO 4 .4-6H 2 O, 0.9 mg/l ZnSO 4 .7H 2 O, 0.4 mg/l CuSO 4 .5H 2 O, 0.09 mg/l Na 2 B 4 O 7 .10 H 2 , 0.04mg/l (NH 4 ) 6 Mo 7 O 24 .4H 2 O, 30 μg/l biotin and 1 mg/l thiamin hydrochloride in water; pH 7.2] further containing 100 μg/ml each of L-tyrosine and L-phenylalanine, and shaking culture was carried out at 30° C. The optical density (OD) at 660 nm was determined with a Tokyo Koden colorimeter and when the OD reached 0.2, penicillin G was added to a final concentration of 0.5 unit/ml. Shaking culture was further continued until OD reached 0.6. The microbial cells were collected, and suspended to a final concentration of about 10 9 cells/ml in 10 ml of RCGP medium [a medium containing 5 g/l glucose, 5 g/l casamino acid, 2.5 g/l yeast extract, 3.5 g/l K 2 HPO 4 , 1.5 g/l KH 2 PO 4 , 0.41 g/l MgCl 2 .6H 2 O, 10 mg/l FeSO 4 .7H 2 O, 2 mg/l MnSO 4 .4-6H 2 O, 0.9 mg/l ZnSO 4 .7H 2 O, 0.04 mg/l (NH 4 ) 6 Mo 7O 24 .4H 2 O, 30 μg/l biotin, 2 mg/l thiamin hydrochloride, 135 g/l disodium succinate and 30 g/l polyvinyl pyrrolidone (M.W.: 10,000) in water; pH 7.6] further containing 1 mg/ml lysozyme. The suspension thus obtained was transferred to an L-type test tube and gently shaken at 30° C. for 5 hours to induce protoplasts.
The resulting protoplast-suspension (0.5 ml) was taken into a small test tube, and centrifuged for 5 minutes at 2,500×g, and the protoplasts collected were suspended in 1 ml of TSMC buffer solution (10 mM MgCl 2 , 30 mM CaCl 2 , 50 mM Tris and 400 mM sucrose; pH 7.5) and washed by centrifugation. The protoplasts were resuspended in 0.1 ml of TSMC buffer solution. Then, 10 μl of TSMC buffer solution containing 1 μg pCDS-CMl plasmid DNA was added to the suspension, and 0.8 ml of TSMC buffer solution containing 20% PEG6000 (Nakarai Chemicals) was further added. Then, 2 ml of RCGP medium (pH 7.2) was added 3 minutes after, and the mixture was centrifuged for 5 minutes at 2,500×g, to remove a supernatant. The precipitated protoplasts were suspended in 1 ml of RCGP medium. The suspension thus obtained (0.2 ml) was spread on RCGP agar medium (RCGP medium containing 1.4% agar; pH 7.2) further containing 400 μg/ml spectinomycin, and cultured at 30° C. for 7 days. The strain grown on the agar medium was isolated as a transformant.
Corynebacterium glutamicum T6 strain thus obtained (ATCC21851/pCDS-CMl) was subjected to mutation in the same manner as described in Example 1 (1), and L-tyrosine-producing Corynebacterium glutamicum K77 strain whose PC activity was decreased was isolated as a 3BP-sensitive mutant strain. The K77 strain was deposited on Sep. 21, 1988 with FRI under deposition number of FERM BP-2062. 3BP-sensitivity, PC activity and PK activity of parent strain T6 and mutant strain K77 were measured in the same manner as in Example 1 (1). The results are given in Table 3.
TABLE 3______________________________________ Concn. of 3BP (μg/ml) PC PKStrain 0 1 3 10 30 (%) (%)______________________________________T6 (parent strain) ++ ++ + ± - 100 100(ATCC21851/pCDS-CM1)K77 ++ + - - - 36 102(FERM BP-2062)______________________________________
(3) L-phenylalanine-producing strain
L-phenylalanine-producing Corynebacterium glutamicum T17 strain (ATCC21851/pEaroG-pheA3) was obtained by transforming L-tryptophan-producing Corynebacterium glutamicum ATCC21851 with the recombinant plasmid pEaroG-pheA3 containing DS, CM and PD genes of Escherichia coli as disclosed in Japanese Published Unexamined Patent Application No. 105688/1988 in the same manner as in Example 1 (2), except that RCGP-agar medium containing 200 μg/ml kanamycin was used for the screening of transformant.
L-phenylalanine-producing Corynebacterium glutamicum T17 strain (ATCC21851/pEaroG-pheA3) thus obtained was subjected to mutation in the same manner as in Example 1 (1), and L-phenylalanine-producing Corynebacterium glutamicum K78 strain whose PC activity was decreased was isolated. The K78 strain was deposited on Sep. 21, 1988 with FRI under deposition number of FERM BP-2063. 3BP-sensitivity, PC activity and PK activity of parent strain T17 and mutant strain K78 were measured in the same manner as in Example 1 (1). The results are given in Table 4.
TABLE 4______________________________________ Concn. of 3BP (μg/ml) PC PKStrain 0 1 3 10 30 (%) (%)______________________________________T17 (parent strain) ++ ++ + ± - 100 100(ATCC21851/pEaroG-pheA3)K78 ++ ± - - - 22 96(FERM BP-2063)______________________________________
EXAMPLE 2
(1) Production test of L-tryptophan
Corynebacterium glutamicum BPS-13 (FERM BP-1777) was inoculated in a 300-ml Erlenmeyer flask containing 20 ml of a seed medium (2% glucose, 1.5% polypeptone, 1.5% yeast extract, 0.25% sodium chloride, 0.1% urea, 200 mg/1 L-tyrosine and 200 mg/l L-phenylalanine; pH 7.2), and shaking culture was carried out at 30° C. for 24 hours on a rotary shaker set at 210 rpm. The seed culture thus obtained (2 ml) was then inoculated in a 300-ml Erlenmeyer flask containing 20 ml of a fermentation medium of the following composition, and cultured for 72 hours under the same conditions as above. The parent strain ATCC21851 was also cultured as control in the same manner as described above. After culturing, each of the culture filtrates was subjected to paper chromatography and after color formation with ninhydrin, the amount of L-tryptophan produced was measured by colorimetric quantitative determination.
The result is shown in Table 5.
Composition of fermentation medium: 6% glucose, 0.05% KH 2 PO 4 , 0.05% K 2 HPO 4 , 0.025% MgSO 4 .7H 2 O, 2% ammonium sulfate, 30 μg/l biotin, 10 mg/l MnSO 4 .7H 2 O, 0.5% corn steep liquor and 2% CaCO 3 (pH 7.2)
TABLE 5______________________________________ Amount of L-tryptophanStrain produced (mg/ml)______________________________________ATCC21851 6.0(parent strain)BPS-13 7.8(FERM BP-1777)______________________________________
(2) Production test of L-tyrosine
Corynebacterium glutamicum K77 (FERM BP-2062) was inoculated in a 300-ml Erlenmeyer flask containing 20 ml of a seed medium (2% glucose, 1.5% polypeptone, 1.5% yeast extract, 0.25% sodium chloride and 0.1% urea; pH 7.2), and shaking culture was carried out at 30° C. for 24 hours on a rotary shaker set at 210 rpm. The seed culture thus obtained (2 ml) was then inoculated in a 300-ml Erlenmeyer flask containing 20 ml of a fermentation medium having the same composition as in Example 2 (1), and cultured for 72 hours under the same conditions as mentioned above. Separately, the parent strain T6 (ATCC21851/pCDS-CM1) was also cultured as control in the same manner.
After culturing, the culture broth thus obtained (1 ml each) was admixed with 50 μl of 6N-NaOH solution, and heated at 65° C. for 5 minutes to completely dissolve the L-tyrosine precipitated. The culture filtrate was subjected to paper chromatography and after color formation with ninhydrin, the amount of L-tyrosine produced Was measured by colorimetric quantitative determination.
The result is shown in Table 6.
TABLE 6______________________________________ Amount of L-tyrosineStrain produced (mg/ml)______________________________________T6 4.5(ATCC21851/pCDS-CM1)K77 5.8(FERM BP-2062)______________________________________
(3) Production test of L-phenylalanine
Corynebacterium glutamicum K78 (FERM BP-2063) and its parent strain T17 (ATCC21851/pEaroG-pheA3) were cultured in the same manner as in Example 2 (2). After culturing, each of the culture filtrates was subjected to paper chromatography and after color formation with ninhydrin, the amount of L-phenylalanine produced was measured by colorimetric quantitative determination.
The result is shown in Table 7.
TABLE 7______________________________________ Amount of L-phenylalanineStrain produced (mg/ml)______________________________________T17 4.8(ATCC21851/pEaroG-pheA3)K78 6.0(FERM BP-2063)______________________________________ | The invention relates to a bacterial process for producing L-tryptophan, L-tyrosine or L-phenylalanine. The process utilizes a coryneform glutamic acid-producing bacterium being capable of producing L-tryptophan, L-tyrosine or L-phenylalanine and also decreased or lacked in phosphoenolpyruvate carboxylase activity. The mutant strain is then cultured in order to accumulate the amino acid in a medium and the amino acid is recovered therefrom. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Divisional Application which claims priority to application Ser. No. 11/011,730 filed Dec. 14, 2004.
BACKGROUND OF THE INVENTION
[0002] This invention relates to air treatment modules and, more particularly, to protecting a photocatalyst in the air treatment module using a corona discharge device to remove contaminants from the air handling air stream.
[0003] Air treatment modules are commonly used in automotive, commercial and residential heating, ventilating, and air conditioning (HVAC) systems to move and purify air. Typically, an air stream flowing through the air treatment module includes trace amounts of contaminants such as biospecies, dust, particles, odors, carbon monoxide, ozone, semi-volatile organic compounds (SVOCs), volatile organic compounds (VOCs) such as formaldehyde, acetaldehyde, toluene, propanol, butene, and silicon-containing VOCs.
[0004] Typically, a filter and a photocatalyst are used to purify the air stream by removing and/or destroying the contaminants. A typical filter includes a filter media that physically separates contaminants from the air stream. A typical photocatalyst includes a titanium dioxide coated monolith, such as a honeycomb, and an ultraviolet light source. The titanium dioxide operates as a photocatalyst to destroy contaminants when illuminated by ultraviolet light. Photons of the ultraviolet light are absorbed by the titanium dioxide, promoting an electron from the valence band to the conduction band, thus producing a hole in the valence band and adding an electron in the conduction band. The promoted electron reacts with oxygen, and the hole remaining in the valence band reacts with water, forming reactive hydroxyl radicals. When contaminants in the air stream flow through the honeycomb and are adsorbed onto the titanium dioxide coating, the hydroxyl radicals attack and oxidize the contaminants to water, carbon dioxide, and other substances. The ultraviolet light also kills the biospecies in the airflow that are irradiated.
[0005] Disadvantageously, typical air treatment module filters have a finite contaminant capacity. Once the contaminant capacity is reached, the filter does not physically separate additional contaminants from the air stream. Contaminants in the air stream may then flow through the filter and become oxidized by the photocatalyst. This is particularly troublesome when the photocatalyst oxidizes silicon-containing VOCs or SVOCs to form a silicon-based glass on the photocatalyst surface. The silicon-based glass may insulate the titanium dioxide from the passing air stream, thereby passivating the titanium dioxide. In severe instances, much of the catalytic activity of the photocatalyst may be lost within two weeks of reaching the contaminant capacity of the filter. To prevent photocatalyst passivation, the filter may be replaced before reaching the contaminant capacity or additional filters may be utilized to physically separate a greater amount of the contaminants, however, the maintenance required to replace a filter in short time intervals or continually monitor a filter may be expensive and inconvenient.
[0006] Accordingly, an air treatment module that more effectively protects the photocatalyst from passivating contaminants is needed.
SUMMARY OF THE INVENTION
[0007] A gas treatment system for treating a gas stream containing contaminants includes first and second gas treatment members in fluid communication with each other. Each of the first and second gas treatment members is selectively controllable between an on and an off condition. A third gas treatment member is in fluid communication with the first and second gas treatment members, and the third gas treatment member selectively retains or releases the contaminants based upon the on or off condition of at least one of the first or second gas treatment members.
[0008] The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a HVAC system including an air treatment module.
[0010] FIG. 2 is a perspective view of an example air treatment module.
[0011] FIG. 3 is a schematic view of an example filter, plasma device, and photocatalyst.
[0012] FIG. 4 is a schematic view another example of the filter of FIG. 3 .
[0013] FIG. 5 is a schematic view an example air treatment module that includes an ozone-destroying material.
[0014] FIG. 6 is a schematic view of another air treatment module configuration that includes a second plasma device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIG. 1 illustrates a residential, commercial, vehicular, or other structure 10 including an interior space 12 , such as a room, office or vehicle cabin. An HVAC system 14 heats or cools the interior space 12 . Air in the interior space 12 is drawn into the HVAC system 14 through an inlet path 16 . The HVAC system 14 changes the temperature and purifies the air drawn using an air treatment module 18 . The purified, temperature-changed air is then returned to the interior space 12 through an outlet path 20 .
[0016] FIG. 2 illustrates a perspective view of an example air treatment module 18 . The air treatment module 18 includes a compressor 30 for drawing and returning the air. Air drawn from the interior space 12 flows in an air stream 32 into a filter cabinet 34 , which forms an air flow path through the air treatment module 18 . The filter cabinet 34 encloses a filter 36 , plasma device 38 , and photocatalyst 40 that cooperate to purify the air stream 32 . The air stream 32 continues through the filter cabinet to the coils 42 . The coils 42 heat or cool the air stream 32 , depending on the desired interior space 12 temperature. After being heated or cooled, the compressor 30 returns the air stream 32 to the interior space 12 through the outlet path 20 . It is to be understood that the air treatment module 18 shown is only one example and that the invention is not limited to such a configuration.
[0017] FIG. 3 illustrates a schematic view of an example filter 36 , plasma device 38 , and photocatalyst 40 . The filter 36 receives the air stream 32 and adsorbs contaminants from the air stream 32 . The filter 36 includes a known activated carbon filter media held between layers of a fibrous mesh 44 . In one example, the known activated carbon is modified, impregnated, or pore-controlled. As is known, a modifier such as potassium permanganate or other modifier may be impregnated in the activated carbon to modify the adsorptive properties of the activated carbon. The pore volume of the activated carbon may also be controlled within a desired range to modify the adsorptive properties. These features may provide the advantage of designing the filter 36 to preferentially adsorb certain contaminants, such as formaldehyde, acetaldehyde, toluene, propanol, butene, silicon-containing VOCs, or other VOCs.
[0018] In another example, the filter 36 may additionally utilize a zeolite and/or other type of filter media mixed with the activated carbon between the layers of fibrous mesh 44 to obtain preferential adsorption of certain contaminants. Alternatively, the activated carbon filter media may be integrated with the fibrous mesh 44 by coating the activated carbon onto fibers that make the fibrous mesh 44 .
[0019] In another example, the activated carbon filter media is provided in a first layer 46 and the zeolite media and/or other filter media may be provided in an adjacent second layer 48 , as illustrated in FIG. 4 .
[0020] A heating element 50 , which is discussed in more detail below, surrounds the filter 36 and is selectively operable between and on and an off condition.
[0021] In one example, the plasma device 40 is located generally downstream from the filter 36 and is selectively operable between an on and an off condition. Preferably the plasma device 38 is a corona discharge device that generates a plasma glow discharge. Even more preferably, the plasma device 38 includes a biased electrode 54 , such as a wire cathode.
[0022] The photocatalyst 40 is, in one example, located downstream from the plasma device 38 . Preferably the photocatalyst 40 is a titanium dioxide coated monolith, such as a honeycomb, that operates as a photocatalyst to destroy contaminants when illuminated with an ultraviolet (UV) light 56 . It is to be understood that photocatalyst materials other than titanium dioxide and configurations other than shown (for example, integrating the photocatalyst 40 with the filter 36 in a single unitary fibrous or honeycomb structure) may be utilized.
[0023] The UV light 56 is selectively operable between an on condition in which the photocatalyst 40 operates to destroy contaminants, and an off condition in which the photocatalyst 40 is inoperable. In one example, the UV light 56 illuminates the photocatalyst 40 with UV-C range wavelengths, however, other UV wavelength ranges may be utilized depending on the type of photocatalyst and/or air purifying needs of the air treatment module 18 .
[0024] Operationally, the exemplary air treatment module 18 functions in two different modes. In the first mode, the air treatment module 18 functions primarily to move air from and return air to the interior space 12 and to purify the air. In the first mode, the heating element 50 is selectively turned off, the plasma device 38 is selectively turned off, and the UV light 56 is selectively turned on. Thus, the filter 36 captures, traps, and adsorbs certain contaminants from the air stream 32 , such as VOCs and SVOCs, and the photocatalyst 40 operates to destroy other contaminants that pass through the filter 36 . The heating element 50 and plasma device 38 do not function in the first mode, however, in other examples it may be advantageous to simultaneously operate the heating element 50 and plasma device 38 with the functions of filtering and moving the air.
[0025] In the second mode, the air treatment module 18 functions primarily to regenerate the filter 36 . That is, the activated carbon or other adsorbent filter media is conditioned to desorb the previously adsorbed contaminants. The air stream 32 is shut off such that there is essentially zero air flow in the filter cabinet 34 . The heating element 50 is selectively turned on and heats the filter 36 to approximately 100° C., although other heating temperatures or heating profiles may also be utilized. The filter 36 desorbs and releases the contaminants previously adsorbed. The plasma device 38 is selectively turned on and generates a plasma, and the UV light 56 is preferably turned off to prevent the photocatalyst 40 from oxidizing the released contaminants.
[0026] The filter cabinet 34 holds the released contaminants and acts essentially as a reactor vessel for the plasma device 38 . The released contaminants, such as VOCs, SVOCs, or other contaminants that the filter 36 was designed to adsorb/release, contact the plasma generated by the plasma device 38 . The plasma chemically transforms the contaminants into solid contaminant products and deposits the solid contaminant products onto a receiving portion, the biased electrode 54 . Once deposited, the essentially immobile and inert solid contaminant products are unlikely to damage the photocatalyst 40 . In one example, the plasma deposits the solid contaminant products onto a wire cathode. After a predetermined number of deposit cycles, the wire cathode is removed from the plasma device 38 and discarded or cleaned.
[0027] While in the second mode, the heating element 50 and plasma device 38 operate for a selected predetermined amount of time. Preferably, the time is adequate to i) release most of the contaminants from the filter 36 , and thus regenerate the filter 36 and ii) transform the contaminants to solid contaminant products. The time required will vary with temperature, size and type of filter media, size of the filter cabinet 34 , and the size and type of plasma device 38 used.
[0028] Preferably, the UV light 56 remains off when switching from the second mode to the first mode to protect the photocatalyst 40 from any remaining contaminants that have not been transformed to solid contaminant products. The air stream 32 flows through the filter cabinet 34 for a selected predetermined amount of time to purge the remaining released contaminants before turning on the UV light 56 to operate the photocatalyst 40 .
[0029] In another example, the contaminant products include organic silicon compounds, such as silicon-containing VOCs and silicon-containing SVOCs. The filter 36 releases the organic silicon compounds upon heating and the plasma generated by the plasma device 38 chemically transforms the organic silicon compounds into silicon dioxide or other silicon-based glass. The plasma deposits the silicon dioxide or other silicon-based glass on the biased electrode 54 .
[0030] In another example, the filter 36 includes a single pleated layer with a pleating factor of about 8 and about 100 g of activated carbon filter media. The filter 36 adsorbs approximately 90% of the organic silicon compounds in the incoming air stream 32 and takes approximately twelve hours to reach full capacity in first mode operation. Near the twelve hour time, the air treatment module 18 utilizes, for example, a controller to automatically switch into the second mode and regenerate the filter 36 . Alternatively or in addition to the controller, an operator may control the switching between modes.
[0031] In another example shown in FIG. 5 , an ozone-destroying material 58 , such as a known metal oxide catalyst, is included between the plasma device 38 and the photocatalyst 40 . The ozone-destroying material 58 may be disposed on a honeycomb structure 60 , for example, and receives ozone from the plasma device 38 before switching the UV light 56 on. The ozone-destroying material 58 adsorbs ozone onto the surface and decomposes the ozone. This feature may provide the advantage of exposing the photocatalyst 40 to less ozone, which may contribute to photocatalyst 40 passivation. It is to be understood that the ozone-destroying material 58 may alternatively be positioned in other locations in the filter cabinet 34 than shown.
[0032] FIG. 6 illustrates a schematic view of another air treatment module 18 configuration including a second plasma device 138 surrounding the filter 36 . The second plasma device 138 includes a biased electrode 154 and operates similarly to and in conjunction with the plasma device 38 to chemically transform released contaminants into solid contaminant products. Utilizing the second plasma device 138 may provide the benefit of shorter times to fully chemically transform the contaminants released from the filter 36 or greater efficiency in transforming the released contaminants. Likewise, a multitude of additional plasma devices may be used.
[0033] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. | A gas treatment system for treating a gas stream containing contaminants includes first and second gas treatment members in fluid communication with each other. Each of the first and second gas treatment members is selectively controllable between an on and an off condition. A third gas treatment member is in fluid communication with the first and second gas treatment members, and the third gas treatment member selectively retains or releases the contaminants based upon the on or off condition of at least one of the first or second gas treatment members. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to discrete cosine transform circuits, and more particularly, to a forward discrete cosine transform and an inverse discrete cosine transform circuit. These transform circuits are particularly suited for use in an MPEG video encoder and an MPEG video decoder.
2. Description of the Related Art
Fast processing of a vast amount of multifarious information is needed to realize multimedia systems. The need for faster information processing has been accomplished by developments in data compression and expansion techniques that directly effect processing speed. Many types of multimedia recording formats in fact utilize data compression and expansion to enhance processing speeds. The "MPEG (Moving Picture Expert Group)" standards are one popular type of standard that defines and governs data compression and expansion techniques. Current MPEG standards are continuing to be established by the MPEG Committee (ISO/IEC JTC1/SC29/WG11) under the ISO (International Organization for Standardization)/IEC (International Electrotechnical Commission).
The MPEG consists of three parts. In part 1 (ISO/IEC IS 11172-1), the MPEG defines a "system" or way of synchronizing and multiplexing the video and audio data. In part 2, (ISO/IEC IS 11172-2), the MPEG defines video standards that govern the format and encoding process for video data and govern decoding process for a video bitstream. In part 3 (ISO/IEC IS 11172-3), the MPEG defines audio standards that govern the format and encoding process for audio data and govern decoding process for an audio bitstream.
At present, there are two MPEG standards, MPEG-1 and MPEG-2, which differ from each other principally in the rate which video and audio data are encoded. The MPEG-1 standard is associated mainly with storage media such as a CD-ROM, and the MPEG 2 standard is associated with a variety of applications including the MPEG-1.
The technical cores described in the MPEG video part are motion compensated prediction (MC) and discrete cosine transform (DCT). The encoding technique which combines the MC and DCT is called a hybrid encoding technique.
Image processing for forming a screen which is to be handled by the MPEG video part, correlates horizontal direction and vertical direction with either one of the horizontal and vertical coordinates of one point (one pixel) on the screen. More specifically, the screen is divided into a plurality of small blocks each including a total of N×N pixels, N pixels in the horizontal direction and N pixels in the vertical direction. Two-dimensional DCT is to be performed on each small block having such N×N pixels. One pixel corresponds to one element in the DCT.
As the value of N gets larger, the encoding efficiency gets better, but the amount of necessary operations increases. That is, the encoding efficiency and the amount of operations are in a tradeoff relation. In the MPEG video part, therefore, N often takes a value of around eight to balance the encoding efficiency with the amount of operations. Basically, the DCT is the signal conversion which, like a Fourier transform, breaks a time signal up into frequency-based signal components. A Fourier transform includes complex number computations where a real-number part and an imaginary-number part are separated. However, one can say that the DCT, in a sense, is a computation to extract only a real-number part from a complex number.
According to the MPEG video part, at the time of encoding, an image signal associated with the formation of a screen is broken by a forward DCT (FDCT) into frequency-based signal components which in turn will be processed. At the time of decoding, frequency-based signal components are restored to an image signal by an inverse DCT (IDCT).
When two-dimensional DCT computation is conventionally executed according to the transform equation, the number of operations becomes significantly large, thus requiring large-scale hardware. To perform the two-dimensional DCT computation on N×N pixels or elements when N=8, for example, 4096 multiplications and 4096 additions are needed. To reduce the number of operations, therefore, it has been proposed to execute much simpler one-dimensional DCT instead of two-dimensional DCT.
More specifically, first, one-dimensional DCT of N elements is performed on N lines in the horizontal direction and then, one-dimensional DCT of N elements is performed on N lines in the vertical direction. This process is equivalent to the execution of two-dimensional DCT of N×N elements. When N=8, one-dimensional DCT requires eight multiplications and eight additions for one element and 64 multiplications and 64 additions for one line. When one-dimensional DCT is performed twice, therefore, the required numbers of multiplications and additions respectively become 16 times greater than those needed in the single execution of one-dimensional DCT, i.e., 1024 multiplications and 1024 additions are needed. This requirement applies to IDCT as well as FDCT.
To increase the speed of the operations for two-dimensional DCT, it is important to not only replace two-dimensional DCT with one-dimensional DCT but also to reduce the number of operations for one-dimensional DCT. In this respect, schemes called "fast algorithms" which simplifies the operations have been proposed. Specifically, when a DCT equation is mathematically developed, one can see several multiplication terms where cosine coefficients to be multipliers become the same. In the fast algorithms, the multiplications having a common cosine coefficient are handled collectively in order to reduce the number of multiplications. The "butterfly operation" is one of such fast algorithms. The conventional MPEG video encoders and MPEG video decoders generally employ this butterfly operation.
When N=8, one-dimensional DCT which uses the butterfly operation requires 16 multiplications and 26 additions for one line. When one-dimensional DCT is performed twice instead of the two-dimensional DCT, the required numbers of multiplications and additions respectively become 16 times greater than those needed in the single execution of one-dimensional DCT, as discussed above so that the DCT based on the butterfly operation just requires 256 multiplications and 416 additions. This requirement applies to IDCT as well as FDCT. The fast algorithm is described in greater detail in "Discrete Cosine Transform Algorithms, Advantages, Applications" by K. R. Rao and P. Yip, ACADEMIC PRESS, INC. 1990.
Even if the operations are simplified by using the fast algorithm, the direct execution of two-dimensional DCT operations involves a significant number of operations and requires large-scale hardware. When N=8, for example, the simple execution of the butterfly operation needs the hardware which includes 256 multiplexers and 416 adders. Generally speaking, it is very difficult or impossible to integrate such numerous operation circuits on a single chip LSI. Even if there are 1000 gates per a single multiplier, a total of over 200,000 gates would be needed for the multipliers for all the operation circuits. The same is true of IDCT as well as FDCT. FIGS. 1A, 1B, 2A and 2B illustrate operation circuits. Each of the operation circuits includes a function block for the operation of one-dimensional DCT and accomplishes the equivalent two-dimensional DCT operation by repeating the function block. Each function block for the one-dimensional DCT operations is smaller than the hardware which directly executes two-dimensional operations.
FIG. 1A shows a two-dimensional FDCT circuit 100 which includes a single one-dimensional FDCT circuit 102. Input data Din is transferred via a controller 101 to the FDCT circuit 102 which performs one-dimensional FDCT. The FDCT circuit 102 performs one-dimensional FDCT operations on the input data Din for N lines in the horizontal direction based on the butterfly operation. The results of the operations are transferred via the controller 101 to a register 103 for temporary storage.
Subsequently, the operational results temporarily stored in the register 103 are transferred via the controller 101 to the one-dimensional FDCT circuit 102. The FDCT circuit 102 performs one-dimensional FDCT operations on the operational results for N lines in the vertical direction. As a result, output data Dout is obtained which is the results of the two-dimensional FDCT of N×N elements. The output data Dout is output from the two-dimensional FDCT circuit 100 via the controller 101. The intermediate values attained in each FDCT operation in the horizontal direction and the vertical direction are also stored in the register 103.
When N=8, the one-dimensional FDCT circuit 102 can be constituted of 16 multipliers and 26 adders. When N=8, the two-dimensional FDCT circuit 100 should operate the FDCT circuit 102 a total of 16 times, eight times in each of the horizontal and vertical directions. Because the FDCT circuit 102 performs its operations based on the butterfly operation, it requires six clocks for one operation (i.e., for the one-dimensional FDCT operation of eight elements). Therefore, the time needed for the two-dimensional FDCT operation of 8×8 elements is 96 (=6×16) clocks.
As shown in FIG. 1B, a two-dimensional IDCT circuit 105 is constructed by replacing the FDCT circuit 102 in FIG. 1A with a one-dimensional IDCT circuit 104. When the IDCT circuit 104 employs the butterfly operation and when N=8, the IDCT circuit 104, like the FDCT circuit 102, can be constructed by 16 multipliers and 26 adders and needs six clocks for a single operation (for the one-dimensional IDCT operation of eight elements). The time needed for the two-dimensional IDCT operation of 8×8 elements is 96 clocks as in the case of the FDCT operation.
FIG. 2A shows a two-dimensional FDCT circuit 110 which includes two sets of one-dimensional FDCT circuit blocks. Input data Din is transferred via a controller 111 to an FDCT circuit 112 of N elements. The FDCT circuit 112 performs one-dimensional FDCT operations on the input data Din for N lines in the horizontal direction by using the butterfly operation. The results of the operations are transferred via the controller 111 to a register 114 to be registered there. The intermediate values attained in this FDCT operation are temporarily registered in a register 113.
Subsequently, the operational results temporarily stored in the register 114 are transferred via a controller 121 to a one-dimensional FDCT circuit 122 of N element(s). Using the butterfly operation, the FDCT circuit 122 performs one-dimensional FDCT operations on the operational results for N lines in the vertical direction. As a result, output data Dout is obtained which is the results of the two-dimensional FDCT of N×N elements. This output data Dout is output via the controller 121. The intermediate values attained in this FDCT operation are temporarily registered in a register 123.
As apparent from the above, the two-dimensional FDCT circuit 110 shown in FIG. 2A is equivalent to the circuit structure which has two two-dimensional FDCT circuits 100 in FIG. 1A connected in series. When N=8, each of the one-dimensional FDCT circuits 112 and 122 can be constituted of 16 multipliers and 26 adders. When N=8, the two-dimensional FDCT circuit 110 should operate each FDCT circuit eight times in the associated horizontal direction or vertical direction or should independently operate each of the FDCT circuits 112 and 122 a total of 16 times, eight times in the horizontal and vertical directions, respectively. Because each of the FDCT circuits 112 and 122 employs the butterfly operation, it requires six clocks for one operation (i.e., for the one-dimensional FDCT operation of eight elements). Therefore, the time needed for each FDCT circuit for the two-dimensional FDCT operation of 8×8 elements is 48 (=6×8) clocks.
As shown in FIG. 2B, a two-dimensional IDCT circuit 133 is constructed by replacing the one-dimensional FDCT circuits 112 and 122 of the two-dimensional FDCT circuit 110 with one-dimensional IDCT circuits 131 and 132. Those IDCT circuits 131 and 132 also employ the butterfly operation. When N=8, each of the IDCT circuits 131 and 132, like the FDCT circuit 112 or 122, can be constructed by 16 multipliers and 26 adders and needs six clocks for a single operation (for the one-dimensional IDCT operation of eight elements). The time needed for the two-dimensional IDCT operation of 8×8 elements is 48 clocks as in the case of the FDCT operation.
In the two-dimensional FDCT circuit 110 (or IDCT circuit 133), the FDCT circuits 112 and 122 (or the IDCT circuits 131 and 132) can be operated independently. This is advantageous in pipelining the operation circuits.
Recently, there has been a demand for more compact hardware for MPEG video encoders and MPEG video decoders while further improving the operation speeds. Thus, there is a need for more compact hardware of the two-dimensional FDCT circuit and IDCT circuit while further increasing the operation speeds thereof.
SUMMARY OF THE INVENTION
Broadly speaking, the present invention relates to a forward discrete cosine transform (FDCT) circuit and an inverse discrete cosine transform (IDCT) circuit which are smaller and operator faster than conventional circuits, even those which use a fast algorithm like the butterfly operation. The invention also relates to an MPEG video encoder and an MPEG video decoder which incorporate such FDCT and/or IDCT circuits.
An inverse discrete cosine transform (IDCT) circuit according to an embodiment of the invention includes a group of multipliers, and a group of adders/subtractors. The group of multipliers receive plural pieces of input data externally supplied in parallel. Each multiplier has a cosine constant to multiply to the received input data. The group of adders/subtractors receive multiplication results from the multipliers, and perform addition/subtraction thereon to produce output data, which is the result of inverse discrete cosine transform of the input data.
A forward discrete cosine transform (FDCT) circuit according to an embodiment of the present invention includes a group of input-stage adders/subtractors, a group of multipliers and a group of output-stage adders. The group of input-stage adders/subtractors receives plural pieces of input data externally supplied in parallel, and performs addition/subtraction on the input data. The group of multipliers receive computation results from the input-stage adders/subtractors. Each multiplier has a cosine constant to multiply to a particular one of the received computation results. The group of output-stage adders receive multiplication results from the multipliers, and add the multiplication results to produce output data, which is the result of forward discrete cosine transform of the input data.
Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principals of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIGS. 1A and 1B are block circuit diagrams of conventional art;
FIGS. 2A and 2B are block circuit diagrams of conventional art;
FIG. 3 is a block circuit diagram of an IDCT circuit according to a first embodiment of the invention;
FIG. 4 is a diagram for explaining the operation of the IDCT circuit of the first embodiment;
FIG. 5 is a block circuit diagram of an FDCT circuit according to a second embodiment of the invention;
FIG. 6 is a diagram for explaining the operation of the FDCT circuit of the second embodiment;
FIG. 7 is a block circuit diagram of an FDCT/IDCT circuit according to a third embodiment of the invention;
FIGS. 8A, 8B and 8C are block circuit diagrams of two-dimensional FDCT circuits and/or IDCT circuits according to a fourth embodiment of the invention;
FIGS. 9A, 9B and 9C are block circuit diagrams of two-dimensional FDCT circuits and/or IDCT circuits according to a fifth embodiment of the invention;
FIG. 10 is a block circuit diagram of a two-dimensional FDCT circuit and/or IDCT circuit according to a sixth embodiment of the invention;
FIG. 11 is a block circuit diagram of an MPEG video decoder according to a seventh embodiment of the invention; and
FIG. 12 is a block circuit diagram of an MPEG video encoder according to an eighth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
A one-dimensional IDCT circuit according to a first embodiment of the present invention will now be described with reference to FIGS. 3 and 4. As shown in FIG. 3, a one-dimensional IDCT circuit 1 for eight elements includes eight constant multipliers 11 to 18 and eight adders 21 to 28. The adder 28 serves as a subtractor. Each of the four adders 21-24 at the first stage is coupled to two of the two multipliers associated therewith. Each of the adders 25 and 26 at the second stage receives the outputs of the associated two first-stage adders, and outputs the result of the addition to the adder 27 and the adder 28 at the final stage. The individual multipliers 11-18 respectively receive input data F(x1) to F(x8), and the final-stage adders 27 and 28 respectively produce output data f(y1) and f(y2) which are the results of the IDCT operation on the input data F(x1) to F(x8).
FIG. 4 shows the relationship between the input data F(x1) to F(x8) in the IDCT circuit 1 and the output data f(y1) and f(y2). The individual constant multipliers 11-18 respectively multiply the respective input data F(x1) to F(x8) by their constants C 0 to C 7 . The values of the constants C 0 to C 7 are defined according to the following equation (1).
Ci=cos(i×π/16) i=0.sup.˜ 7! (1)
It is apparent from FIG. 4 that the two multipliers 11 and 14 produce outputs of positive values irrespective of the input values. The other constant multipliers 12, 13, and 15-18 are adapted to produce outputs of positive or negative values in accordance with the input values. In other words, the signs of the outputs of the constant multipliers 12, 13 and 15-18 are set as shown in a table (b) in FIG. 4 in accordance with the combinations of the input data F(x1) to F(x8) shown in a table (a) in FIG. 4. With respect to the combinations of the input data F(x1) to F(x8) shown in the table (a) in FIG. 4, the combinations of the output data f(y1) and f(y2) as shown in a table (c) in FIG. 4 are obtained. For the combination No. 1 in the tables (a)-(c) in FIG. 4, i.e., for F(x1)=F(0), F(x2)=F(1), F(x3)=F(2), F(x4)=F(3), F(x5)=F(4), F(x6)=F(5), F(x7)=F(6), and F(x8)=F(7), for example, the outputs of the individual multipliers 11-18 all become positive values and f(y1)=f(0) and f(y2)=f(7).
The IDCT circuit 1 performs operations expressed by the following equations (2A) to (5B).
f(0)=F(0)C.sub.0 +F(2)C.sub.2 +F(4)C.sub.4 +F(6)C.sub.6 +F(1)C.sub.1 +F(3)C.sub.3 +F(5)C.sub.5 +F(7)C.sub.7 (2A)
f(7)=F(0)C.sub.0 +F(2)C.sub.2 +F(4)C.sub.4 +F(6)C.sub.6 -F(1)C.sub.1 -F(3)C.sub.3 -F(5)C.sub.5 -F(7)C.sub.7 (2B)
f(1)=F(0)C.sub.0 +F(2)C.sub.6 -F(4)C.sub.4 -F(6)C.sub.2 +F(1)C.sub.3 -F(3)C.sub.7 -F(5)C.sub.1 -F(7)C.sub.5 (3A)
f(6)=F(0)C.sub.0 +F(2)C.sub.6 -F(4)C.sub.4 -F(6)C.sub.2 -F(1)C.sub.3 +F(3)C.sub.7 +F(5)C.sub.1 +F(7)C.sub.5 (3B)
f(2)=F(0)C.sub.0 -F(2)C.sub.6 -F(4)C.sub.4 +F(6)C.sub.2 +F(1)C.sub.5 -F(3)C.sub.1 +F(5)C.sub.7 +F(7)C.sub.3 (4A)
f(5)=F(0)C.sub.0 -F(2)C.sub.6 -F(4)C.sub.4 +F(6)C.sub.2 -F(1)C.sub.5 +F(3)C.sub.1 -F(5)C.sub.7 -F(7)C.sub.3 (4B)
f(3)=F(0)C.sub.0 -F(2)C.sub.2 +F(4)C.sub.4 -F(6)C.sub.6 +F(1)C.sub.7 -F(3)C.sub.5 +F(5)C.sub.3 -F(7)C.sub.1 (5A)
f(4)=F(0)C.sub.0 -F(2)C.sub.2 +F(4)C.sub.4 -F(6)C.sub.6 -F(1)C.sub.7 +F(3)C.sub.5 -F(5)C.sub.3 +F(7)C.sub.1 (5B)
This embodiment has the following function and advantages.
Every time the input data F(x1) to F(x8) for eight elements are input to the IDCT circuit 1, two output data f(y1) and f(y2) are attained in accordance with FIG. 4 and the equations (2A) to (5B). In other words, two pixels of output data are obtained with respect to one cycle of one-dimensional IDCT operations for eight elements. Accordingly, eight pixels of output data are produced by four cycles of IDCT operations.
The IDCT circuit 1 according to this embodiment comprises eight multipliers 11-18 and eight adders 21-28, wherein the adder 28 functions as a subtractor. Since the eight multipliers 11-18 can be constructed by 44 adders, the IDCT circuit 1 can be constructed by 52 adders alone.
As multiplications are repeated in the butterfly operation, it is necessary to increase the number of intermediate operation bits (i.e., bit width) between the multipliers and adders in order to secure the necessary operation precision for the conventional IDCT circuit 104 (see FIG. 1B) which employs the butterfly operation. As each of the constant multipliers 11-18 in the IDCT circuit 1 of the first embodiment performs a single constant multiplication, as opposed to the conventional case, the first embodiment requires fewer intermediate operation bits. More specifically, the IDCT circuit 1 of this embodiment needs 16 intermediate operation bits whereas the conventional IDCT circuit 104 needs 18 intermediate operation bits. Therefore, the circuit scale (hardware scale) of the individual adders constituting the IDCT circuit 1 can be made smaller than that of the conventional IDCT circuit 104 which performs the butterfly operation.
In view of the above, the circuit scale of the IDCT circuit 1 of this embodiment can be reduced significantly as compared with the conventional IDCT circuit 104. Namely, when an LSI chip is produced, the circuit scale (chip occupying area) required by the IDCT circuit 1 is a significantly smaller than required by the conventional IDCT circuit 104, largely because the IDCT circuit can be implemented by adders alone which themselves quire less occupying area than multipliers.
The time needed for one cycle operation of the IDCT circuit 1 (the time needed for the one-dimensional IDCT operations for eight elements) is a total of four clocks, one clock for the operations of the constant multipliers 11-18, one clock for the operations of the first-stage adders 21-24, one clock for the operations of the second-stage adders 25 and 26 and one clock for the operations of the final-stage adders 27 and 28. The operation speed of the IDCT circuit 1 of this embodiment is thus faster than that of the conventional IDCT circuit 104.
Second Embodiment
A one-dimensional FDCT circuit according to a second embodiment of the invention will now be described with reference to FIG. 5. To avoid the redundant description, like or same reference numerals are given to those components which are the same as the corresponding components of the first embodiment.
As shown in FIG. 5, a one-dimensional FDCT circuit 31 for eight elements includes eight constant multipliers 11 to 18, a total of eighteen adders 21 to 26 and 32 to 43 and one selector 44. The adders 38 to 43 serve as subtractors. Each of the four first-stage adders 32-35 receives two input data. The second-stage adders include the four adders 36-39 each of which receives the outputs of the associated two first-stage adders, and the four adders 40-43 each of which receives two input data. The second-stage adders 36-43 are connected to the selector 44, which is also connected to the eight multipliers 11-18. Each of the four third-stage adders 21-24 is associated with and coupled to two of the multipliers 11-18. Each of the final-stage adders 25 and 26 receives the outputs from two of the associated third-stage adders 21-24. The FDCT circuit 31 therefore receives input data f(0) to f(7) and outputs output data F(y1) and F(y2), which are the results of the FDCT operations on the input data, from the final-stage adders 25 and 26.
FIG. 6 shows the relationship between the input data f(0) to f(7) and the output data F(y1) and F(y2) in the FDCT circuit 31. As apparent from FIG. 6, the three multipliers 11, 13 and 14 produce outputs of positive values irrespective of the input values. The other five constant multipliers 12 and 15-18 are adapted to produce outputs of positive or negative values in accordance with the input values.
The selector 44 switches the outputs of the adders 36 to 43 on the input side in accordance with switching rules as given in a table (a) in FIG. 6, and provides each of the multipliers 11-18 with the associated selected output.
The individual multipliers 11-18 multiply the associated selected outputs from the selector 44 by their respective constants C 0 to C 7 . The values of the individual constants C 0 -C 7 are given by the aforementioned equation (1). The signs of the outputs of the constant multipliers 12 and 15-18 are set as shown in a table (b) in FIG. 6 in accordance with the selected combinations (No. 1 to No. 4) of the switching rules shown in the table (a) in FIG. 6. In accordance with the selected combination of the switching rules, therefore, output data F(y1) and F(y2) as shown in a table (c) in FIG. 6 are obtained.
For the combination No. 1 in the tables (a)-(c) in FIG. 6, for example, the outputs of the individual multipliers 11-18 all become positive values and F(y1)=F(0) and F(y2)=F(1) with respect to the input data f(0) to f(7).
The FDCT circuit 31 performs operations expressed by the following equations (6A) to (9B).
F(0)=f(0)C.sub.4 +f(1)C.sub.0 +f(2)C.sub.0 +f(3)C.sub.4 +f(4)C.sub.4 +f(5)C.sub.0 +f(6)C.sub.0 +f(7)C.sub.4 (6A)
F(1)=f(0)C.sub.1 +f(1)C.sub.3 +f(2)C.sub.5 +f(3)C.sub.7 -f(4)C.sub.7 -f(5)C.sub.5 -f(6)C.sub.3 -f(7)C.sub.1 (6B)
F(2)=f(0)C.sub.2 +f(1)C.sub.6 -f(2)C.sub.6 -f(3)C.sub.2 -f(4)C.sub.2 -f(5)C.sub.6 +f(6)C.sub.6 +f(7)C.sub.2 (7A)
F(3)=f(0)C.sub.3 -f(1)C.sub.7 -f(2)C.sub.1 -f(3)C.sub.5 +f(4)C.sub.5 +f(5)C.sub.1 +f(6)C.sub.7 -f(7)C.sub.3 (7B)
F(4)=f(0)C.sub.0 -f(1)C.sub.4 -f(2)C.sub.4 +f(3)C.sub.0 +f(4)C.sub.0 -f(5)C.sub.4 -f(6)C.sub.4 +f(7)C.sub.0 (8A)
F(5)=f(0)C.sub.5 -f(1)C.sub.1 +f(2)C.sub.7 +f(3)C.sub.3 -f(4)C.sub.3 -f(5)C.sub.7 +f(6)C.sub.1 -f(7)C.sub.5 (8B)
F(6)=f(0)C.sub.6 -f(1)C.sub.2 +f(2)C.sub.2 -f(3)C.sub.6 -f(4)C.sub.6 +f(5)C.sub.2 -f(6)C.sub.2 +f(7)C.sub.6 (9A)
F(7)=f(0)C.sub.7 -f(1)C.sub.5 +f(2)C.sub.3 -f(3)C.sub.1 +f(4)C.sub.1 -f(5)C.sub.3 +f(6)C.sub.5 -f(7)C.sub.7 (9B)
wherein the constant C 0 is equal to the constant C 4 in the equations 6A and 8A.
The second embodiment has the following function and advantages.
When the input data f(0) to f(7) for eight elements are input to the FDCT circuit 31, two output data F(y1) and F(y2) are acquired in accordance with FIG. 6 and the equations (6A) to (9B). In other words, two pixels of output data are obtained with respect to one cycle of one-dimensional FDCT operations for eight elements.
The FDCT circuit 31 according to this embodiment comprises eight constant multipliers 11-18, eighteen adders 21-26 and 32-43, and one selector 44. Since the eight multipliers 11-18 can be constructed by 44 adders, the FDCT circuit 31 can be constructed by 62 adders and one selector 44. Because the selector 44 can be accomplished by a combination of simple transfer gates, the circuit scale of the selector 44 is considerably smaller than that of each of the adders 21-26 and 32-43. Accordingly, the circuit scale of the FDCT circuit 31 becomes substantially equivalent to the IDCT circuit 1 of the first embodiment with ten additional adders.
As multiplications are repeated in the butterfly operation, it is necessary to increase the number of intermediate operation bits (bit width) between the multipliers and adders in order to secure the necessary operation precision for the conventional FDCT circuit 102 (see FIG. 1A) which employs the butterfly operation. Because each of the constant multipliers 11-18 in the FDCT circuit 31 of the second embodiment performs a single constant multiplication, as opposed to the conventional case, the embodiment requires fewer intermediate operation bits. Therefore, the circuit scale of each of the adders constituting the FDCT circuit 31 can be made smaller than that of the conventional FDCT circuit 102 which performs the butterfly operation.
In view of the above, the circuit scale of the FDCT circuit 31 of this embodiment can be reduced significantly as compared with the conventional FDCT circuit 102. Namely, when an LSI chip is produced, the circuit scale (chip occupying area) required by the FDCT circuit 31 is significantly smaller than required by the conventional FDCT circuit 102, largely because the FDCT circuit 31 can be implemented by adders alone which themselves require less occupying area than multipliers.
The time needed for one cycle operation of the FDCT circuit 31 (the time needed for the one-dimensional FDCT operations for eight elements) is a total of five clocks, one clock for the operations of the first-stage adders 32-35, one clock for the operations of the second-stage adders 36-43, one clock for the operations of the constant multipliers 11-18, one clock for the operations of the third-stage adders 21-24 and one clock for the operations of the final-stage adders 25 and 26. The operation speed of the FDCT circuit 31 of this embodiment is thus faster than that of the conventional FDCT circuit 102.
Third Embodiment
A circuit for both one-dimensional FDCT and IDCT according to a third embodiment of this invention will be now described with reference to FIG. 7. To avoid the redundant description, like or same reference numerals are given to those components which are the same as the corresponding components of the first and second embodiments.
As shown in FIG. 7, a one-dimensional FDCT/IDCT circuit 61 for eight elements includes eight constant multipliers 11 to 18, twenty adders 21 to 28 and 32 to 43, a selector 44 and an input selector 62. The adder 28 serves as a subtractor and the six second-stage adders 38-43 serve as subtractors. The two multipliers 11 and 14 produce positive outputs regardless of the input values, and the other multipliers 12, 13 and 15-18 produce positive or negative outputs in accordance with the input values. The FDCT/IDCT circuit 61 can produce output data f(y1) and f(y2), which are the results of the IDCT operations on the input data F(x1)-F(x8), and output data F(y1) and F(y2), which are the results of the FDCT operations on the input data f(0)-f(7).
In a sense, the FDCT/IDCT circuit 61 is equivalent to the IDCT circuit 1 in FIG. 3 and the FDCT circuit 31 in FIG. 5. The input selector 62 provides the constant multipliers 11-18 with externally supplied input data F(x1)-F(x8) in an IDCT operation mode, and provides those multipliers 11-18 with the associated outputs from the first selector 44 in an FDCT operation mode. The signs of the outputs of the individual multipliers 11-18 are set in accordance with the table (b) in FIG. 4 in IDCT operation mode and are set in accordance with the table (b) in FIG. 6 in FDCT operation mode.
The output data f(y1) and f(y2) in the IDCT operation mode are output from the adders 27 and 28 and the output data F(y1) and F(y2) in the FDCT operation mode are output from the adders 25 and 26. In the FDCT/IDCT circuit 61, the IDCT operation and the FDCT operation are switched one from to the other by selectively switching the input data by means of the input selector 62 and by switching the positive and negative signs of the outputs of the individual multipliers 11-18 as appropriate.
The relationship between the input data F(x1) to F(x8) and the output data f(y1) and f(y2) in the FDCT/IDCT circuit 61, like the IDCT circuit 1 of the first embodiment, depends on the relationship shown in FIG. 4 and by the equations (2A) to (5B). The relationship between the input data f(0) to f(7) and the output data F(y1) and F(y2) in the FDCT/IDCT circuit 61, like the FDCT circuit 31 of the second embodiment, depends on the relationship shown in FIG. 6 and by the equations (6A) to (9B). The FDCT/IDCT circuit 61 has both the functions of the IDCT circuit 1 and the FDCT circuit 31.
The FDCT/IDCT circuit 61 comprises eight constant multipliers 11-18, twenty adders 21-28 and 32-43 and two selectors 44 and 62. Since the eight multipliers 11-18 can be accomplished by 44 adders, the FDCT/IDCT circuit 61 can be constructed by 64 adders and two selectors 44 and 62. As each of the selectors 44 and 62 can be accomplished by a combination of simple transfer gates, the circuit scale of which is considerably smaller than that of each of the adders 21-26 and 32-43. Accordingly, the circuit scale of the FDCT/IDCT circuit 61 is substantially equivalent to the FDCT circuit 31 of the second embodiment with two additional adders.
Basically, the FDCT/IDCT circuit 61 has the same function and advantages as the IDCT circuit 1 of the first embodiment at the time of executing IDCT operations, and has the same function and advantages as the FDCT circuit 31 of the second embodiment at the time of executing FDCT operations.
Fourth Embodiment
A two-dimensional FDCT circuit and/or IDCT circuit according to the fourth embodiment of the invention is now described with reference to FIGS. 8A, 8B and 8C.
FIG. 8A shows a two-dimensional FDCT circuit 70 of 8×8 elements according to this invention. This circuit 70 includes a controller 71, a register 72 and the FDCT circuit 31 of the second embodiment. Input data Din is transferred via the controller 71 to the FDCT circuit 31, which in turn performs one-dimensional FDCT on the received input data Din for eight lines in the horizontal direction. The operational results are transferred via the controller 71 to the register 72 to be registered. Then, the operational results held in the register 72 are transferred via the controller 71 to the FDCT circuit 31. The FDCT circuit 31 performs one-dimensional FDCT operations on the operational results for eight lines in the vertical direction. Accordingly, output data Dout is obtained as the results of the two-dimensional FDCT of 8×8 elements. The output data Dout is output from the two-dimensional FDCT circuit 70 via the controller 71.
The two-dimensional FDCT circuit 70 operates the FDCT circuit 31 16 times in total, eight times in the horizontal direction and eight times in the vertical direction. As mentioned earlier, the time needed for the FDCT circuit 31 to complete a single operation (the time for the one-dimensional FDCT operation of eight elements) is five clocks. Thus, the time needed for a two-dimensional FDCT operation for 8×8 elements becomes 80 (=16×5) clocks. Therefore, the two-dimensional FDCT circuit 70 of this embodiment can operate faster than the conventional two-dimensional FDCT circuit 100 (see FIG. 1A).
A two-dimensional IDCT circuit 73 of 8×8 elements can be constructed by replacing the FDCT circuit 31 in FIG. 8A with the IDCT circuit 1 of the first embodiment as shown in FIG. 8B. The time needed for the IDCT circuit 1 to complete a single operation (the time for the one-dimensional IDCT operation of eight elements) is four clocks, as mentioned earlier. Thus, the time needed for a two-dimensional IDCT operation for 8×8 elements becomes 64 (=16×4) clocks. Therefore, the two-dimensional IDCT circuit 73 of this embodiment can operate faster than the conventional two-dimensional IDCT circuit 105 (see FIG. 1B).
The FDCT circuit 31 in FIG. 8A may be replaced with the FDCT/IDCT circuit 61 of the third embodiment to realize a circuit as shown in FIG. 8C.
Fifth Embodiment
A two-dimensional FDCT circuit and/or IDCT circuit according to a fifth embodiment of this invention will be now described with reference to FIGS. 9A, 9B and 9C.
FIG. 9A shows a two-dimensional FDCT circuit 80 of 8×8 elements according to the fifth embodiment of the invention. The FDCT circuit 80 includes two controllers 81 and 82, one register 83 and two FDCT circuits 31a and 31b (each identical to the FDCT circuit 31 of the second embodiment). Input data Din is transferred via the first controller 81 to the first FDCT circuit 31a, which in turn performs one-dimensional FDCT on the received input data Din for eight lines in the horizontal direction. The operational results are transferred via the first controller 81 to the register 83 to be stored therein. Next, the operational results held in the register 83 are transferred via the second controller 82 to the second FDCT circuit 31b. The second FDCT circuit 31b performs one-dimensional FDCT operations on the operational results for eight lines in the vertical direction. Accordingly, output data Dout is obtained as the results of the two-dimensional FDCT of 8×8 elements. The output data Dout is output from the two-dimensional FDCT circuit 80 via the second controller 82.
The two-dimensional FDCT circuit 80 independently operates the FDCT circuits 31a and 31b eight times each, or operates the FDCT circuit 31a eight times in the horizontal direction and the FDCT circuit 31b eight times in the vertical direction. The time needed for the FDCT circuits 31a and 31b to complete a single operation is five clocks. Thus, the time needed for a two-dimensional FDCT operation for 8×8 elements becomes 40 (=8×5) clocks. Therefore, the two-dimensional FDCT circuit 80 of this embodiment can operate faster than the conventional two-dimensional FDCT circuit 110 (see FIG. 2A).
The conventional two-dimensional FDCT circuit 110 needs the registers 113 and 123 for temporarily storing the intermediate values obtained in the butterfly operation. The two-dimensional FDCT circuit 80 of the fifth embodiment however does not need such registers; hence, its circuit scale is smaller than that of the conventional two-dimensional FDCT circuit 110.
Each of the FDCT circuits 31a and 31b in FIG. 9A may be replaced with the IDCT circuit 1 of the first embodiment to realize a two-dimensional IDCT circuit 84 of 8×8 elements as shown in FIG. 9B. The time needed for the IDCT circuit 1 to complete a single operation is four clocks. Thus, the time needed for a two-dimensional IDCT operation for 8×8 elements is 32 (=8×4) clocks. Therefore, the two-dimensional IDCT circuit 84 of this embodiment can operate faster than the conventional two-dimensional IDCT circuit 133 (see FIG. 2B). Because it is unnecessary to provide the registers 113 and 123 for temporarily storing the intermediate values obtained in the butterfly operation, the circuit scale of the two-dimensional IDCT circuit 84 of this invention is smaller than that of the conventional two-dimensional IDCT circuit 133.
Each of the FDCT circuits 31a and 31b in FIG. 9A may be replaced with the FDCT/IDCT circuit 61 of the third embodiment to realize a two-dimensional FDCT/IDCT circuit as shown in FIG. 9C.
Since the circuits as shown in FIGS. 9A, 9B and 9C can independently operate the FDCT circuits 31a and 31b (the IDCT circuit 1 or the FDCT/IDCT circuit 61), the circuits are further thus advantageous because operations are able to be pipelined by the circuits.
Sixth Embodiment
A two-dimensional FDCT circuit and/or IDCT circuit according to the sixth embodiment of the invention will now be described with reference to FIG. 10.
FIG. 10 shows a two-dimensional FDCT circuit 90 of 8×8 elements, which includes first and second serial-parallel converters 91 and 92, first and second sorters 93 and 94, a rounding circuit 95, a RAM (Random Access Memory) 96 for temporary storage and the FDCT circuit 31 of the second embodiment.
Input data Din consisting of 12 bits is converted to data for eight pixels by the first serial-parallel converter 91 and this converted data is sent to the first sorter 93. There are four sorting patterns for the first sorter 93, and the FDCT circuit 31 provides output data for every two pixels for each sorting pattern. When the data processing for the four sorting patterns is completed, output data for eight pixels are obtained and are then stored in the RAM 96.
The instant the 8-pixel output data are obtained, the next eight pixels of data are input to the first serial-parallel converter 91. The next eight pixels of data are subjected to one-dimensional FDCT operation and 8-pixel output are stored in the RAM 96 as in the aforementioned manner. As the above processing is repeated eight times, 64 pixels of output data are stored in the RAM 96. Then, the inputs to the first sorter 93 are switched so that the first sorter 93 are connected via the second serial-parallel converter 92 to the RAM 96 to read the stored data therefrom. The processing similar to the one discussed above is performed on the read data by the second serial-parallel converter 92, the sorter 93 and the FDCT circuit 31. The rounding circuit 95 performs rounding on the operational results output from the FDCT circuit 31.
Thereafter, the same processing is repeated eight times, and the last data obtained is sorted by the second sorter 94, thus yielding output data Dout as the results of the two-dimensional FDCT of 8×8 elements.
This two-dimensional FDCT circuit 90 is equivalent to a circuit obtained by replacing the controller 71 in the two-dimensional FDCT circuit 70 in FIG. 8A with the circuits 91-95 and replacing the register 72 with the RAM 96 for temporary storage. Like the two-dimensional FDCT circuit 70, therefore, this two-dimensional FDCT circuit 90 can perform fast operations.
The FDCT circuit 31 in FIG. 10 may be replaced with the IDCT circuit 1 of the first embodiment to accomplish a two-dimensional IDCT circuit 97 of 8×8 elements. The FDCT circuit 31 in FIG. 10 may be also replaced with the FDCT/IDCT circuit 61 of the third embodiment.
Seventh Embodiment
An MPEG video decoder according to the seventh embodiment of the invention will be now discussed with reference to FIG. 11. An MPEG video decoder 200 shown in FIG. 11 includes a variable length decoder 201, an inverse quantizer 202, a two-dimensional IDCT circuit 73 as shown in FIG. 8B, and a motion vector restoring circuit 203.
The variable length decoder 201 receives a video stream as a stream of compressed video data from transmission media 204 and performs variable length decoding based on the Huffman codes stored in a Huffman table (not shown) provided in the decoder 201. The transmission media 204 include a communications medium like LAN (Local Area Network), storage media like DVD (Digital Video Disk) and VTR (Video Tape Recorder), and broadcasting media like the ground broadcasting, satellite broadcasting and CATV (Community Antenna Television).
The inverse quantizer 202 performs inverse quantization on the results of the decoding by the variable length decoder 201, based on quantization threshold values stored in an incorporated quantization table (not shown), to obtain DCT coefficients. The IDCT circuit 73 performs IDCT on the DCT coefficients computed by the inverse quantizer 202.
The motion vector restoring circuit 203 restores the motion vectors with respect to the processing results from the IDCT circuit 73 to produce video outputs or data obtained by expanding the video stream. The video outputs are supplied to a display 205.
Because the two-dimensional IDCT circuit 73 used in this embodiment can operate fast and has a small hardware scale, the MPEG video decoder 200 can also operate fast and has a small hardware scale. The IDCT circuit 73 in this embodiment may be replaced with the aforementioned IDCT circuit 84 or 97.
Eighth Embodiment
An MPEG video encoder according to an eighth embodiment of the invention is now discussed with reference to FIG. 12. An MPEG video encoder 300 shown in FIG. 12 includes a motion compensation circuit 301, an FDCT circuit 70 as shown in FIG. 8A, a quantizer 302, and a variable length encoder 303.
A video camera 304 senses an image to produce an image input of expanded data. The motion compensation circuit 301 receives the image input from the video camera 304 and produces motion vectors based on the image input. The FDCT circuit 70 performs FDCT on the image input from the video camera 304.
The quantizer 302 performs quantization on the processing results from the FDCT circuit 70, based on quantization threshold values stored in an incorporated quantization table (not shown). The variable length encoder 303 performs variable length encoding on the processing results from the quantizer 302 to produce a video stream as compressed video data of the image input. The video stream is transmitted via transmission media 204 to the MPEG video decoder 200 as discussed in the section concerning the seventh embodiment.
Because the two-dimensional FDCT circuit 70 used in this embodiment can operate fast and has a small hardware scale, the MPEG video encoder 300 can also operate fast and has a small hardware scale. The FDCT circuit 70 in this embodiment may be replaced with the aforementioned FDCT circuit 80 or 90.
Although only eight embodiments of the present invention have been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that this invention may be embodied in the following forms.
Although the foregoing descriptions of the first and third embodiments have discussed one-dimensional IDCT circuits of eight elements, the invention may more generally be adapted to a one-dimensional IDCT circuit of N elements (N being a natural number). Although the foregoing descriptions of the second and third embodiments have discussed one-dimensional FDCT circuits of eight elements, the invention may more generally be adapted to a one-dimensional FDCT circuit of N elements (N being a natural number other than "8"). Further, while the foregoing descriptions of the fourth and fifth embodiments have discussed two-dimensional FDCT circuits and/or IDCT circuits of 8×8 elements, the invention may more generally be adapted to a two-dimensional FDCT circuit and/or IDCT circuit of N×N elements. As N gets bigger in those cases, the encoding efficiency gets better but the number of operations increases. That is, there is a tradeoff relation between the encoding efficiency and the number of operations.
The signal processing by the individual circuits (1-97) in the first to sixth embodiments may be implemented by software executing on a CPU.
The invention may be adapted for not only an MPEG video decoder but also all other types of data processing apparatus which use DCT. The invention may also be adapted for data processing systems which are originated from the MPEG system or data processing systems which include the MPEG system.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | Discrete cosine transform circuits suitable for inverse discrete cosine transform (IDCT) or forward discrete cosine transform (FDCT) are disclosed. An IDCT circuit includes a group of multipliers and a group of adders/subtracters. The multipliers receive plural pieces of input data which are externally supplied in parallel. Each multiplier has a cosine constant to multiply to the received input data. The adders/subtracters receive multiplication results from the multipliers and perform addition/subtraction thereon to produce output data, which is the result of inverse discrete cosine transform of the input data. An FDCT circuit includes a group of input-stage adders/subtracters, a group of multipliers, and a group of output-stage adders. The input-stage adders/subtracters perform addition/subtraction on input data which are externally supplied in parallel. Computation results of the input-stage adders/subtracters is supplied to the multipliers. The output-stage adders receive multiplication results from the multipliers and produce output data, which is the result of forward discrete cosine transform of the input data. The discrete cosine transform circuits are particularly suitable for use in MPEG video encoders/decoders. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of U.S. patent application Ser. No. 11/602,491 filed Nov. 21, 2006, which in turn claims priority under 35 U.S.C. §119(e) to U.S. provisional patent application No. 60/597,297 filed Nov. 21, 2005. Each application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to methods and systems for allowing a person, such as a finder of a valuable or other object, to communicate with the owner of the valuable or other object.
BACKGROUND OF INVENTION
[0003] All U.S. patents referred to herein are hereby incorporated by reference in their entireties. In the case of conflict, the present specification, including definitions, will control.
[0004] For as long as there have been portable possessions, there have been opportunities to for them to be mislaid or go missing. When such possessions have intrinsic, subjective and/or sentimental value, the loss can be especially difficult for the owner of the possession. In today's society such possessions and objects might include a ring of keys, a portable music player with a large music collection, a laptop computer, a digital camera containing the only copy of treasured family photos, or any number of portable objects.
[0005] One time-tested method of protecting against the permanent loss of an object is for the owner to write her name and contact information, for example, a phone number and an address, on the object or on a tag or label attached to the object. Then, when the object is lost or otherwise separated from its owner, a person finding the object can use the name and contact information to contact the owner and communicate arrangements for the return of the object to the object's owner. However, this approach has drawbacks. First, such an approach provides information about the owner's identity to an unknown person. If the lost object were a ring of keys, a finder with mal-intent could use the information on the tag to discern the identity and address of the owner and then use the keys to gain access to her residence. Second, such an approach may not provide contact information with the best currency—such as when the owner is traveling or has recently moved. If the information on the tag is not current and the finder cannot quickly communicate with the owner, an opportunity may be lost for the finder to return the object to the owner before the owner continues in her travels.
[0006] Another method for tagging possessions to protect against their loss is referred to in U.S. Pat. No. 6,259,367 to Klein. This patent refers to the use of RFID tags encoded with “obfuscated” owner information. The RFID encoded information may be used to retrieve a file containing more detailed owner contact information. A drawback to Klein's approach is that a finder must gain access to an RFID tag reader and appropriate software to decode the information and access the file through a network. When this is done through a third party, either the third party must disclose the owner's private contact information or the finder must trust the third party to return the item to the owner. As with conventional tags, Klein's system may lack the most current contact information, create delays (and lost opportunities) in returning possessions, and result in the loss of owner privacy.
[0007] Other systems purport to overcome these disadvantages but fall short. Some require the use of a shipping intermediary in order to return the object to its owner. Some require a third party intermediary to process a “found” report and provide return instructions to a finder.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes the disadvantages of the prior systems by providing for a timely and anonymous communication channel between a finder of an object and an owner of an object.
[0009] In accordance with one aspect of the invention, there is a method of facilitating communication between a finder of an article and an owner of the article which includes providing a unique ID to the owner, allowing the owner to register an association between the ID and owner contact information, allowing the owner to associate the ID and a virtual locale (for example, a website address) with the article, and forwarding communications of the finder of the article to the owner where the finder may have provided no more than the ID and the communication to the virtual locale.
[0010] In accordance with another aspect of the invention, there is a system for facilitating communication between a finder of an article and an owner of the article which includes a virtual locale, a database for storing an association between owner contact information and a unique ID, and a module for forwarding finder communications to the owner where the finder provides as little information as the communication and the unique ID to the virtual locale.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1A , 1 B, 1 E, 1 F, 1 G, 1 H, 1 I, 1 J, 1 K, 1 L, 1 M, 1 N, 10 , 1 P, 1 Q, 1 R, 1 S, 1 U, 1 V, 1 X, 1 Y, and 1 Z depict steps of a method in accordance with a preferred non-limiting embodiment of the invention;
[0012] FIGS. 2A and 2B depict examples of tags with associated IDs and reference addresses that could be employed in accordance with embodiments of the invention;
[0013] FIG. 3 depicts a main menu that could be employed in accordance with embodiments of the invention;
[0014] FIG. 4 depicts an owner main menu that could be employed in accordance with embodiments of the invention;
[0015] FIG. 5 depicts an ID registration screen that could be employed in accordance with embodiments of the invention.
[0016] FIG. 6 depicts an open case screen that could be employed in accordance with embodiments of the invention;
[0017] FIG. 7 depicts a new user screen that could be employed in accordance with embodiments of the invention;
[0018] FIG. 8 depicts a contact information screen that could be employed in accordance with embodiments of the invention;
[0019] FIG. 9 depicts a view/edit tag screen that could be employed in accordance with embodiments of the invention;
[0020] FIG. 10 depicts a finder main menu that could be employed in accordance with embodiments of the invention;
[0021] FIG. 11 depicts a send message menu that could be employed in accordance with embodiments of the invention;
[0022] FIG. 12 depicts a short one way message entry screen that could be employed in accordance with embodiments of the invention;
[0023] FIGS. 13A and 13B depict anonymously addressed e-mails that could be employed in accordance with embodiments of the invention; and
[0024] FIG. 14 depicts an instant message that could be sent in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In the following detailed description, reference is made to various specific embodiments in which the invention may be practiced. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be employed, and that structural and logical changes may be made without departing from the spirit or scope of the present invention.
[0026] The present invention provides systems and methods that allow a person, such as a finder of a lost or misplaced object, to anonymously communicate with another, such as the owner of the object. The systems and methods can be useful in facilitating the return of the object to its owner.
[0027] In an aspect of the invention, an “owner,” which can be an individual or entity wishing to protect portable personal property, is provided with specially prepared tags. With reference to FIGS. 2A and 2B , such tags can be of any size or shape or type, such as a printed adhesive label 200 , a sew-on patch (not pictured), a plastic key-ring tag 250 with a hole for a key ring or keychain 230 , or even an electronic tag (e.g. an RFID) (not pictured). Two common features of the tags of the present invention are a unique identifying feature such as an ID (e.g., a string of alphanumeric characters) 210 and a reference to a specific website or other unique virtual locale (e.g., a text messaging number, an SMS number, or an instant messaging screenname) 220 . The ID 210 may be printed and/or electronically stored on or within the tag. As with the ID, the reference to the specific website or other virtual locale 220 may also be printed and/or electronically stored.
[0028] As used in some of the figures, a tag is referred to as a zTag and an ID is referred to as a zID.
[0029] In an embodiment, the owner would then affix tags 200 or 250 to any portable possession which she desires to be easily returned to her if lost or otherwise separated from her. Such objects and possessions might include an attaché case, a ring of keys, a portable music player with a large collection of music, a digital camera with irreplaceable family photos, a cell phone, and the like.
[0030] Having been provided with tags and having affixed the tags to various possessions, the owner can then register the tag IDs and the owner's contact information on a centralized and network accessible database according to the present invention.
[0031] With reference to FIG. 1A , a user, in this case, an owner, accesses a browser or client capable device, starting its operating system, ref. 1 , if necessary. Then the user navigates to the server, ref. 2 , using the browser or client capable device and receives a main menu, ref. 3 .
[0032] With reference to FIGS. 3 and 1A , the server displays a menu 300 , ref. 4 , which in a preferred embodiment has a menu button for requesting the owner menu 310 , a menu button for requesting the finder menu 320 , and a data field for entering an ID of a found object 330 .
[0033] In an exemplary embodiment, a user who is new to the system can select the option 340 “sign-up and register,” ref. 13 ( FIG. 1B ), from the main menu. When this option is selected, a data entry screen is displayed. With reference to FIG. 7 , the data entry screen may optionally be preceded by a “bot-killer” registration screen 700 , in which the user enters initial credentials such as an email address 710 and password 720 , and additionally enters a Verification Code in a field 730 , where the Verification Code 740 is displayed in a optically obfuscated manner so that an automated “bot” cannot register as a user. The registration screen may optionally include a consent to usage terms feature 750 . Following this optional bot-killer data entry screen, with reference to FIG. 8 , the screen 800 may include fields for adding and editing data such as the user's name 840 and various types of contact info, ref. 33 . Generally, in addition to a password, the only other required field is an unambiguous contact field entry, such as the user's email address 850 . If a user selects “save changes” or “add the new user,” ref. 34 , the entered data is validated, ref. 35 , and the new user is added to the database, ref. 37 . Then the main owner screen is displayed, ref. 7 ( FIG. 1B ). Should the entered email address already exist in the database, the user is alerted to the error, ref. 36 , and this procedure is restarted, ref. 33 . In a preferred embodiment, there is an option that the user can always select, ref. 38 , to return to the main owner menu, ref. 7 , without entering any information.
[0034] When a user selects the owner option 310 , ref. 4 , the main owner menu 400 ( FIG. 4 ) is displayed, ref. 7 ( FIG. 1B ). The owner menu offers owner related choices, including going back to the Main Menu, ref. 8 .
[0035] Should a user select Owner Log On, ref. 9 , an Owner Log On screen is displayed (not shown) and the user is prompted for their email address and password, ref. 62 ( FIG. 1K ). The system verifies these credentials against those in a database to determine whether they match a valid user, ref. 63 . If there is a match, a flag is set to indicate that the owner is logged on for this session, ref. 64 , and the owner's unique user id, herein userid, is placed in memory for future reference. If there is no match, an appropriate error message is displayed to the user, ref. 65 . Once these steps are completed, the main owner menu is displayed, ref. 7 ( FIG. 1B ).
[0036] An owner wishing to associate an ID with his or her contact information must register the ID with the database. In an exemplary embodiment, the owner/user selects the “add a zTag” menu item 410 ( FIG. 4 ), ref. 10 , and is prompted, ref. 15 ( FIG. 1E ), with a screen 500 as shown in FIG. 5 containing fields for entry of the relevant information for that tag such as its ID 510 and a description 520 of the associated object or possession. However, before entering this part of the program, subroutine D is called to validate that the “owner logged on” flag is set to true, ref. 39 ( FIG. 1L ), and return, ref. 40 , to the calling step in the application if so, or display an appropriate message, ref. 41 , and return to the main owner menu, ref. 7 ( FIG. 1B ), if not. Once the user supplies the information and selects “add item” 530 , ref. 16 ( FIG. 1E ), the server confirms that the data is in the valid format, ref. 17 , and that the user has entered a valid and available ID, ref. 19 . Any error in this process is displayed to the user, ref. 18 and the screen 500 may be displayed, ref. 15 . If there are no errors, the database is updated with the tag information and the database record is associated with the user, ref. 20 . Control then passes to the main owner menu 500 , ref. 7 . There, the user may opt, ref. 21 , to return to the main owner menu, ref. 7 , without entering any information.
[0037] In the illustrated embodiment, when an owner wishes to see open cases, where an open case is defined as an instance of an open line of communication with a finder of an owner's tagged item, they select the menu item “view open cases” 450 , ( FIG. 4 ), ref. 11 ( FIG. 1B ). Before displaying the view open cases screen, subroutine D is executed in a manner similar to that earlier described with regard to subroutine D. The database is then queried for any open cases where the user's userid is listed as the owner. Retrieved records are used to create a list 600 ( FIG. 6 ), which is displayed to the user, where each line is related to an open case, and includes information from that particular case. For example, a list of open cases might include an ID of a tagged object 610 and a description of the tagged object 625 . Links may be associated with each case-related line which enable a user to close the case 650 or communicate with the finder of that case 620 . There are numerous options throughout this menu, and its submenus, so that the user can always select an option, ref. 31 ( FIG. 1F ), to return to the main owner menu without entering any information. If a user selects “close case,” ref. 25 , the case is marked as closed in the database, ref. 26 , and the open case screen 600 is updated, ref. 22 . Should the user select to contact the finder of a particular case, ref. 27 , they are prompted and given a field to type their email message, ref. 28 . In one embodiment, a finder's anonymous email address is displayed with a reminder that the user can email the finder using their own email program. Once the user selects “send message,” ref. 29 , the finder's real email address is used (yet never displayed to the user) to send an email, ref. 30 . This part of the program is then directed to restart, ref. 22 .
[0038] Existing users can choose to edit their account settings, ref. 12 . Before displaying the account settings editing screens, subroutine D is run in a manner similar to that already described with regard to subroutine D. The database is queried for information associated with this user through use of a userid. In one embodiment, the user information will be displayed in editable fields, ref. 45 . With reference to FIG. 8 , such fields may include fields for the user's name 810 , addresses, password 860 , Instant Message Handles 810 , 820 , and 830 , phone numbers, and so on. The user may select to return, ref. 50 , to the main owner menu, ref. 7 , without entering any information. If the user selects “save changes,” ref. 40 , the system confirms that the new data are valid, ref. 47 , and if so, saves the record to the database, ref. 48 . Then the main owner window, ref. 7 , is then displayed to the user. If the validation fails, an appropriate message may be displayed to the user, ref. 49 , and the edit account settings screen is displayed, ref. 45 .
[0039] In an exemplary embodiment, a user who has tags already registered in the system may edit the data, ref. 14 , associated with them. Before entering this part of the program, subroutine D is executed in a manner similar to that previously described herein. Following verification of the “owner logged on” flag by subroutine D, the database is queried for all tags associated with a userid of the user, ref. 51 . With reference to FIGS. 1I and 9 , for each such tag in the database, an information line may be created, ref. 52 , containing the tag's associated information such as the tag ID 930 , the date it was registered, description 940 and so on. Also, two links may be created for each tag, the links respectively allowing a user to “edit” the information associated with the tag, or “delete” the associated tag record from the database. The list is then displayed 900 to the user, ref. 53 . There may also be included on this menu, ref. 60 , and its submenus, e.g., ref. 61 , an option for the user to select to return to the main owner menu, ref 7 , without entering any information. Should a user select a delete tag link 920 , ref. 54 , the tag record's description and owner userid are both cleared in the database, ref. 55 , making the ID available for later use. From this point, the list is refreshed beginning at ref. 51 . If a user opts to edit a tag 910 , ref. 57 , then an editable field may be displayed, ref. 58 , containing that tag's current description and operable to allow the user to edit the description in a manner similar to that depicted in FIG. 5 . Once the user chooses to save the new description, ref. 56 , the database entry for that tag is updated, ref. 59 . From this point, the list is refreshed beginning at ref. 51 .
[0040] Thus far, discussion has been made of how an owner of a tagged object can access and utilize a system in accordance with the present invention in order to supply and/or manage at least contact information and tag IDs. Another aspect of the invention involves finders. A finder is someone who has found an object, most likely lost, with an attached tag such as the exemplary tags depicted in FIGS. 2A and 2B . Such tags direct a finder to, for example, a website or other virtual locale.
[0041] In a preferred embodiment of the present invention, a tag attached to an object will direct a finder to access a website named thereon 220 . At such a website, the finder may select the finder option, ref. 5 , resulting in the display of the finder main menu, ref. 66 . The finder main menu provides selections related to finders. Additionally, the finder may opt to return to the main menu, ref. 67 .
[0042] According to one embodiment of the invention, a finder who is new to the system can select the option “new user,” ref. 70 . The program then creates and displays editable fields which may include fields for the user's name and various types of contact information, ref. 100 ( FIG. 10 ). Required information may include a password and an unambiguous contact information such as an email address. If a user selects to “add the new user,” ref. 101 , the system makes sure that the supplied information is valid, ref. 102 , and then adds the new user data to the database, ref. 103 . At this point, the main finder window is displayed, ref. 66 ( FIG. 1J ). Should the email address already exist in the database, the user is alerted to the error, ref. 104 , and the display is refreshed, starting at ref. 100 . Additionally, there may be an option, ref. 105 , for the user to select to return to the main owner menu, ref. 66 , without entering any information.
[0043] Should a user select “Finder Log On,” ref. 68 , they are prompted for credentials such as their email address and a password, ref. 73 ( FIG. 1M ). The database is then queried for a match to the entered credentials, ref. 74 . If a match is found, then a flag is set to indicate that the finder is logged on for this session, ref. 75 , and the finder's unique user id, herein userid, is placed in memory for future reference. If no match is found, an error message is displayed to let the user know that they are not logged on, ref. 76 . In either case, the main finder menu 1000 ( FIG. 10 ) is displayed, ref. 66 .
[0044] With reference to FIG. 10 , in accordance with an exemplary embodiment of the present invention, when a finder wishes to see open cases, where an open case is defined as an instance of an open line of communication between a finder and an owner with regard to an owner's tag, the finder selects “view open cases” 1010 , ref. 69 . Before displaying open cases, however, subroutine L, as shown in FIG. 1L , is called. This subroutine checks that the finder logged on flag is set to true, ref. 42 , and returns control to the application at the point of call to this subroutine, ref. 43 . If it is not, a suitable message is displayed to the user, ref. 44 , and the main finder menu is displayed, ref. 66 . If subroutine L verified the finder logged on flag, then the database is queried for open cases, where a finder's userid is listed as the finder, ref. 77 ( FIG. 1N ). The retrieved data is used to create a list, ref. 78 , which is displayed to the user, ref. 79 . The list may contain one line for each open case associated with the userid. A line may include two links which, respectively, enable the user to close the case, or communicate with the owner of that case. There may be numerous options throughout this menu, and its submenus, including options, refs. 86 and 87 , to return to the main finder menu, ref. 66 , without entering any information. The user can close the case, ref. 80 , which marks it as closed in the database, ref. 81 , and then refreshes the list, starting at ref. 77 . Should the user select to contact the owner of a particular case, ref. 82 , a display is created with a data entry field in which the user may enter an email message for the associated owner, ref. 83 . In a preferred embodiment, the display includes an anonymous email address, created in accordance with the invention, which corresponds to the owner's actual email address. The display also includes a reminder to the finder that they may optionally use the anonymous email address to contact the owner using the finder's own email software. Once the user selects “send message,” ref. 84 , the message is sent to the owner's real email address, ref. 85 . That email address is never displayed to the finder. The display is then refreshed with the open case list by beginning again at ref. 77 .
[0045] Existing users can chose to edit their account settings 1020 , ref. 72 . Before displaying the edit account settings screen, subroutine L ( FIG. 1L ) is called to validate that the finder logged on flag is set to true in a manner similar to that already described with regard to subroutine L. If the logged on flag is properly validated by subroutine L, the database is queried using the previously stored userid for information associated with this user's account settings such as name, addresses, password, email address, and so on. This information is displayed to the user in editable fields, allowing the user to make changes, ref. 115 ( FIG. 1Q ). Preferably, there is an option that the user may select, ref. 120 , to return to the main finder menu, ref 66 , without entering or saving any information. Once the user selects save changes, ref. 116 , the system confirms that the data are valid, ref. 117 , and if so, saves the changes to the database, ref 118 , and displays the main finder window, ref. 66 . If invalid data were found, appropriate error messages are displayed to the user, ref. 119 , and the display is refreshed from ref. 115 .
[0046] In one embodiment a user may choose to search for an ID number, ref. 71 . With reference to FIG. 11 , upon such a selection, a display 1100 containing a blank field 1110 will prompt the user to enter a search ID number, ref. 106 . Preferably, there are options on this menu (not shown in FIG. 11 ), ref. 114 , and its submenus, ref. 113 , allowing a user to select to return to the main finder menu, ref. 66 , without entering any information. Should the user enter an ID and click find, ref. 107 , the database is queried to see if the ID is valid and in use, ref. 108 . In one embodiment of the invention, entry to this part of the program, ref. 108 , may also occur from the main menu, where an ID field may exist for fast access to the search function. Should the ID not be a valid number for any reason, then the user is alerted, ref. 109 , and the finder menu, ref. 66 , is displayed. If the ID is valid, the description associated with it is shown, ref. 110 , to the user. In a preferred embodiment, two new choices may be displayed, allowing the finder to send a quick one-way anonymous message to the owner or to open up a new case and communicate using anonymous emails addresses.
[0047] With reference to FIG. 12 , if the finder chooses to send a quick one-way message, ref. 111 , the user is then prompted to enter an email message into a provided field 1210 , ref. 129 . Optional text on the display may advise the finder that the quick one-way message is indeed one-way and that the owner will not be able to reply to the finder/sender. Preferably, there is an option, ref. 134 , to return to the main finder menu, ref. 66 , without entering any information. Once the user selects “send message,” ref. 130 , the message is directed to the real email address of the owner associated with the entered ID, ref. 131 . The owner's real email address is used but never displayed to the finder. If the owner has any other contact information entered, ref. 132 , for example, Instant Message handles, then the message is also sent out via those systems, ref. 133 . The program then returns to the finder menu, ref. 66 .
[0048] In one embodiment, a finder may choose to open a new case, ref. 112 , for a tag ID associated with a found object. Prior to displaying a new case screen, subroutine L ( FIG. 1L ) is executed to validate the user logged on flag in a manner previously described for subroutine L. A new database record is created for this case, ref. 121 , and two anonymous email addresses are generated. In an exemplary embodiment, one email address begins with “Owner-,” ref. 122 , and the other with “Finder-,” ref. 123 . The generated email addresses may include a domain associated with the virtual locale. As an example, if the case involves ID 277899028 and the virtual locale is associated with www.zReturn.com, then the generated addresses could be Owner-277899028@zReturn.com and Finder-277899028@zReturn.com. The real email addresses for both the finder and the owner may be stored in the case record, ref. 124 . The finder is then provided a data entry field and prompted to type a message to the owner, ref. 125 . Optionally, the owner's anonymous email address may be displayed to the finder with a reminder that the finder may email the owner using the finder's own email program. Once the user selects “send email,” ref. 126 , the message in the data entry field is directed to the owner's real email address, ref. 127 , and; the real email address is never displayed to the user. The program can then return to the finder menu, ref. 66 . Preferably, there is an option, ref. 128 , on the new case screen allowing a user to return to the main finder menu, ref. 66 , without entering any information.
[0049] With reference to FIG. 1Z , in a preferred embodiment, a server periodically executes a program to check for incoming email, ref. 88 , being delivered to a domain associated with the virtual locale. If there are no emails, the program halts, ref. 89 a . If an email has arrived, its “To” email address is checked for “Owner-,” ref. 90 , “Finder-,” ref. 91 , and “Alert-,” ref 91 a , to determine whether the email is addressed with an anonymized email address. If not, then the email is forwarded to any other account setup for internal use on the server, ref. 92 , and the program continues checking for new emails, ref. 88 . If the “To” email address begins with “Alert-”, then the email is passed off to the server application that handles the Multi-protocol Messaging Translator, ref. 165 ( FIG. 1X ). Otherwise, a case number associated with the “To” email address is determined and the database is queried for a record of an associated open case, ref 93 . If no such record exists, ref. 94 , then an auto-generated reply is sent to the sending email address, ref. 98 , explaining that no such record exists, and the program starts checking for new emails, ref. 88 , again. If a record does exist, the “From” email address is checked versus the email address contained in the record, ref. 95 . If the “From” email address is not the same as the record, then a reply is sent to the sender explaining that anonymous emails must be sent from the same email address registered in the case record, ref. 99 , and the program starts checking for new emails, ref. 88 , again. With reference to examples in FIGS. 13A and 13B , once email addresses have been confirmed, then the “To” anonymous email address 1320 is swapped with a real email address 1340 as per the record and the real “From” email address 1310 is replaced with an anonymous address 1330 from the record, ref. 96 . Then, the email is forwarded to the new “To” email address, ref. 97 . The receiving user's id record is checked for associated alert contact information such as AOL Instant Messenger, Yahoo Messenger, and/or Microsoft Messenger Handles and/or a cell phone text messaging address. For any of those that the user provided, the email is also forwarded to those systems, refs. 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , and 174 ( FIG. 1Y ). Then the program starts checking for new emails, ref. 88 , again.
[0050] With reference to FIG. 1X , in one embodiment, a program run by a server checks periodically for incoming messages from multiple messaging protocols such as AOL, Yahoo, and MSN Text Messaging, ref. 135 . If there are no incoming messages, ref. 136 , the program halts, ref. 137 . If there is a message, the first word of the message is isolated, ref. 138 , and checked against the database to see if it is a valid ID. If it is not a valid ID, or there is only one word in the message, then a simple instruction message, such as “How to properly use the system” is sent back as a reply to the sender, ref. 139 , and the program goes to check for other new messages.
[0051] If the ID is valid, the messaging screenname that sent this message is checked, ref 140 , against all forms of messaging names and protocols associated with the owner who registered the ID number contained in the message. If it is determined that this message came from the owner of the ID to which the message refers, then control is passed over to ref. 161 . If none of the owner associated names and protocols match the sender of the message, then a messaging database is queried to match up the ID and the message's screenname and protocol, ref 141 . If no record is found, then a record is created, linking the ID, the screenname, and the protocol, refs. 142 , 143 , and 144 .
[0052] Continuing with the exemplary embodiment for handling inbound Instant Messages, the inbound message will be directed to the owner's designated IM addresses. With reference to FIG. 14 , for each existing form of alert that the owner registered, e.g. AOL, MSN, Yahoo, cell phone text messaging, and so on, the software will make a new message that may optionally include an introduction concerning the nature of the message 1410 and how to properly reply to it. The message will include the message sent by the sender 1420 . The message will be sent to each of these messaging options registered by the owner, refs. 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , and 158 ( FIG. 1U ). A new message, as described above, may optionally be sent to the owner's email address. The “From” email address may be of a form similar to “Alert-XXX@zReturn.com,” where XXX is the ID number. The software application then looks for more incoming messages, ref. 135 ( FIG. 1X ).
[0053] Finally, if it is determined that the inbound message originated from an owner of an ID to which the inbound message refers, then the application looks in the alert database for the record created by the sender of the original message, refs. 141 , 142 , 143 , and 144 . If no record can be found the application halts, refs. 161 , 161 a . Otherwise, the screenname and protocol are pulled from the found record, and a new message is created which may optionally include an introduction on what this message is, and how to properly reply to it. The message includes the message sent by the sender. The new message is then sent to the screenname and platform from the record in the alert database, refs. 161 b , 162 , 163 , and the program continues to look for more messages, ref. 135 .
[0054] The foregoing disclosure of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art given the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
[0055] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.
[0056] Furthermore, a person skilled in the art will recognize that some aspects of the present invention, described with reference to a sequence of condition checks, may be easily implemented with an event driven code design.
[0057] Aspects of the described system and method may be implemented in a programming language such as the Perl programming language in conjunction with the Apache open source web server software and the MySQL open source relational database running under the Linux operating system. Additionally, those of skill in the art are aware of open source modules available to aid in implementing aspects of the present invention. For example, the Perl module Net-Oscar is available from cpan.org and is operable to interface with instant messaging systems such as AOL instant messenger and ICQ. However, other programming languages, operating systems, and database systems are adaptable to the present invention and may also be used. | A method and system of facilitating communication between a finder of an article and an owner of the article including providing a unique ID to the owner and allowing the owner to register an association between the ID and owner contact information, allowing the owner to associate the ID and a virtual locale with the article, and forwarding communications of the finder of the article to the owner where the finder may provide no more information to the virtual locale than the ID and the communication. | 7 |
FIELD OF THE INVENTION
The present invention relates to method and apparatus for making artificial snow.
BACKGROUND OF THE INVENTION
In general, artificial snow-making involves atomizing a spray of water with a jet of air to create a plume of very fine water droplets which nucleate and form snow as the plume drops to earth under freezing temperature conditions.
The present invention is a modification of a known snow-making system patented and commercialized by Herman K. Dupre.
In U.S. Pat. No. 3,706,414, issued Dec. 19, 1972, Dupre taught bringing pressurized air and water through separate flowlines to the bases of hillside towers positioned along a ski trail. The air and water were introduced at controlled rates into a mixing chamber positioned at the foot of each tower. The mixture then flowed upwardly through a conduit forming the tower and was discharged through nozzles. Inherent in this system were the following features:
some atomization or reduction in water droplet size due to mixing with air;
rapid cooling of the water when the pressurized air was released into the freezing atmosphere and it expanded;
the provision of dwell time as the plume fell to earth from an elevated starting point; and
some control over the air/water ratio, with a view to optimizing it.
In a subsequent U.S. Pat. No. 3,822,825 issued Jul. 9, 1974, Dupre taught bringing the water and air separately up the tower in inner and outer, concentric, spaced apart conduits. The air flowed through the inner conduit passageway and the water through the outer annular passageway formed between the conduits. As a result, the water stream functioned to insulate the air stream. There is moisture in the air and it will condense and freeze to form "rime ice" if the atmospheric temperature is low enough and the air stream becomes chilled sufficiently. In another aspect taught, the air was delivered to a tee and released into the atmosphere through a pair of diametrically opposed orifices. These orifices were holes drilled through the wall of the outer conduit, to communicate with the bore of the tee. Dupre taught that the air outlet should be flush with the outer surface of the outer conduit, to avoid cooling of the air while passing through the orifice with consequent formation of rime ice, which could block the orifice. Dupre further taught discharging the water through a nozzle angled at 45° relative to the long axis of the conduit and having a shaped orifice adapted to deliver a substantially flat and V-shaped spray. His air orifice was positioned just above the water nozzle and was angled at about 90° relative to the long axis of the conduit. The term "associated pair" is used herein to denote a pair of outlets arranged so that the air jet and water spray which they produce intersect with the result that the air atomizes the water and a nucleated plume is produced. The air orifice was positioned to discharge its jet into the throat of the water spray. In another feature, Dupre taught mounting diametrically opposed associated pairs of air orifices and water nozzles, each pair being at a common elevation. This arrangement is referred to as providing a "bank" of associated pairs of air orifices and water nozzles. Inherent in this design were the following concepts:
bringing the air and water through separate conduits to the discharge elevation;
using the water stream to insulate the air stream until it was discharged to the atmosphere;
associating the air orifice and water nozzle in a spatial arrangement such that the air jet would converge with and contact the central portion or throat of the water spray, to cause atomization; and
utilizing a bank of air and water outlets.
In a still more recent patent, U.S. Pat. No. 5,004,151 issued Apr. 2, 1991, Dupre addressed the need to increase snow production capacity. A discrete snow gun was attached to the upper end of a conduit tower secured to a vertical post. The snow gun had an associated pair of water and air outlets, comprising a water nozzle and an air orifice. A second water nozzle was inwardly spaced along the gun from the outer water nozzle of the associated pair. The second water nozzle was inclined at a more acute angle than the first water nozzle, so that the water spray of the second nozzle would converge into and contact the plume produced by the associated pair. In this way, the available single jet of air was used to atomize the two sprays of water.
The Dupre system has won commercial success. The commercial version incorporates the features described above. It can be described more specifically as follows:
a snow gun is mounted on a boom or tower having universal movement;
the gun has two banks of V-jet water nozzles spaced along the long axis of the gun;
a single bank of air orifices is associated with the outer water bank;
the inner bank of water nozzles directs its sprays into the nucleated sprays of the outer bank; and
coaxial water and air conduits form the body of the gun and provide an annular outer passageway for supplying pressurized water to the two banks of water nozzles and an insulated inner passageway for supplying pressurized air to the single bank of air orifices.
While the Dupre system has been an admirable success, there are still certain shortcomings which could be improved upon. More particularly:
the Dupre system is not capable of producing quality snow at freezing temperatures milder than -6° C. using a water volume that would be commercially viable. The literature indicates that the system can only operate at -6° C. with a low humidity of about 60%. There are many ski areas that have a significant number of days during the season when the temperature is milder than -6° C. There is therefore a need to develop a system which can operate at milder freezing temperatures;
it is always desirable to increase the snow-making capacity of the snow gun;
there is a need to provide a snow gun which can be used without air when the temperature is cold; and
there is a need to provide a flanged snow gun that is disconnectable from the tower, for easy removal to permit service to the snow gun and to permit replacement with a snow gun having upgraded components.
It is an objective of the present invention to provide a snow gun which satisfies these needs.
By way of further background, it is pointed out that the V-jet nozzles used in the art are classified by the designations 5020, 5040 and 5060. A 5020 nozzle produces a flat, V-shaped spray having an angularity of about 50° and discharges 2 U.S. gpm of water, when operated at 40 psi. A 5040 nozzle produces a similar spray at 4 U.S. gpm at 40 psi. And the 5060 nozzle produces a similar spray at 6 U.S. gpm at 40 psi. If the pressure is increased, all of the nozzles will deliver more water at a wider angle.
SUMMARY OF THE INVENTION
In one feature of the present invention, an air nozzle which produces a substantially flat and V-shaped air jet is associated with a water nozzle which produces a substantially flat and V-shaped water spray, in the context of a snow gun, the two nozzles being specially arranged or coupled so that the air jet and water spray converge and intersect along a line where their widths are substantially equal. The phrase "coupled paid" is used to denote an air nozzle and water nozzle pair as described in the previous sentence. A coupled pair is a specific embodiment of an associated pair.
When a snow gun having a coupled pair of air and water outlets, as described is operated, a remarkably efficient and complete atomization of the water into very fine droplets is achieved. This degree of atomization has enabled the gun to produce snow at -11/2° C. at 85% humidity.
In another feature, a plurality of banks of associated pairs of air and water outlets are spaced along the length of a snow gun. The associated pairs are oriented so that the plumes which they produce do not significantly converge and intersect. For example, the water nozzles of one bank can be similarly angled relative to those of the next bank so that the plumes travel substantially in parallel. By implementing this feature, efficient and complete nucleation of multiple water sprays is obtained while increasing the snow-making capacity of the gun relative to the prior art.
The air nozzle preferably should be embedded in the wall structure forming the air and water conduits of the snow gun, to minimize the formation of rime ice.
To provide more than one bank of embedded air nozzles has required the development of a unique conduit structure and fabrication process. This has been achieved and is described hereunder.
As a result, it is now possible to provide in a snow gun multiple coupled pairs of air and water outlets along the length of the gun, each involving V-jet nozzles for both air and water. This has meant that the snow-making capacity of the gun can be increased by using a plurality of banks of coupled pairs and each V-shaped water spray is individually atomized by its own V-shaped air jet. The nozzles of the water banks are angled so that their produced plumes are non-converging; thus one water nozzle does not significantly increase the water droplet size of another.
By providing air and water outlets that each incorporate V-jet nozzles, one can now provide a 5020 nozzle in one outlet and a 5040 nozzle in the other outlet. One then has the option of supplying each of water or air to either the 5020 nozzle or the 5040 nozzle, by changing over the fluid supply lines at the base of the tower. Thus, in cold weather when the air/water ratio can be low, one can supply the water through the 5040 nozzle and the air through the 5020 nozzle, with high snow output. In milder weather, when the air/water ratio needs to be higher, one can supply the water through the 5020 nozzle and the air through the 5040 nozzle--the snow output is diminished but the increased atomization due to higher energy input results in finer water droplets being produced; these finer droplets have a better chance of forming snow at the mild conditions.
If desired, at cold temperatures the air can be shut right off and water sprayed through the 5020 nozzle will make snow at an adequate rate without the cost of air compression and without coping with air nozzle freeze up problems. At very cold temperatures, both nozzles can be supplied with water alone.
In summary so far then, the attributes of a system incorporating features of the invention can include:
improved atomization, which leads to finer droplet size and the ability to nucleate and form snow at freezing temperatures milder than -6° C.;
more complete atomization, as the entire width of the water spray preferably is contacted by the air jet;
increased snow-making capacity, as more water banks can now be incorporated into a single snow gun and their sprays can be independently nucleated;
versatility, in that nozzles of different capacity can be used in a coupled pair and the nature of the fluid discharge of these nozzles can be switched from ground; and
the option to terminate air supply during cold weather conditions.
Broadly stated, in one aspect the invention is embodied in a snow gun for making artificial snow, comprising: an inner conduit having a wall forming a first passageway, extending longitudinally of the gun, for delivering a stream of pressurized air; an outer conduit having a wall combining with the inner conduit to form a second passageway, also extending longitudinally of the gun, for delivering a stream of pressurized water; the first passageway extending through the second passageway; a water nozzle connected with the outer conduit and communicating with the second passageway for the discharge of water therefrom, said water nozzle having an orifice operative to produce a substantially flat and V-shaped water spray; an air nozzle connected with the inner conduit and communicating with the first passageway for the discharge of air therefrom, said air nozzle having an orifice operative to produce a substantially flat and V-shaped air jet; the air nozzle being associated with the water nozzle as a coupled pair so that the water spray and the air jet produced converge and intersect along a line where their widths are substantially equal.
The foregoing paragraph states the snow gun in the context of the way that it will be operated for at least part of the time--that is, with air passing through the core passageway and water through the outer passageway. However, as previously outlined, it is contemplated to be within the scope of the invention that the streams can be reversed or only water alone will be flowed through both passageways.
In still another aspect, the invention comprises providing a flanged connection connecting the lower end of the gun to the upper end of the tower, said connection forming dual sealed openings for connecting the air and water passageways of the tower and gun, so that the streams may pass through the connection without leakage.
In another aspect, the invention is embodied in a method for making snow at freezing temperatures, comprising: supplying water under pressure to a water nozzle forming part of a snow gun elevated above ground and discharging the water from the nozzle in the form of a substantially flat and V-shaped spray; simultaneously supplying air under pressure to an air nozzle forming part of the snow gun and discharging the air from the nozzle in the form of a substantially flat and V-shaped jet; and directing the nozzles so that the spray and jet converge and intersect along a line where their widths are substantially equal.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a snow gun mounted on the end of a tower;
FIG. 2 is a side elevation, partly in section, showing the base, boom and lift assembly of the tower;
FIG. 3 is a cross-sectional side view of the snow gun;
FIG. 4 is a top view, sectioned along the line A--A of FIG. 3, showing the intersecting, flat, V-shaped air jet and water spray of a coupled pairing of nozzles;
FIG. 5 is a plan view of a thick-walled ring, sectioned along the line B--B of FIG. 3;
FIG. 6 is an expanded, partly sectional side view of the outer coupled banks of air and water nozzles of a snow gun having a blanked end;
FIG. 7 is a side sectional view showing the nozzled end cap of FIG. 3;
FIG. 8 is a side sectional view showing the end cap of FIG. 7, taken along a plane at 180° relative to that of FIG. 7;
FIG. 9 is a side sectional view showing the flanged connection joining the snow gun with the tower;
FIGS. 10A-10K show the fabrication sequence used in constructing the snow gun with welds;
FIG. 11 is a sectional side view showing the two bank snow gun used to provide the data of Example I; and
FIG. 12 is a sectional side view of part of the tower, showing a bleed valve for bleeding water into the air stream.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Having reference to FIG. 1, a snow gun 1 is shown mounted on the upper end of a tower 2 by a flanged connection 3. The tower 2 comprises a boom 4. The boom 4 is rotatably and pivotally supported by a base 5.
The base 5 comprises a mounting pipe 6 and lifting assembly 7. Mounting pipe 6 slides over a post 8 which projects from the ground. The lifting assembly 7 enables raising and lowering of the boom 4 to change the elevation of the gun 1 and to access it.
As shown in FIG. 2, the lifting assembly 7 comprises a pivot pin 9 connected with the mounting pipe 6 and passing through boom 4. A threaded jacking screw 10 is pivotally connected at one end with the pivot pin 9. A collar 11 is mounted on the jacking screw 10, for axial movement therealong. A threaded nut 12 engages the jacking screw 10 and functions to bias the collar 11 therealong. A handwheel 13 is attached to the nut 12 for rotation thereof. Two compression members 14, 15 are pivotally connected at their inner ends to the collar 11. The first compression member 14 is pivotally connected at its outer end to the boom 4 by pivot pin 16 at a point above pivot pin 9. The second compression member 15 is connected at its outer end to the mounting pipe 6 by a pivot pin 17 located below pivot pin 9. Thus, as the collar 11 is advanced along the jacking screw 10 toward pivot pin 9, compression members 14, 15 approach co-linear alignment and raise the boom 4.
This arrangement provides significant mechanical advantage and minimizes the height of the base 5. The minimal height enables a single operator to lift the mounting pipe 6 upwardly to clear the post 8 for un-mounting and transportation of the assembly to another site.
The tower 2 comprises inner and outer, co-extensive, concentric tubes 18, 19. The inner tube 18 forms an internal passageway 20. An annular passageway 21 is formed between the tubes 18, 19. The inner tube 18 can be connected by a quick-connect coupling (not shown) with an air hose 22 for the supply of pressurized or compressed air to the inner passageway 20. The outer tube 19 can be connected by a quick-connect coupling (not shown) with a water hose 23 for the supply of pressurized water to the annular passageway 21.
As shown in FIG. 3, the snow gun 1 also comprises inner and outer, substantially co-extensive and concentric tubes 24, 25 forming an inner passageway 26 and outer annular passageway 27. The inner passageway 26 thus extends through the outer annular passageway 27 and is substantially co-extensive therewith. The tower and snow gun inner passageways 20, 26 are connected, as shown, as are the annular passageways 21, 27. (The inner passageways 20, 26 are hereafter referred to as the air passageways 20, 26 and the annular passageways 21, 27 are referred to as the water passageways 21, 27.)
The tower 2 is connected to the snow gun 1 by the flanged connection 3 having dual openings connecting the air passageways 20, 26 and water passageways 21, 27.
The flanged connection 3 is designed to resist the high pressure differential between the water passageway (typically at 700 psi) and the air passageway (typically at 110 psi) and prevent leakage therebetween. Having reference to FIG. 9, the tower 2 is provided with a flat-faced (or non-grooved) tower flange 28 forming bolt openings 29, water passageway opening means 30 and air passageway opening 31. The snow gun 1 is provided with a flat-faced gun flange 32 forming bolt openings 33, water passageway opening means 34 and an air passageway opening 35. A plate 36 is provided between the tower and gun flanges 28, 32. The plate 36 also forms bolt openings 37, water passageway opening means 38 and an air passageway opening 39, positioned to register with the corresponding openings and opening means of the tower and gun flanges, to provide continuity of the water and air passageways. Inner and outer concentric grooves 40, 41 are formed in the annular lands 200, 201 of the top and bottom faces of the plate 36, for receiving O-rings 42 for sealing the water and air passageways. The flanged connection 3 is completed by bolts 81 and nuts 80 securing together tower flange 28, plate 36 and gun flange 32.
Having reference to FIG. 3, the snow gun's inner tube 24 comprises, from its inner end outward, a series of sequentially repeated units 90, (see FIG. 10C) joined end to end. Each unit 90 comprises a relatively thin-walled tube segment 43 joined to a relatively thick-walled ring 44.
Each thick-walled ring 44 (see FIG. 5) forms a pair of radial, internally threaded openings 45 for receiving V-jet air nozzles 46. When screw-threaded into the openings 45, the air nozzles 46 are generally diametrically aligned and are each fully embedded or recessed in the wall of the ring 44. The ring 44 further forms an axial central opening 70 which forms part of the air passageway 26 and a plurality of relatively small, axial openings 47 which form part of the water passageway 27. The radial openings 45 and the air nozzles 46 contained therein communicate with the central opening 70, which forms part of the air passageway 26.
The snow gun's outer tube 25 comprises a series of sequentially repeated outer units 48 (see FIGS. 3, 10K). The innermost outer unit 48 joins the gun flange 32 and the innermost thick-walled ring 44. The remaining outer units segments 48 join adjacent pairs of thick-walled rings 44. Each outer unit 48 comprises a tube 92 and a tubular section formed of "doors" 60a/b, as described below.
Broadly stated, the inner and outer units 90, 48 combine to form a wall structure in which the air nozzles 46 are embedded and are insulated by the water moving through the structure.
Each outer unit 48 forms a pair of generally diametrically opposed openings 49 into which is welded an angularly directed, tubular dowel 50. Each dowel 50 is internally threaded. A V-jet water nozzle 51 is screwed into each dowel 50.
The dowels 50 are parallel so that the produced atomized plumes 52 do not converge or intersect.
At its outer end, the snow gun 2 is closed by a cap 53. The cap shown in FIGS. 3, 7 and 8 comprises an axially directed air nozzle 54 and a pair of angularly directed water nozzles 55. Alternatively, the cap 53 may simply blank off the end, as shown in FIG. 6.
The water and air nozzles 51, 46, 54, 55 all have shaped orifices 56 operative to produce a substantially flat and V-shaped spray or jet. Usually a 5020 air nozzle and 5040 water nozzle is the combination used.
An outer air nozzle and inner water nozzle are coupled or relatively positioned as shown in FIG. 3, so that the air jet 66 intercepts the water spray 57 along an imaginary line 58 where the widths of the jet and spray are substantially equal (see FIG. 4). A plume 52 of atomized water is produced.
The snow gun is constructed by welding in order to avoid leakage, given that water and air at relatively high pressure are passing therethrough.
A novel snow gun structure and welding fabrication sequence has been developed in order to enable the provision of a plurality of thick-walled rings 44. More particularly, as shown in FIGS. 10a-10k:
a thick-walled ring 44a is welded to a cap 53a at W1;
an inner tube segment 43a is seated in the inner end of the ring 44a and welded thereto at W2;
an outer tube 92a, having water nozzle dowels 50, is slid onto inner tube segment 43a and welded to ring 44a at W3 to produce unit 100;
in a separate second sequence, an inner tube segment 43b is welded to the inner end of a thick-walled ring 44b at W4--an outer tube 92b is slid onto segment 43b and welded thereto at W5 to produce unit 101;
in a separate third sequence, an inner tube segment 43c is welded to the inner end of a thick-walled ring 44c at W6--an outer tube 92c is slid onto segment 43c and welded thereto at W7 to produce unit 102;
unit 101 is slid onto unit 100 so that the inner end of inner tube segment 43a seats in the outer end of thick-walled ring 44b and is welded at W8;
similarly, unit 102 is slid onto unit 101 so that the inner end of inner tube segment 43b seats in the outer end of thick-walled ring 44c and is welded at W9;
pairs of doors 60a/b and 60b/c are then emplaced to close in the space between outer tube 92a and ring 44b and outer tube 92b and ring 44c respectively and are welded at W10-W17 as shown;
a collar 61 is slid onto the inner end of inner tube segment 43c and welded at W18;
in a separate fourth sequence, a frusto-conical tube 62 is welded to gun flange 32 at W19 to produce unit 103;
unit 103 is then slid onto inner tube segment 43c and is welded to outer tube 92c at W20; and
bottom collar 61 is welded to the gun flange 32 to complete the assembly of the snow gun.
The snow gun and its operation has been described in the context of air being supplied to the inner conduit passageway 26 and water being supplied to the outer annular passageway 27. This is the mode in which the gun will likely be operated most of the time. However, because V-jet nozzles are used in all of the fluid outlets, the air and water supply can be switched to passageway 27 and passageway 26 respectively, when appropriate.
As shown in FIGS. 2 and 12, a cross-mix needle valve 91 can be provided for bleeding a small stream of water (typically about 5 U.S. gpm) from the annular passage 21 into the inner tube passageway 20, for melting rime ice formed therein, when desirable. It has been found desirable to wet the air stream when temperatures drop below -8° C. (17° F.).
An example is now given to report on a test in which a snow gun in accordance with the invention was operated to produce snow at freezing temperatures milder than -6° C.
More particularly, a snow gun in accordance with FIG. 11 and having the dimensions set forth in Table I was built and tested.
TABLE I
gun length l=2.5 feet;
outer tube: 2" O.D. Schedule 80 aluminium pipe;
inner tube: 11/4" O.D. aluminum tubing having an I.D. of 1";
thick-walled ring having 1/4" O.D. water openings, a 1" central air opening and 1/4" NPT nozzle connections;
air nozzles--5020;
air nozzle angle--90° to gun axis;
water nozzles--5020;
angle of first bank of water nozzles--45°;
angle of second bank of water nozzles--45°;
distance a between first and second bank--8";
distance b between the center of each dowel opening and the center of each air nozzle--21/2".
When tested at the following conditions: -1.5° C., 85% humidity, 40 U.S. gpm at 600 psig, 100 cfm air at 100 psi; the gun produced good base snow.
The scope of protection to be accorded the invention is now set forth in the following claims. | In a snow gun, each of air and water are discharged through V-jet nozzles in the form of generally flat and V-shaped jets or sprays. The nozzles are spacially positioned and angled so that the air jet intersects the water spray along a line of intersection where they are of equal width. This provides efficient atomization of the water with the result that snow can be made at milder freezing temperature. In another aspect, a flanged connection, having dual sealed openings for passage therethrough of pressurized air and water streams, is provided to join the gun and its supporting tower. | 5 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional application No. 60/628,225, filed Nov. 17, 2004, incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a squeezable or thin set sauce resembling at least a portion of the properties of traditional cranberry sauce.
BACKGROUND OF THE INVENTION
[0003] Cranberry fruit sauce along with other jellied sauces and jams have a consistency that makes them set into a semi solid state that is then spoonable and or spreadable. These are important attributes for these products.
[0004] Conventional jellied sauces or jams have higher levels of fruit and may or may not use pectins or gums as thickening agents. Usually as the fruit levels are lowered thickeners are either added or increased to obtain the same sufficient rigid set.
[0005] The addition of pectins or gums may have sensory disadvantages (poor taste, slick or gummy mouth feel etc.). Once the gel in a typical jellied sauce is broken there may be weeping or syneresis.
[0006] Accordingly, a need has developed for a lower viscosity, thin set fruit sauce to increase flowability and allow squeezing as a means of dispensing or spreading, e.g., via a squeeze bottle.
BRIEF SUMMARY OF THE INVENTION
[0007] One aspect of the invention is directed to a unique blend of hydrocolloids that will provide a smooth, free flowing, squeezable sauce with very limited syneresis.
[0008] According to one embodiment of the invention, there is provided an edible composition containing (by weight based on the final composition consumed):
[0009] about 5-15% water
[0010] about 30-50% cranberry or fruit puree
[0011] about 30-50% sweetener
[0012] about 0.1-2.0% gel-forming hydrocolloids.
[0013] The above percentages (and all those described herein) may vary up to 5%-15% or more, depending on application. The resulting product may be in the form of a squeezable flowing sauce, e.g., cranberry sauce. The sweetener may take the form of corn syrup, or a sugar substitute having “low” or no calories.
[0014] According to another aspect of the invention, there is provided a method for making a squeezable sauce, comprising blending fruit and any sweetener components and heating; blending gel-forming hydrocolloids with water and/or dispersing gel-forming hydrocolloids in the sweetener; and cooking to evaporate water to a solids level of about 30-38 Brix.
[0015] In accordance with another aspect of the invention, there is provided a squeezable fruit sauce having low syneresis and made with gel-forming hydrocolloids. The sauce may include one or more of the following: a solids level of about 30-40 Brix; and/or a pH of about 2-4. Furthermore, the hydrocolloids may include one or more of the following: low methoxyl esterified pectin, esterified and amidated pectin and/or locust bean gum. Also, the sauce may be made with a sugarfree sweetener, or in the alternative, high fructose corn syrup or the like.
[0016] These and other aspects of the invention will be described in or apparent from the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Embodiments of the invention provide a thinner set cranberry or fruit sauce that is squeezable with low syneresis. The thin set sauce enables it to be dispensed using a squeeze bottle, which is convenient for consumers. The sauce is squeezable as a result of the increased flowability of the sauce, which can be achieved using, e.g., one or more hydrocolloids or other edible product thinners.
[0018] In one embodiment, the fruit sauce composition includes about 5-15% water, about 30-50% cranberry or fruit puree, about 30-50% sweetener and about 0.1-2.0% gel-forming hydrocolloids.
[0019] A process for the preparation of the fruit sauce includes blending fruit and any sweetener components and heating, blending gel-forming hydrocolloids with water and/or dispersing gel-forming hydrocolloids in the sweetener, and cooking to evaporate water to a solids level of about 30-38 Brix. The sauce is allowed to cool in order for the gel to set.
EXAMPLE
[0020] An example of the product and process of the invention will now be described to illustrate, but not to limit, the invention.
[0021] 10.6%—Water
[0022] 45%—Cranberry Puree
[0023] 36%—High fructose corn syrup
[0024] 5%—Sucrose
[0025] 1.4%—Cranberry concentrate
[0026] 0.67%—Pectin (esterified, amidated)
[0027] 0.14%—Locust bean gum
[0028] 0.11—Pectin (low methoxyl, esterified)
[0029] 0.07—Sodium Benzoate
[0030] Preparation Process
[0031] The ingredients of the above EXAMPLE were blended in 3 separate parts. Part one includes, and preferably consists of, the cranberry puree, cranberry concentrate, sucrose and sodium benzoate. Once blended, these ingredients are heated to 120-180° F., e.g., 150° F.
[0032] Part two includes, and preferably consists of, high fructose corn syrup and the Locust bean gum. Once blended they are added to part one in the cook kettle. However, it should be noted that it is not necessary to use high fructose corn syrup, as non-corn syrup substitutes are available with “low” or no calories.
[0033] Once part one and two are blended together they are brought to a temperature of 180-220° F., e.g., 200° F.
[0034] Part three includes, and preferably consists of, the water and hydrocolloids (e.g., one or more pectins and/or Locust bean gum). Once blended and inspected for lack of clumping, they are added to parts one and two in the cook kettle. The temperature is brought to about 195° F. and cooked to a Brix of 30-40, e.g., 34.0 to 35.0. The resulting pH should be about 2-4, and preferably about or exactly 2.9.
[0035] The product is then filled into a squeezable bottle or other container and cooled. A bottle appropriate for dispensing the squeezable fruit sauce is described in U.S. design patent no. 29/217,299, filed Nov. 16, 2004, incorporated herein by reference in its entirety.
[0036] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. For example, embodiments of the invention may also be applied to other cranberry or fruit blend sauces. | A squeezable fruit sauce containing less than 50% fruit. The sauce includes fruit and or fruit puree, water, sweetener, and a combination of pectins or thickeners. The ingredients combined to give a thin set sauce (30.0-40.0 Brix) with minor syneresis. | 0 |
FIELD OF THE INVENTION
This invention relates generally to a pedestrian railing used as a barrier or guard to protect pedestrians and bicyclists, and specifically, to an aluminum picket railing and the method of construction that reduces production costs significantly, while increasing structural strength.
DESCRIPTION OF RELATED ART
Guard railings are used near public conveyances such as walkways and bicycle paths to protect pedestrian traffic and cyclists for safety purposes. Although there are many variations in the construction of barriers, one type of guard railing uses a plurality of vertical, spaced apart aluminum pickets that are welded at top and bottom to horizontal or inclined bars. Metal posts are connected at spaced intervals that anchor the guard railing to the ground.
The disadvantages of welding numerous vertical aluminum pickets (at both ends) to top and bottom horizontal or inclined bars are loss of material strength and its expense. Although welding certainly provides very rigid construction and prevents removal or separation of the pickets from the railing itself, welding does weaken aluminum within one inch of the weld joint and is very costly and time consuming at the time of construction. The choice of aluminum is because of its ability to withstand harsh outdoor environments without rusting or severe oxidation. Aluminum is a difficult metal to weld.
The prior art shows a variety of different types of railing constructions. U.S. Pat. No. 4,346,872, issued Aug. 31, 1982 shows a balustrade construction that employs screw fasteners in construction. U.S. Pat. No. 2,590,929 issued Apr. 1, 1952 shows a railing that is pre-fabricated. U.S. Pat. No. 5,649,688 issued Jul. 22, 1997 shows railings with continuous spacers. U.S. Pat. No. 5,200,240 issued Apr. 6, 1993 shows an aluminum railing apparatus that uses screw fasteners. U.S. Pat. No. 4,586,697, issued May 6, 1986 shows another balustrade construction from extruded aluminum. U.S. Pat. No. 6,029,954 issued Feb. 29, 2000 shows a railing assembly that utilizes screw fasteners for construction. U.S. Pat. No. 6,041,486 issued Mar. 28, 2000 shows a method of assembling a fence.
When used by government for pedestrian walkways or bicycle paths, the barrier or guard railing should be rigidly constructed for use not only in protecting pedestrian traffic on walkways or cyclists on pathways but also to prevent theft or damage by people trying to deliberately damage public property. Thus, it is important that the railing be of a rigid, permanent type construction that cannot be readily disassembled, while at the same time being of reduced cost and complexity. This is especially true in the public arena where there is a requirement for large numbers of pedestrian and bicycle railings.
The present invention provides an improved pedestrian railing and method of construction that includes a rigid structure and method of manufacture that greatly reduces construction costs without reducing strength or rigidity of the entire structure. The improved pedestrian railing and method of construction is also easier to install and allows for replacement of pickets without the need for a welder.
SUMMARY OF THE INVENTION
A pedestrian railing and the method of construction comprising top and bottom parallel horizontal or inclined bars that each include a recessed, specially configured channel, disposed continuously along a predetermined segment of the railing bar exterior surface facing or projecting outwardly substantially radially. Each of the railing bars (top and bottom) has the same specially configured channel, viewed in cross-section.
Each pedestrian railing top and bottom bar external channel that protrudes from a peripheral section is substantially u-shaped in cross section. The channel walls parallel sides have coplanar, perpendicular, inwardly directed tabs, mid-length, separated at their ends by a space. The coplanar tabs divide the bar channel into two separate passageways. The railing bar channel is sized in width to receive (snugly) the end portion of a rectangular picket that fits into the recessed railing bar channel portions between the channel side walls. When the picket is in place, each picket end engages each bar channel and, abuts vertically the channel tabs that are used for holding each vertical picket in position in the vertical direction between top and bottom railing bars. The end face of each rectangular picket may be formed or cut at a ninety degree angle to the longitudinal axis of the picket for railings that are substantially positioned horizontally on flat ground but may be cut at an angle when used with top and bottom bars in a railing that is disposed inclined on a hill wherein the pickets are at relatively acute angles between the top and bottom rails. The end face of each picket in the inclined case can be cut at the appropriate angle, so that the angle between the top and bottom rail and the picket is equal to the end face angle cut on each of the picket ends to make each picket fit snugly within the channel.
A plurality of picket separating spacer plugs are used in the pedestrian railing construction to rigidly separate (at top and bottom) each vertical picket from an adjacent picket, and to hold the vertical pickets firmly in place. The spacer plugs are elongated, rigid, metal bars that are shaped in cross section to interlock and snap into each top and bottom railing bar channel.
A spacer plug has a cross-sectional shape and area (somewhat like an I-beam cross section) that is used to hold each bar picket in position laterally and is employed between each picket within the bar channel. Because of the spacer plug's unique cross-sectional shape, the spacer plug snaps snugly longitudinally into the top and bottom railing bar channels during the manufacture of the entire railing assembly when the pickets and spacer plugs are inserted. Once in place, each adjacent picket is separated rigidly by a separate snap-in spacer plug that is mounted in the top railing bar channel and the bottom railing bar channel. The spacer plug has end faces that are at a ninety degree angle to the longitudinal axis of the spacer plug when used in railings wherein the railing is mounted on flat ground representing the horizontal earth plane. In the situation where the entire railing is inclined at an angle relative to the earth's horizontal plane, such as a hill, the end face of each spacer plug may be angularly cut (not perpendicular) relative to the longitudinal axis of each spacer plug to accommodate the inclined angle so that the end face of each spacer plug fits snugly against the picket end portion in the bar channel that is used for the inclined environment. The cross-sectional shape of the space plug can be made to save the amount of metal used.
The ends of the pedestrian railing assembly are rigidly held together by vertical end bars that are welded to both the top and the bottom horizontal railing bars, once the pickets and spacer plugs are in place, adding tremendous rigidity to the entire rectangular structure. The last picket at each end of the entire guard railing structure is welded in place, top and bottom, to lock in the other pickets and spacer plugs.
A plurality of vertical support posts, which are preferably aluminum, are permanently attached to the ground in concrete pads and the top railing bar and the bottom railing bar. The posts are vertically disposed and placed apart as necessary and support the entire railing structure above the ground. The pickets can be arranged in a plumb line on an incline as are the support posts under certain hill conditions if required.
By using snap-in, rigid spacer plugs along with a plurality of pickets that all fit within top and bottom railing bar channels that project radially away from the periphery of the top bar and the bottom bar, the entire picket and railing bar assembly can be assembled and manufactured without welding each of the pickets individually to the top and bottom railing bars, except for the end pickets.
It is an object of this invention to provide an improved, aluminum pedestrian safety railing of increased strength and at reduced construction costs.
It is another object of this invention to provide an improved safety guard railing for use as a safety barrier along public walkways to protect pedestrian traffic and bicycle paths to protect cyclists that is non-complex to assemble, yet rigid in construction.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds.
It is to be understood that both the foregoing general description and the following detailed description are explanatory and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute part of the specification, illustrate embodiments of the present invention and together with the general description, serve to explain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a pedestrian and bicycle guard railing in accordance with the present invention, in a front elevational view.
FIG. 2 shows a side elevational view in cross section through A—A of FIG. 1 .
FIG. 3 shows a back elevational view partially cut away, of the railing post.
FIG. 4 shows a cutaway, exploded, perspective view of segments of the top and bottom bars, a picket, and top and bottom snap-in spacer plugs used in the present invention.
FIG. 5 a shows a side elevational view in cross section of a post connected to the top bar in the present invention.
FIG. 5 b shows a side elevational view in cross section of a post connected to the bottom bar in the present invention.
FIG. 6 shows the top end of a post in a perspective view without the top bar for connection of the present invention.
FIG. 7 shows a perspective view, partially cutaway, of the top bar, a picket and the spacer plug mounted in the top bar channel.
FIG. 8 a shows a side elevational view, partially cut away (with some pickets deliberately left out for clarity) mounted on an inclined hill.
FIG. 8 b is a side elevational view, partially cut away, showing a portion of the top rail as it is connected to at least two pickets and two spacer bars at an incline.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1 , the present invention is shown as a pedestrian or bicycle guard railing 10 made of aluminum that is used particularly for pedestrian walkways or bicycle paths as a guard or barrier. The railing 10 may be made in any desired length depending on the particular environment. The guard railing 10 is typically firmly mounted and connected to concrete base 21 which may be a walkway or retaining wall. The railing 10 is anchored by rigid aluminum posts 16 mounted to aluminum plates 20 that are bolted with anchor bolts 20 a into the concrete base 21 . This allows the railing 10 to be anchored to the ground in a vertical, upright position and held firmly in place. The anchor bolts 20 a (including anchor nuts) can be used to anchor the railing 10 into concrete base 21 with metal plate 20 that is rigidly attached to the railing post 16 described below. As shown in FIG. 1 , two vertical aluminum posts 16 are used to rigidly support the railing 10 in a vertical position and attach the railing 10 firmly to concrete 21 . The railing 10 is shown in FIG. 1 on level ground.
The railing 10 includes a top picket support bar 12 which is extruded aluminum and a bottom picket support bar 14 which is extruded aluminum, which can be made in indeterminate lengths or cut as desired and as explained herein. The top bar 12 and the bottom bar 14 are identical in cross-sectional shape, configuration and size. Top bar 12 and the bottom bar 14 each have identical cross-sectional areas and shapes that include a longitudinal passageway (see FIG. 4 ) disposed along a portion of the exterior surface (periphery) of each of the bars 12 and 14 . In fact, the top bar 12 is the same bar for use as bottom bar 14 . These bars 12 and 14 support a plurality of pickets 18 .
A plurality of pickets 18 are rigid aluminum bars that are vertically positioned and mounted between the upper bar 12 and the lower bar 14 , the picket ends within the longitudinal recessed channels of the upper bar 12 and the lower bar 14 . When the railing 10 is mounted on level ground, the pickets 18 are perpendicular to top rail 12 and bottom rail 14 and each picket end faces are cut perpendicular to the picket longitudinal axis.
At each end of the railing 10 , is a u-shaped curved, rigid aluminum bar 1120 that is welded at each end to top bar 12 and bottom bar 14 . The end bars 1120 give rigidity to the entire structure. The end pickets 18 e are welded at top and bottom at 18 w to hold the spacer plugs and other pickets 18 in place.
FIG. 2 , a side view through line A—A of FIG. 1 , shows one of at least two vertical posts 16 that supports the entire railing 10 above the ground and is anchored to the ground. The post 16 is connected (welded) to the upper bar 12 and the lower bar 14 . The posts 16 are typically welded to the upper bar 12 and the lower bar 14 for rigidity and are spaced at regular intervals along the entire railing 10 . The posts 16 act to support the entire structure vertically and anchor the railing 10 to concrete in the earth for permanency.
FIG. 3 shows the post 16 in relationship to upper bar 12 and lower bar 14 disposed on one side of the railing 10 on the opposite side as shown in FIG. 1 .
Referring now to FIG. 4 , the structural relationship between the upper bar 12 and the identical lower bar 14 with respect to vertical pickets 18 is shown. The railing 10 is constructed by placing a plurality of pickets 18 , which in this case happen to be rectangular in cross section, and sized in width “w” to fit as the same width of the bar channel 12 a to fit snugly within the elongated channel 12 a disposed in top bar 12 . The channel 12 a walls extend the entire length of each bar. Tabs 12 b act as a stop for the upper end and lower end of each picket 18 . The width “w” of each picket 18 is such that each picket fits snugly within passageway 12 a in the elongated channel along the length of the extruded, aluminum bar 12 . Note that because of the cross-sectional shape of the channel passageway and walls 12 a and tabs 12 b which project laterally and inwardly, the channel 12 a can receive snap-in spacer plugs 22 , (which are extruded aluminum bars of a predetermined length, which also snap snugly into the elongated channel 12 a ) that are used to separate and retain pickets 18 apart from each other. Bar 14 is used as the lower support bar in the railing 10 shown in FIG. 1 and also receives snap-in spacer plugs 22 . The vertical pickets 18 can be spaced and held physically apart by a snap-in spacer plug 22 the length of which determines the fixed distance between adjacent pickets which may be inches or feet as desired. During manufacture and assembly of the railing 10 , the snap-in spacer plugs 22 are manually snapped into the channel 12 a and channel 14 a and are positioned between each picket 18 . The snap-in spacer plugs 22 can be extruded and cut in desired lengths or can be cut on site when the railing 10 is assembled. Pickets 18 can also be cut in desired lengths. The snap-in spacer plugs 22 have a unique cross-sectional configuration. The walls 22 b form a u-shaped portion that snugly engages or fits within walls 12 a in the outer channel and a pair of flanges 22 a that fit in inner channel 12 d formed by tabs 12 b to interlock the snap-in spacer plug in the channel. The tabs 12 b are tapered on their ends to facilitate engagement with the flanges 22 a of the snap-in spacer plugs 22 . Spacer plug flanges 22 a are tapered and inclined from a center longitudinal axis off of the end portion of each spacer plug wall 22 b to touch tabs 12 b on the bottom for a snug fit while reducing the amount of aluminum material required by the tapered flange 22 a construction. The snap-in construction of the spacer plugs renders the railing easier to install so that less labor is required to complete the task.
As shown in FIG. 1 , it should be noted that once the railing 10 is assembled such that all the pickets 18 and snap-in spacer plugs 22 are in place, the end pickets 18 e are welded at 18 w , and the end bars 1120 are then welded at each end top and bottom to bars 12 and 14 forming an integral, rigid unit from which the spacer plugs 22 and pickets 18 can not be removed.
The anchoring posts 16 are welded to the top bar 12 as shown in FIGS. 5 a and 6 . FIG. 5 a also shows how picket 18 fits within the passage 12 a and the fact that post 16 is welded along 16 a to firmly attach the upper bar 12 to the post 16 . FIG. 6 shows the top portion of post 16 and the rectangularly shaped end face 16 a that are formed in the upper portion in FIG. 6 of post 16 that engages a flat segment on the support bars 12 suitable for welding for attaching the bar 12 to the top portion of post 16 at end face 16 a . FIG. 5 b shows how the bottom bar 14 is attached typically to vertical post 16 . The bottom bar 14 has a cut recessed portion 14 c , which is a rectangular cutout portion from the bar 14 to allow the bar 14 to be welded along points 14 w at the top and bottom of the bar to the post 16 exterior surface. This is different than the attachment to the top bar 12 to post 16 as shown in FIG. 5 a . The vertical picket 18 end would fit within channel 14 a along the bottom bar 14 . By cutting out a rectangular segment along the length of bar 14 that fits the width of post 16 , there is a snug fit in conjunction with the weld points 14 w to rigidly hold the bar 14 and support the entire unit to post 16 .
Referring now to FIG. 7 , the snap-in spacer plug 22 is shown mounted between pickets 18 with respect to the upper bar 12 in a typical arrangement. The top and bottom ends of each of the pickets 18 fits in the lower portion of the passage 12 a against the tabs 12 b . The spacer plugs 22 fit snugly against each of the pickets 18 holding each picket firmly in place on each side. In this way, the pickets 18 cannot be removed from the railing. The snap-in spacer plugs 22 hold each picket 18 vertically and firmly in place at top and bottom. Note that there is no welding between the pickets 18 and the top bar 12 and the bottom bar 14 (except the outermost end pickets) and the spacer plugs 22 . Spacer bar flange 22 a engages tabs 12 b and wall segment 12 cc that retains and interlocks snap-in spacer bar 22 in place in inner channel 12 d.
The method of assembling the railing 10 without having to weld the pickets 18 to the top and bottom bars 12 and 14 while still maintaining the pickets 18 spaced apart rigidly in an integral unit greatly increases strength and reduces the cost of the manufacture of the railing while maintaining a rigid structure. The structural integrity of the railing and safety as a guard and barrier is not sacrificed in its construction. The perpendicular end faces of the pickets engage the top and bottom bar channel walls 12 cc while the perpendicular end faces 22 a of spacer plugs 22 engage the sides of pickets 18 , firmly holding all of the pieces in place.
FIGS. 8 a and 8 b show an alternate embodiment of the invention. The railing 100 as shown in FIG. 8 a is mounted on an earth incline relative to gravity and a plumb line (such as a hill) that may have an angle alpha relative to a flat (perpendicular to a plumb line) area. In this case the pickets 180 are mounted plumb vertically and parallel to the plumb vertical support posts 160 which would represent a plumb line relative to the ground. The configuration top support bar 120 and the bottom support bar 140 remain the same as shown in the preferred embodiment in FIGS. 1 through 7 in terms of their cross-sectional shape and the relationship between the spacer bars and the pickets. However, to ensure a snug fit on an incline, the ends of the pickets 180 , the end face 180 a and the bottom end face of the picket 180 a must be angled to accommodate fitting snugly in the bar channel 120 for receiving the pickets. Also, spacer bars 220 have their end faces 220 a cut at an angle alpha to properly engage the sides of each picket 180 for a flush engagement as shown in FIG. 8 a . Thus in the method employed as shown in FIGS. 8 a and 8 b , once the angle of incline is determined, then the end faces 180 a of the pickets 180 are cut at a similar angle so that the pickets fit in the top and bottom support bar 120 and 140 channels. Also the spacer plug end faces 220 a are cut at the same angle that is necessary to ensure snug engagement against adjacent pickets 180 to keep them firmly in place. The spacer bar lengths can be individually cut in length of different lengths for a “custom fit” to space the pickets at different distances apart in the same railing.
The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art. | A sturdy aluminum pedestrian and bicyclist safety railing that reduces the amount of welding required during construction, comprising top and bottom rigid bars, each having a longitudinal, radially extending exterior passage and a plurality of aluminum pickets mounted within said bar top and bottom channels and held apart by a plurality of spacer plugs that interlock and snap snugly into each top and bottom bar channel and act as spacers to separate the pickets. The top and bottom bars may be welded together at each end of the railing to hold the entire unit together, retaining the plurality of rigid pickets that are substantially perpendicular (or inclined) to the top and bottom bars. The pickets are supported in the top and bottom bar channels without welding for increased strength and reduced cost of construction. | 4 |
LATIN NAME
[0001]
Prunus persica
VARIETAL DENOMINATION
[0002] Alpine Delight
BACKGROUND OF THE NEW VARIETY
[0003] The present invention relates to a new, novel, and distinct variety of peach tree, Prunus persica , and which has been denominated varietally as ‘Alpine Delight.’ The present variety of peach tree resulted from an on-going program of fruit breeding. The purpose of this program is to improve the commercial quality of low chill peach and nectarine varieties, by creating and releasing promising selections of Prunus species. To this end, I make both controlled and hybrid cross pollinations each year in order to produce seedling populations from which improved progenies are evaluated and selected.
[0004] The seedling, ‘Alpine Delight’ was originated by me, and selected from a population of seedlings growing in my experimental orchard, and which is located near Perth, Western Australia. The seedlings, grown on their own roots, were derived from a cross that I made in 2008 of the white-fleshed, nectarine 4-1WN (unpatented), and the white fleshed peach 3-3WP (unpatented), and which is an early season, white fleshed, non-melting, clingstone peach, and which was the seed parent. As the fruit ripened the resulting seed from, this cross was stratified, germinated, and then was subsequently grown in a greenhouse to an appropriate development stage. Subsequently, the new plants were field planted and then grown for further evaluation. One seedling, which is the present variety, exhibited especially desirable characteristics, and was then designated as ‘YT-5.’ This seedling was marked for subsequent observation. After the 2011 fruiting season, the newly identified variety of peach tree designated as ‘YT-5,’ was formally named ‘Alpine Delight.’ The new variety was then selected for advanced evaluation and re-propagation.
ASEXUAL REPRODUCTION
[0005] Asexual reproduction of this new and distinct variety of peach tree was accomplished by budding the new peach tree onto ‘Coastguard’ rootstock (un-patented). This was performed by me in my experimental orchard which is located near Perth, Western Australia. Subsequent evaluations of these asexually reproduced plants have shown those asexual reproductions run true to the original tree. All characteristics of the original tree, and its fruit, were established, and appear to be transmitted through these succeeding asexual propagations.
SUMMARY OF THE VARIETY
[0006] ‘Alpine Delight’ is a new and distinct variety of peach tree, which is considered of large size, and which has a vigorous growth characteristic. This new peach tree is also a regular and productive bearer of relatively large, firm, white fleshed, clingstone fruit which has a good flavor and eating qualities. This new peach tree has a very low chilling requirement of approximately 100 hours, and further produces relatively uniformly sized fruit throughout the canopy of the tree. In addition to the foregoing, the fruit of the new peach tree also appears to have good handling and shipping qualities.
[0007] The ‘Alpine Delight’ peach tree bears fruit which are ripe for commercial harvesting on approximately October 1 to October 15 under the ecological conditions prevailing near Perth, Western Australia. The fruit of the subject variety exhibits a larger fruit size than the pollen parent 4-1WN (unpatented); and further has a slightly smaller but more highly colored fruit than the seed parent 3-3 WP (unpatented). The new variety ripens approximately 15 days earlier than the seed parent at the same geographical location.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings, which are provided, are color photographs of the new peach variety.
[0009] FIG. 1 depicts a whole mature fruit, which is sufficiently mature for harvesting and shipment; a twig bearing typical leaves, and a mature stone derived from a mature fruit.
[0010] FIG. 2 depicts the flowering characteristics of the new, and novel variety of peach tree.
[0011] FIG. 3 depicts several mature fruit of the present variety, and which are positioned in various orientations so as to show the shape, and size of the mature fruit; and one mature fruit has been dissected longitudinally so as to display the flesh coloration and stone characteristics thereof.
[0012] The colors in theses photographs are as nearly true as is reasonably possible in a color representation of this type. Due to chemical development, processing and printing, the leaves and fruit depicted in these photographs may, or may not be accurate when compared to the actual specimen. For this reason, future color references should be made be made to the color plates (Royal Horticultural Society) and descriptions which are provided, hereinafter.
NOT A COMMERCIAL WARRANTY:
[0013] The following detailed description has been prepared to solely comply with the provisions of 35 U.S.C. § 112, and does not constitute a commercial warranty, (either expressed or implied), that the present variety will, in the future, display all the botanical, pomological or other characteristics as set forth, hereinafter. Therefore, this disclosure may not be relied upon to support any future legal claims including, but not limited to, breach of warranty of merchantability, or fitness for any particular purpose, or non-infringement which is directed, in whole, or in part, to the present variety.
DETAILED DESCRIPTION
[0014] Referring more specifically to the pomological details of this new and distinct variety of peach tree, the following has been observed during the third fruiting season under the ecological conditions prevailing at the orchard of the inventor, and which is located near the city of Perth, Western Australia. All major color code designations are by reference to the R.H.S. Colour Chart (Fifth Edition), and which is provided by The Royal Horticultural Society of Great Britain. Common color names are also occasionally used.
Tree:
Size .—Generally — Considered large as compared to other commercial peach cultivars ripening in the early season of maturity. The tree of the present variety was pruned to a height of approximately 270 cm to about 310 cm at commercial maturity. Vigor .—Considered vigorous. The present peach tree variety grew to about 300 cm in height during the first growing season. The new variety was pruned to a height of approximately 200 cm during the first dormant season. Productivity .—Very productive. Fruit set varies from more than the desired crop load to levels much higher than the desired levels when grown in a suitable horticultural zone, and under appropriate commercial conditions. The fruit set is spaced by thinning to develop the remaining fruit into the desired market-sized fruit. The number of the fruit set varies with the prevailing climatic conditions, and the cultural practices employed. Therefore, productivity is not a distinctive characteristic of the new variety. Fruit bearing .—Regular. Fruit set has been more than adequate during the previous years of observation, and thinning was necessary during the past 3 years on both the original seedling and on subsequent asexually reproduced trees. Form .—Upright, and pruned into a central leader shape. Density .—Considered moderately dense. The resulting fruit will color to a commercially acceptable degree with minimal pruning.
Trunk:
Diameter .—Approximately 12 cm in diameter when measured at a distance of approximately 15 cm above the soil level. This measurement was taken at the end of the third growing season. Bark texture .—Considered moderately rough, and having numerous folds of papery scarfskin. Since the bark development and coloration change with advancing tree age, this characteristic varies with the tree vigor, age and regional conditions. Therefore, this is not a dependable descriptor of the new variety. Lenticels .—Abundant on new bark. The lenticels are oval in shape, and are approximately 3.0 to 5.5 millimeters in width, and 2.0 millimeters in height. Bark coloration .—Variable, but it is generally considered to be a medium brown, RHS Greyed-Orange Group 165B. This bark coloration was taken from trees in their third leaf. It should be noted that the coloration of the bark is influenced, and varies, as the smoother, darker background color approaches other bark features, and the initial fissures which form a feature of the scarfskin development.
Branches:
Size .—Considered medium for the variety. Diameter .—Average as compared to other peach varieties. The branches have a diameter of about 4 centimeters when measured during the third year after grafting. Surface texture .—Average. Crotch angle .—Primary branches are considered variable, and are usually growing at an angle of about 50 to about 60 degrees when measured from a horizontal plane. This characteristic can be influenced, to some degree, by tree vigor, rootstock and other cultural conditions. Current season shoots .—Surface texture — Substantially glabrous. Internode length .—Approximately 3.5 cm. Color of mature branches .—Grey brown, RHS Grey-brown Group 199B. Current seasons shoots .—Color — Medium light green, RHS Green Group 144B. The color of new shoot tips is considered a bright and shiny yellowy-green, RHS Yellow- Green Group N144D. The vegetative shoot color can be significantly influenced by plant nutrition, irrigation practices, and exposure to sunlight, and therefore should not be considered a consistent botanical characteristic of this variety.
Leaves:
Size .—Considered medium to large for the species. Leaf measurements have been taken from vigorous, upright current season growth, taken at approximately mid-shoot. It should be understood that the leaf size is often influenced by prevailing growing conditions, quality of sunlight, and the location of the leaf within the tree canopy. For this reason, leaf sizes can vary significantly based upon the ambient and cultural factors listed above, and are not typically considered a dependable botanical descriptor. Leaf bud burst occurs approximately with the first bloom. Leaf length .—Approximately 200-230 millimeters. Leaf width .—Approximately 40-50 millimeters. Leaf base - shape .—The leaves generally exhibit equal marginal symmetry relative to the leaf longitudinal axis. Leaf form .—Lanceolate. Leaf tip form .—Acuminate. Leaf color .—Upper leaf surface, RHS Green Group, 136A. Leaf texture .—Glabrous. Leaf color .—Lower surface, RHS Green Group, 137B. Leaf venation .—Broadly pinnately veined. Mid-vein .—Color — Considered a light yellow-green, RHS Yellow-Green Group, 150A. Leaf margins .—Gently undulating. Form .—Considered bluntly serrate. Uniformity .—Considered generally uniform. Leaf petioles .—Considered canaliculated, that is, having a shallow channel, and more pronounced trough as seen from the dorsal aspect. The petiole margin is considered rounded when viewed from the ventral aspect. Size .—Considered large. Length .—About 15 to 20 mm. Diameter .—About 2.0 to 2.5 mm. Color .—RHS Yellow Green Group, 146B. Leaf glands size .—Considered average for the species, approximately 1 mm in length, and about 1 mm in height. Number .—Generally one to two glands per marginal side are found. Type .—globose. Color .—RHS Yellow -Green Group 153A. Leaf stipules size .—Medium-large for this variety. Number .—Typically 2 per leaf bud, and up to 6 per shoot tip. Form .—Lanceolate in form, and having a serrated marginal edge. Color .—Green, RHS Green Group, 138A when young, but graduating to a brown color, RHS Greyed-Red Group 182A with advancing senescence. The leaf stipules are generally considered to be early deciduous.
Flower buds:
Date of first bloom .—Observed on 30 Jun. 2013. Blooming time .—Considered early in relative comparison to other commercial peach cultivars grown in the same region. The date of full bloom was observed on Jul. 7, 2013. The date of full bloom varies slightly with climatic conditions, and prevailing cultural practices. Flower bud color at pre-bloom and prior to scale separation is green-purple, RHS Greyed-Purple 187C. Duration of bloom .—Approximately 14 days. This characteristic varies slight with the prevailing climatic conditions. Flower type .—The variety is considered to have a showy type flower. Flower size .—Considered medium to large. The flower diameter at full bloom is approximately 40 mm. Bloom quantity .—Considered abundant. Flower bud frequency .—Normally one to two flower buds appear per node. Petal size .—Generally considered medium for the species. Length .—Approximately 15 to 18 mm. Width .—Approximately 12 to 15 mm. Petal form .—Considered an apically rounded ovate. Petal count .—Nearly always 5. Petal texture .—Glabrous. Petal color .—Considered a light pink at the popcorn stage, RHS Red-Purple Group 68A, and darkening with advancing senescence, and the exposure of the petals to sunlight to a medium dark pink, RHS Red-Purple 64C. Fragrance .—Slight. Petal claw form .—The claw is considered ovate, and is generally medium large when compared to other varieties. Length .—Approximately 10 to 13 mm. Width .—Approximately 9 to 11 mm. Petal margins .—Generally considered variable, from nearly smooth to moderately undulate. Petal apex .—Occasionally a small, axially centered groove is noted. Flower pedicel length .—Considered medium long with an approximate length of about 3.5 to 4 mm. Diameter .—Approximately 2 mm. Color .—RHS Grey-Brown 199B. Floral nectaries .—Color: RHS Orange-Red Group 33A. Upper portion of the calyx .—Surface texture — Generally glabrous; Color- RHS Greyed-Purple Group 183C. Lower portion of the calyx .—Surface texture — The surface has a short, fine pubescent texture; Size — Average; Color — RHS Greyed-Red Group 1758. Anthers .—Generally — Average in length. Color .—RHS Greyed-Red Group 181B. Pollen production .—Abundant. Color .—RHS Yellow-Orange Group 21 B. Fertility .—Self fertile. Filaments .—Size — Approximately 12 to 15 mm in length. Color .—RHS Red-Purple Group 65A. Pistil .—Number — usually one, and occasionally more than one. Size .—Average. Length .—Approximately 17 to 19 mm in length including the ovary. Color .—RHS Yellow-Green Group 150C.
Fruit:
Maturity when described .—Firm ripe condition (shipping ripe). Date of first picking: Oct. 2, 2013. Date of last picking: Oct. 18, 2013. The date of harvest varies slightly with the prevailing climatic conditions and the current cultural practices. Size .—Generally — Considered medium to large. Average cheek diameter .—Approximately 60 to 68 mm. Average axial diameter .—Approximately 58 to 63 mm. Typical weight .—Approximately 150 grams. This characteristic is quite dependent upon the prevailing Cultural practices, and therefore is not particularly distinctive of the new variety. Fruit form .—Generally — Considered slightly oblate. The fruit is generally uniform in symmetry. Suture .—Color — Generally blushed to the same degree as the skin, RHS Red-Purple Group 61B. Apex .—Shape — Rounded. Base .—Generally rounded, and smooth. Stem cavity .—The stem cavity is rounded and uniform in shape. The average depth of the stem cavity is about 10 mm. The average width of the stem cavity is about 15 mm. The average length of the stem cavity when measured in the sutorial plane is about 15 rm. Fruit skin .—Thickness: Considered medium, and tenacious to the flesh. Surface texture .—Short, fine and pubescent. The pubescence is lightly abundant. Taste .—Non-astringent. Tendency to crack .—Not observed in the previous years of observation and evaluation. Fruit skin color .—Blush Color — Generally a Red-Purple blush exists on a preponderance of the skin of the fruit RHS Red-Purple Group 61A. The blush color covers approximately 95% of the fruit skin surface. The percentage of the blush color of the fruit skin can vary, and is generally dependent on the fruit's position in the tree; specific fruit maturity; and also the prevailing ecological, and cultural conditions under which the fruit is grown. Ground Color .—Cream, RHS Yellow-White Group 158C. The ground color of the fruit can vary significantly based upon the maturity of the fruit when this measurement is taken. Fruit stem .—Size — Medium in length, approximately 8 to 10 mm. Diameter .—Approximately 2-3 mm. Color .—Pale Yellow-Green RHS Yellow-Green Group 152D. Fruit flesh .—Ripening — Considered even. Flesh Texture .—Firm, juicy and dense. Considered non-melting. Fibers .—Numbers — Few. Flesh aroma .—Strong. Eating quality .—Considered very good. Flavor .—Considered well balanced, and having a low acidity. Juice production .—Moderate to high. Brix .—About 10 to 15 degrees. This characteristic varies slightly with the number of fruit per tree; the maturity of fruit when harvested; the prevailing cultural practices; and the ambient climatic conditions. Flesh color .—It is considered a Cream White, RHS White Group 155D.
Stone:
Type .—Considered clingstone. Size .—Considered small to medium for the variety. The stone varies significantly depending upon tree vigor, the crop load, and the prevailing growing and cultural conditions. Length .—Averaging 25 to 30 millimeters. Width .—Averaging 21 to 25 millimeters. Diameter .—Averaging 18 to 20 millimeters. Form .—Roughly ovoid. Stone surface .—Surface texture: Considered smooth towards the apex, with pitting in the mid section of the stone, and to a lesser extent towards the base. Ridges .—Not overly apparent. Ventral edge .—The ventral edge is considered troughed with two reasonably distinguished edges running parallel to, and on both sides of the stone's suture. These distinct edges continue from the hilum to the apex. Dorsal edge .—Shape — Generally considered smooth. Stone color .—The color of a mature, dry stone is generally considered an orange brown, RHS greyed-orange group 165C. This coloration depends, to some degree, on the moisture content of the stone. This color is variable, however, and may also be affected by oxidation and sun bleaching. This variability in the color which is caused by sun exposure, and the stone's maturity would be considered an inconsistent descriptor of the new variety. Tendency to split .—Splitting has only been rarely noted. Kernel .—Size — Very small. Kernel form .—Uneven. Pellicle .—Slightly pubescent. Color RHS Greyed-Orange Group 164B. Use .—The present variety ‘Alpine Delight’ is considered to be a peach tree of the very early season of maturity, and which further produces fruit which are considered to be very firm, attractively colored, and which are suitable for both local and long distance shipping. Keeping quality .—Excellent. The fruit of this variety have been stored well for periods of up to 30 days after harvest, and at temperatures at or below 1.0 degrees Celsius. Shipping quality .—Good. The fruit of the new variety shows minimal bruising of the flesh or skin after being subjected to normal harvesting and packing procedures. The fruit of the new variety has a non-browning flesh. Resistance to insects and disease .—No particular susceptibilities have been noted. The present variety has not been tested to expose or detect any susceptibilities or resistances to any known plant and/or fruit diseases.
[0151] Although the new variety of peach tree possesses the described characteristics when grown under the ecological conditions prevailing near Perth, Australia, it should be understood that variations of the usual magnitude and characteristics incident to changes in growing conditions, fertilization, nutrition, pruning, pest control, frost, climatic variables and changes in horticultural management are to be expected. | A new peach tree variety is described and which is denominated varietally as ‘Alpine Delight’, and wherein the new peach tree variety produces fruit which are ripe for harvesting and shipment about October 2-15 under the ecological conditions prevailing near Perth, Australia. | 0 |
BACKGROUND OF INVENTION
[0001] This invention relates to an improved gear pump and method of making such a pump.
[0002] As is well known, gear pumps are widely used for a great variety of purposes. This is due to their ability to generate high pressures. Also these pumps generally have a compact size and shape.
[0003] In one commonly utilized type of gear pump there are a pair of intermeshing gears that are supported for rotation about parallel axes. These gears are positioned within a pumping cavity formed by a pump housing. The pump housing cavity has a generally figure 8 shape and is closed by end walls that are in confronting relationship to the flat end faces of the gears. Passages permit the flow of the pumped fluid to and from the space between the gears. Because of machining problems with the prior art type of pumps and their manufacturing methods it has been the practice to interpose bearing end plates between the gear end faces and the pump housing.
[0004] For example, published Japanese Patent Application Hei 08-93653 shows a typical prior art pump of this type. The pump main housing member is formed with the pumping chamber by a machining operation through one end face thereof. At the bottom of this cavity, a fillet will be formed of machining necessity. Thus the peripheral edge of the gears must be spaced from this projecting area of the pump housing to avoid interference. This spacing can and is accomplished in part by chamfering the edges of the gear teeth. This however leaves a void area where leakage of the pumped fluid will occur and thus the efficiency of the pump is decreased.
[0005] The amount of chamfering required can be reduced by utilizing bearing end plates that engage the flat ends of the gears as shown in FIG. 3 of the noted published Japanese Patent Application. However that adds to the size and cost of the pump. In addition the end plates themselves introduce clearances and areas where leakage can and does occur.
[0006] It is, therefore, a principle object of this invention to provide an improved, simplified pump construction and pump manufacturing methodology.
[0007] It is a further object of this invention to provide an improved, pump construction and pump manufacturing methodology that offers higher efficiencies and more compact construction than heretofore possible.
[0008] In the pumps of this type the gears are supported by gear shafts and at least one of these shafts is driven by some form of prime mover. The gears are expensive to manufacture and are formed from special materials. If they are made integrally with their shafts, as is common practice, the cost increases and the manufacturing can become more difficult. However if the shafts are made separate from the gears, a driving connection must be made to at least the driven gear. This normally is done by a key or pin connection. Those commonly used are costly and troublesome.
[0009] It is therefore a further object of this invention to provide a simplified and low cost way of coupling a pump gear and its shaft.
SUMMARY OF INVENTION
[0010] A first feature of the invention is adapted to be embodied in an intermeshing gear pump. The pump is comprised of an outer housing defining a pumping cavity in which a pair of intermeshing gears are journalled for pumping a fluid from a fluid inlet to the pumping cavity to a pumping outlet from the pumping cavity. The intermeshing gears have end faces at opposite sides of the gears extending perpendicularly to the rotational axes of the gears. The outer housing is comprised of a main body part and a pair of separate end plates affixed thereto. The main body part has an opening extending axially therethrough that defines a portion of the pumping cavity that faces the circumferential peripheral surfaces of the gears. The end plates each closing a respective side of the main body part opening and are in confronting relation to respective of the gear end faces for closing the pumping chamber. A fastener arrangement affixes the end plates and the main body part together.
[0011] A further feature of the invention is also adapted to be embodied in an intermeshing gear pump. In accordance with this feature, the pump is comprised of an outer housing defining a pumping cavity in which a pair of intermeshing gears are journalled for pumping a fluid from a fluid inlet to the pumping cavity to a pumping outlet from the pumping cavity. The intermeshing gears have end faces extending perpendicularly to the rotational axes of the gears at at least one side of the gears. The outer housing is comprised of a main body part defining at least in part the pumping cavity and an end plate affixed thereto and closing the pumping cavity. At least one of the gears forms a bore extending therethrough to receive a shaft. The end face of this one gear forms a slot extending perpendicularly to the bore of the gear. A coupling pin extends through the shaft and has at least one end portion received in the slot for non-rotatably coupling the shaft and the one gear.
[0012] Yet another feature of the invention is adapted to be embodied in a method of forming an intermeshing gear pump. The pump is comprised of an outer housing defining a pumping cavity in which a pair of intermeshing gears are journalled on respective shafts for pumping a fluid from a fluid inlet to the pumping cavity to a pumping outlet from the pumping cavity. The intermeshing gears having end faces extending perpendicularly to the rotational axes of the gears at opposite sides of the gears. The outer housing comprises a main body part and at least one separate end plate affixed thereto. The main body part has an opening extending axially therein that defines a portion of the pumping cavity facing the circumferential peripheral surfaces of the gears. The end plate closes a respective side of the main body part opening. A fastener arrangement affixes the end plate and the main body part together. The method comprising the steps of placing a pair of plates in abutting relationship. The abutting plates are held against transverse movement relative to each other. A pair of holes are drilled through the plates from one side of one of the plates and ending through the oppositely facing side of the other of the plates so that any burrs formed by the drilling operation will be formed on the oppositely facing side of the other of the plates. Then a cavity is machined in at least the oppositely facing side of the other of the plates of sufficient size to form the pumping cavity and in an area encompassing that of the previously drilled holes to remove any burrs formed by the drilling operation and form the main body part. Then the one plate is placed and affixed against the main body part in closing relation to the pumping cavity formed therein to form the end plate therefor.
BRIEF DESCRIPTION OF DRAWINGS
[0013] [0013]FIG. 1 is a side elevational view of a marine propulsion unit having a tilt and trim unit powered by a fluid pump embodying the invention and manufactured in accordance with the invention which propulsion unit is shown attached to the transom of a watercraft hull, shown partially and in section.
[0014] [0014]FIG. 2 is an enlarged elevational view of the tilt and trim unit broken away to show the pump.
[0015] [0015]FIG. 3 is a cross sectional view of the pump taken through the gear axes.
[0016] [0016]FIG. 4 is a top plan view of the pump with a portion of the top cover broken away to more clearly show the construction.
[0017] [0017]FIG. 5 is an enlarged view looking in the same direction as FIG. 4 but showing only the connection between one of the pump gears and its shaft.
[0018] [0018]FIG. 6 is a cross sectional view taken along the same plane as FIG. 3, but showing a phase of the manufacturing process.
DETAILED DESCRIPTION
[0019] Referring now in detail to the drawings, FIGS. 1 and 2 show a marine propulsion system, indicated generally by the reference numeral 11 , as this is a typical, but not the only, use of the invention. In the illustrated embodiment, the propulsion system 11 is comprised of an outboard motor 12 and a hydraulically operated tilt and trim unit 13 , that is shown in most detail in FIG. 2.
[0020] Referring now to FIG. 1, the outboard motor 12 is comprised of a power head 14 that contains a powering internal combustion engine that is not shown because of its containment in a surrounding protective cowling. The engine drives a drive shaft (not shown) that is journalled in a drive shaft housing 15 and into a lower unit 16 where it drives a propulsion device such as a propeller 17 .
[0021] The drive shaft housing 15 is connected to a steering shaft (not shown) that is journalled for steering movement about a generally vertically extending axis in a swivel bracket 18 in a manner well known in the art. The swivel bracket 18 is pivotally connected to a clamping bracket 19 by a pivot pin 21 , in a manner that is also well known in the art. The clamping bracket 19 is suitably connected to the transom of a watercraft hull 22 , operating in a body of water 23 .
[0022] Except for its powering pump, to be described shortly, the function and operation of the tilt and trim unit 13 is as well known in the art to trim or tilt the outboard motor 12 up in the direction of the arrow U or down in the direction of the arrow D. In addition the tilt and trim unit 13 may function as a shock absorber to permit the outboard motor 12 to “pop up” when an underwater obstacle is met and to return to the trim adjusted position when it is cleared.
[0023] Referring now primarily to FIG. 2, the tilt and trim unit 13 is comprised of a hydraulic cylinder housing, indicated generally at 23 , having one end pivotally connected to the clamping bracket 19 on the hull 22 by a pivot shaft 24 . The cylinder housing 23 forms a cylinder bore 25 that is divided by a piston 26 into first and second pressure oil chambers 27 and 28 . A piston rod 29 is fixed to the piston 26 and extends through the chamber 28 and out of the cylinder housing 23 where it is connected by a pivot shaft 31 to the swivel bracket 18 . By pressurizing the chamber 27 and exhausting the chamber 28 the outboard motor 12 will move for upward tilting action U. Conversely pressurizing the second pressure oil chamber 28 and exhausting the chamber 27 will effect the outboard motor 12 to move downward for returning action D. The construction and operation of the unit 13 is well known in the art and thus further description except for its pump, next to be described, is not believed necessary. This is particularly true since the use of the pump is not so limited.
[0024] The pump, indicated generally by the reference numeral 32 , comprises an intermeshing gear pump supported by threaded fasteners 33 on the cylinder 23 , a reversible electric motor 34 for driving the gear pump 32 , and, indicated generally at 35 for introducing oil which is a pressurized fluid delivered from the gear pump 32 driven by the electric motor 34 into the cylinder 23 .
[0025] The gear pump 32 is supported by the threaded fasteners 33 on the cylinder 23 and comprises a housing assembly 30 , made of an iron-based sintered metal, constituting the outer shell of the gear pump and defining a pumping cavity, indicated generally by the reference numeral 36 , see now additionally FIGS. 3 - 5 . A pair of spur gears 37 , 38 are contained in the pumping cavity 36 with their axial centers 39 , 41 disposed parallel, and meshing with each other. Shaft receiving holes 42 , 43 are formed in the housing assembly 30 and the gears 37 , 38 on the axial centers 39 , 41 . Supporting shafts 44 , 45 are inserted in these shaft holes 42 , 43 and journalled at both ends on the housing assembly 30 for supporting these gears 37 , 38 for rotation about the axial centers 39 , 41 . At least either one of these supporting shafts 44 , 45 is driveably connected to the reversible electric motor 34 . The gears 37 , 38 are of the same shape and the same size and their flat end faces are flush with each other.
[0026] The internal surface of the pumping cavity 36 is formed by a pair of inside cylindrical surfaces 46 , 47 that extend parallel to the axial centers 39 , 41 and directly face the two gears 37 , 38 in close proximity to the outside surfaces thereof. This forms a generally figure 8 shaped recess facing directly the outside circumferential surfaces of the two gears 37 , 38 in close proximity thereto.
[0027] The housing assembly 30 is made up of first, second and third pieces 48 , 49 , 51 , each of a flat plate-like shape. These pieces 48 , 49 and 51 are stacked together in this order in direct contact with the piece 49 forming the main pump body and the pieces 48 and 49 forming upper and lower end closures therefore. Threaded fasteners 52 detachably fix these first, second and third pieces 48 , 49 , 51 together. However locating pins 53 position the first, second and third pieces 48 , 49 , 51 to each other prior to the fixing by the threaded fasteners 52 . In addition the threaded fasteners 33 fix the first, second and third pieces 48 , 49 , 51 together when the gear pump 32 is supported on the cylinder 23 , and thus have the same function as the threaded fasteners 52 .
[0028] The threaded fasteners 33 pass through holes 54 provided through the housing assembly 30 parallel to the axial centers 39 , 41 and are screwed into taped openings formed in the cylinder 23 . In a similar manner the threaded fasteners 52 pass through holes 55 provided through the first and second pieces 48 , 49 parallel to the axial centers 39 , 41 , and are received in tapped openings 56 formed in the third piece.
[0029] The locating pins 53 are positioned in aligning holes 57 provided in the first, second and third pieces 48 , 49 , 51 be parallel to the axial centers 39 , 41 . As already noted and insertion of the locating pins 53 into the aligning holes 57 allows the first, second and third pieces 48 , 49 , 51 to be positioned accurately to each other.
[0030] A coupling device, indicated generally at 58 , is provided for coupling the gears 37 , 38 and the respective support shafts 44 , 45 so that the gears 37 , 38 rotate with the support shafts 44 , 45 , respectively. The coupling means 58 is shown best in FIG. 5 and comprises coupling grooves 59 formed on one flat face of the gears 37 , 38 adjacent the housing piece 48 . Theses grooves 59 receive the ends of coupling pins 61 that penetrating radially through suitable openings formed in the support shafts 44 , 45 . The pins 61 are inserted in the coupling grooves 59 with a small play in a clearance-fit relation.
[0031] As shown in FIG. 3, the lower ends of the shafts 44 and 45 and the upper ends of the shaft holes 42 and 43 are chamfered significantly to facilitate assembly.
[0032] Referring now primarily to FIG. 3 and also FIG. 4, the oil introducing device and reservoir 35 comprises a pair of oil passages 62 and 63 are formed in lower end plate 51 of the housing assembly 30 . The oil passage 62 allows the area of one of two portions of the pumping cavity 36 formed on both sides of the mutual meshing portion of the gears 37 , 38 to communicate with the outside of the housing assembly 30 . The other oil passage 63 allows the other of two portions of the pumping cavity 36 to communicate with the outside of the housing assembly 30 . The passages 62 and 62 communicate with these portions of the pumping cavity 36 through recesses 64 and 65 , respectively, formed in the lower face of the main housing portion 49 .
[0033] In addition to the oil passages 62 and 63 , the oil introducing device 35 comprises still another two oil passages 66 and 67 for providing communication of the recesses 64 with a reservoir 68 of the device 35 . Ball type check valves 69 in enlargements of the lower end plate passages 66 and 67 permit the drawing of make up fluid from the reservoir 68 .
[0034] The passage 62 communicates with the chamber 27 of the cylinder 23 through a conduit 71 which is external of the pump housing 50 . In a like manner the passage 63 communicates externally with the cylinder chamber 28 through a conduit 72 . As is well known in the art, shuttle valves 73 are provided in the passages 71 and 72 to permit reverse flow. Pressure relief valves 74 and 75 are provided in the conduits 71 and 72 respectively for limiting the maximum pressure exerted in the cylinder chambers 27 and 28 , respectively. There are also provided a pair of pressure relief valves 76 between the shuttle valves 73 and the reservoir 68 for a similar purpose.
[0035] As seen in FIGS. 3 and 4, when the electric motor 34 is operated in the trim up direction to rotate the gears 37 , 38 in the trim up directions U, respectively, remembering that the gears 37 , 38 are rotated the opposite directions due to their intermeshing relationship, pressure oil is delivered from the gear pump 32 passages 64 and 62 . This pressurized oil is supplied to the first pressure oil chamber 27 of the cylinder 23 through the oil introducing device 35 , as shown in these figures by the solid lines, so that the cylinder 23 extends to move the outboard motor 12 for upward tilting action U. Since the external circuitry is well known in the art it is not believed necessary to describe its operation any further. It should also be remembered that this environment is only one of many possible uses for the pump 32 .
[0036] On the other hand, when the electric motor 34 is operated in the reverse direction to rotate the gears 37 , 38 in the reverse directions D, respectively (gears 37 , 38 are rotated reversely in the directions opposite to those of the previous case), pressure oil delivered from the gear pump 32 is supplied to the second pressure oil chamber 28 of the cylinder 23 through the oil introducing device 35 , as shown in FIGS. 1 and 4 by single dot and dash lines, so that the cylinder contracts to move the outboard motor 12 for downward returning action D. Again, since the external circuitry is well known in the art it is not believed necessary to describe its operation any further.
[0037] Next, by principal reference to FIG. 6, which should also be compared to FIG. 3, a method of forming the gear pump 32 will be described, as this constitutes an important feature of the invention. In FIG. 6, work pieces that will eventually become the main body housing 49 , and the upper and lower end closures 48 and 51 . These work pieces before machining are indicated in FIG. 6 by the reference numerals 81 , 82 and 83 , respectively. That is the work piece 81 will become after machining the main body housing 49 and the work pieces 82 and 83 will become the upper and lower end closures, respectively.
[0038] First, second and third work pieces 81 , 82 , 83 are formed each having the same thickness and size as the respective final housing pieces 48 , 49 , 51 . However, for reasons that will shortly become apparent, the work pieces are initially stacked and retained in an order different from their final assembled positions. They are stacked together in the order of the second, the first and the third work pieces 82 , 81 , 83 in direct contact and fixed together by a suitable mechanism.
[0039] Then, the shaft holes 42 , 43 are machined with a tool such as a pair of drills 84 from the lower side of the third work piece 83 through the first work piece 81 toward the upper side of the second work piece 82 . In this case, when the shaft holes 42 , 43 are drilled in the second work piece 82 , burrs indicated at 85 are normally produced at the edges of the holes on the ending side of the drilling operation. However, the shaft holes 42 , 43 are not necessarily machined through the upper side of the second work piece 82 to practice the invention.
[0040] Then, in the second work piece 82 is machined, with another cutting tool to form thepumping cavity 36 having a constant cross-sectional shape in the direction of depth, through the entire thickness of the second work piece 82 . This machining is preferably continued into the first work piece 81 on the side adjacent the second work piece 82 to form a recess 86 of the same cross-section in shape and size as the pumping cavity 36 but preferably of lesser axial length. In this case, the burrs 85 are automatically eliminated in association with the formation of the pumping cavity 36 .
[0041] The bolt through holes 54 andlocating pin holes 57 are formed in the first, second and third work pieces 81 , 82 , 83 to form the first, second and third pieces 48 , 49 , 51 . These pieces are then separated to perform the threading operation in the piece 83 and the oil passage drilling operation and such other machining in the main body work piece 82 and lower end closure work piece 83 as required.
[0042] Then the resulting pump pieces are rearranged in their final order. After that, the gears 37 , 38 , support shafts 44 , 45 , coupling means 58 and knock pins 56 are incorporated in these pieces and then the first, second and third pieces 48 , 49 , 51 are put together directly in this order and fixed with the threaded fasteners 52 . The formation of the gear pump 32 is thereby completed.
[0043] Because of this arrangement, the inside surfaces 46 , 47 of the pumping cavity 36 face directly the outside surfaces of the gears 37 , 38 . As previously noted, in the prior art, sliding plates are provided between the end faces of the gears 37 , 38 and the inside surfaces 46 , 47 of the pumping cavity 36 . That is not necessary here since no fillet results at the bottom of the pumping cavity 36 . Therefore in this invention, the size of the housing assembly 30 can be decreased, that is, the size of the gear pump 32 can be decreased.
[0044] Therefore, in forming the housing assembly 30 , a hole having the same cross-section in shape and size as the pumping cavity 36 when viewed in the direction of the axial centers 39 , 41 is first machined through a flat plate member of the same thickness as the second piece 49 to form the second piece 49 . Then the first, second and third pieces 48 , 49 , 51 are put together in this order, so that the inside surfaces 46 , 47 of the pumping cavity 36 are defined by the first and third pieces 48 , 51 , and the inside circumferential surface 38 of the pumping cavity 36 by the second piece 49 , that is, the piece 30 containing the pumping cavity 36 is formed.
[0045] In this case, it can be ensured more reliably in association with the formation of the pumping cavity 36 that corners of the opening ends of the pumping cavity 36 open to the outsides from the second piece 49 are shaped to be right angular. Therefore, the corners of the pumping cavity 36 defined by the inner surfaces 46 , 47 and the inside circumferential surface 38 can be each formed into a right angular shape more reliably. Thus, if the peripheral corners of the gears 37 , 38 are shaped to be right angular and the inside corners and the peripheral corners are fitted together, clearances between the peripheral corners and the inside corners can be significantly decreased compared with when they are shaped in arcs and fitted together.
[0046] Therefore, partial return of pressure oil from the delivery side to the suction side through the foregoing clearances in the prior art constructions is prevented. Thus during operation of the gear pump 32 the pressure of the pressure oil delivered from the gear pump 32 can be increased to a sufficiently high value. Also, because the mating surfaces of the first, second and third housing pieces 48 , 49 , 51 are flat these outside surfaces can be easily formed with high accuracy, which allows easy formation of the gear pump 32 .
[0047] Also as described above, the gears 37 , 38 are formed with shaft holes 42 , 51 on the axial centers 39 , 41 , and the support shafts 44 , 45 are inserted in the shaft holes 42 , 43 . Therefore, since it is ensured that corners defined by the outside surfaces of the gears 37 , 38 and the outside circumferential surfaces of the support shafts 44 , 45 can be shaped to be right angular. Thus the corners of the opening ends of openings of the shaft holes 42 , 43 into to the pumping cavity 36 are shaped to be right angular and the corners of the gears and those of the opening ends of openings of the shaft holes are fitted together, clearances between these corners can be significantly decreased compared with when they are formed into arcs and fitted together.
[0048] Therefore, partial return of pressure oil from the delivery side to the suction side through the foregoing clearances is prevented more reliably during operation of the gear pump 32 , so that the pressure of the pressure oil delivered from the gear pump 32 can be increased to a sufficiently high value.
[0049] Also as described above, gears 37 , 38 and support shafts 44 , 45 are rotatable relative to their axial centers 39 , 41 , and coupling means 58 is provided for coupling the gears 37 , 38 and the support shafts 44 , 45 without fixing to each other such that said gears 37 , 38 rotate with said support shafts 44 , 45 . Therefore little play is produced between the gears 37 , 38 and the support shafts 44 , 45 , even if a forming error is produced in the degree of right angularity between the inside surfaces 46 , 47 of the pumping cavity 36 and the axial centers 39 , 41 of the support shafts 44 , 45 , this error is absorbed by the foregoing play, and the inside surfaces 46 , 47 of the pumping cavity 36 can be brought close to the gears 37 , 38 throughout their outside surfaces in close contact, so that clearances between the inside surfaces 46 , 47 of the pumping cavity 36 and the outside surfaces of the gears 37 , 38 can be significantly decreased.
[0050] Thus it should be readily apparent that a pump configured and manufactured as described provides a high output and compact configuration. Those skilled in the art will readily understand that the foregoing description is of preferred embodiments of the invention and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims. | An improved high pressure intermeshing gear pump that achieves high efficiency and a low cost by forming the pumping cavity such that no fillets exist at the corners permitting closed fits without utilizing bearing end plates. In addition an improved coupling between the gears and their supporting shafts is disclosed as is a simplified machining method that eliminates burrs that may be formed during the drilling operations. | 5 |
STATEMENT OF GOVERNMENT INTEREST
Research to develop a prototype of the invention was supported partially by a National Science Foundation grant NSF/ILI #DUE-9750725 and a Department of Energy Grant DE-FG07-98ER62706.
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to radiation detection techniques, and in particular to a new and useful non-destructive in-situ method and apparatus for determining the depth in a medium such as concrete, of radionuclides, between the radioactive source and a detector.
As a result of the Department of Energy's (DOE's) shift away from nuclear weapons production and the closing of nuclear power industry facilities, there has been a rapid increase in the number of sites and facilities which contain radioactive contaminants. A large part DOE and nuclear industry activity has been dedicated to the disposition of these facilities through various environmental restoration, and decontamination and decommissioning (D&D) projects. The resources spent on radiological characterization, monitoring and risk assessment contribute significantly to the anticipated total D&D budget of $265 billion dollars over the next 75 years.
Concrete is probably the most important medium or material for radiation shielding and operating structure in nuclear facilities. It has been estimated that there are approximately 73 km 3 of radioactively contaminated concrete material within 25 DOE facilities. Additionally the DOE estimates that over 550,000 metric tons of radiological contaminated metal will require characterization and disposition. In many cases, the contaminants are found not only on the surface, but also at depths below the surface of a medium.
Current practice in characterizing deeply contaminated concrete in DOE and nuclear industry facilities employ destructive approaches. In most cases, a surface survey is performed first, and then bore samples are taken manually. The samples are then sent to an off-site lab to analyze the depth profile. It usually takes days to weeks to obtain a result, whose accuracy is only as good as the bore sampling process. For a large contamination area, the task of making representative measurements can be too time-consuming to be practical. Further, because airborne radioactivity is generated when core bore samples are taken manually, occupational exposure is inevitable. The potential for internal exposure to radioactivity requires the use of protective equipment, which in turn slows down the worker's progress. The current practice in characterizing concrete contamination is inefficient and costly. The radiation protection philosophy of as-low-as-reasonably-achievable (ALARA) can be better accomplished through non-destructive means.
Gamma spectroscopy has been widely used for isotope identification and quantification by measuring the energies of the gamma rays, which can easily penetrate thick samples. When calibrated against a reference radioactive source, the radioactivity of the sample can be determined remotely. Despite these capabilities, gamma spectroscopy has not been demonstrated to be satisfactory for determining a contamination depth profile in-situ. The major difficulty is that while gamma spectroscopy utilizes the photopeaks from the uncollided gamma rays to identify radioisotopes, there has been no sufficient unfolding algorithm to determine the depth to which the gamma rays have penetrated. There is also a lack of tools that can quickly estimate the contamination activity levels and assess the doses or risk caused by the contamination. This information is crucial in deciding cleanup action and demonstrating compliance with regulations on releasing a facility.
Some of the more common contaminants have been reported recently. Table 1 lists the radiological information for some of these contaminants that emit gamma rays. The gamma energy lines are said to be the “finger prints” of these radiological contaminants. For example, it is possible to measure uranium isotopes by detecting the gamma energies, such as the 143 keV (10% yield) and 185 keV (50% yield) for 235 U. Highly efficient detectors are often used for isotopes with lower gamma energies and emission yields. The advantage of gamma ray spectroscopy is that gamma rays are much more penetrating than beta and alpha radiation, thus making non-destructive in-situ measurements possible. Table 1 provides the more important gamma lines and gamma yields for common isotopes that may be found in the DOE and nuclear industry. Additionally, 38 Cl is listed in Table 1 because the chlorine in salt, NaCl, may be neutron activated and subsequently emit two prominent gamma rays at 1642 keV (32.8% yield) and 2167 keV (44.0% yield).
TABLE 1
Gamma Energy
Radionuclide b
(MeV)
% Yield
60 Co
1.17323
99.86
(NTH 59 Co)
1.33251
99.98
(NFA 60 Ni)
(NFA 63 Cu)
59 Fe
1.09922
56.50
(NTH 58 Fe)
1.29156
43.20
(NFA 52 Ni)
(NFA 59 Co)
38 Cl
1.6424
32.80
(NTH 37 Cl)
2.1675
44.00
(NFA 41 K)
(NFA 38 Ar)
137 Cs
0.66162
84.62
(NTH 136 Xe)
0.03219
3.70
(NFA 136 Ba)
(NFI 6.210)
234 U
0.01360
10.40
(NTH 233 U)
0.05310
0.12
(NFA 235 U)
0.12100
0.04
(NAT 238 U)
235 U
0.14376
10.50
(NAT 235 U)
0.16335
4.70
0.18572
54.00
0.20531
4.70
238 U
0.01300
8.70
(NAT 238 U)
0.04800
0.08
235 Pu
0.04910
2.34
(CHA 235 U)
0.09708
19.50
(CHA 233 U)
0.10107
34.80
0.11400
13.60
0.11750
4.50
239 Pu
0.01360
4.40
(NTH 238 U)
0.05162
0.04
240 Pu
0.01360
11.00
(NTH 239 Pu)
0.04524
0.05
241 Am
0.01390
28.00
(NTH 240 Pu)
0.02636
2.50
0.05954
36.30
231 Th
0.01330
92.00
(NAT 235 U)
0.02664
18.70
0.08421
8.00
0.08995
1.25
234 Th
0.01330
9.80
(NAT 238 U)
0.06329
3.90
0.09238
2.57
0.09289
3.00
239 Np
0.01430
56.00
(NTH 238 U)
0.09950
15.00
0.10370
24.00
0.10613
22.70
0.11770
8.40
0.12070
3.20
0.22819
10.70
0.27760
14.10
235 Np
0.09466
22.00
(CHA 235 U)
0.09844
38.00
(CHA 233 U)
0.11100
15.00
0.11450
5.30
237 Np
0.02938
9.80
(NFA 238 U)
0.08649
13.10
0.09229
1.82
0.09507
2.96
0.10800
1.02
Items in parenthesis indicate the nuclear reactions producing the radioisotopes based on the bombarding particle and the target nuclei as follows: NTH by thermal neutron isotopes; NFA by fast neutron; CHA by charged particles (alpha, proton, deuterons, etc.); NAT by natural occurring isotopes; NFI by fission with cumulative fission yield in percent for thermal neutron fission of 235 U.
The technique of the present invention, as will be explained later in this disclosure, can then be used to determine the depth of salt embedded in pavement or concrete shielding pads. Salt contamination of rebars leads to cracks, potholes, etc. in concrete and pavement.
Many researchers have developed models that use in-situ gamma spectroscopy to estimate the depth of contamination in media. Most of the research has been in the detection of 137 Cs contaminant distributions in soil as a result of post-Chernobyl environmental characterizations.
Russ et al. (1996) developed a method using in-situ gamma spectroscopy on transite panels at the DOE Fernald site that required measurements using an uncollimated high purity germanium (HPGe) detector on both sides of the medium. Although the method showed potential for predicting the contaminant depth distribution throughout the thin transite panel, the method requires access to both sides of a medium. Insufficient information was also provide to determine the technique used for any unfolding algorithm that was used. In conjunction with knowledge of the gamma-ray linear attenuation coefficient for the material, the method used the ratio of the photopeak areas at several energies to infer the “most-probable” contamination distribution. Because the method used uncollimated HPGe detectors the in-situ gamma spectroscopy results were of the entire transite panels and local depth profiles across the surface area could not be obtained.
Korun et al. (1991) developed a method to determine depth distribution of 137 Cs concentrations in soils based on the energy dependence of attenuation of gamma rays in soil. The method assumed a decreasing exponential distribution in the radionuclide concentration. The decreasing exponential contains a special parameter referred to as the relaxation length. Laboratory and experimental results must be conducted to determine the parameter value. A limitation of the method is that it cannot be applied independently for radionuclides that emit gamma rays at a single energy without prior knowledge about the relaxation length parameter. The method also requires specific knowledge of the linear attenuation coefficients of the materials and the detector's absolute efficiency. The knowledge of the absolute efficiency is complicated in that the angular dependence of the detector's efficiency as a function of energy must be known. Korun et al. (1991) recognized that for inhomogeneously distributed radionuclei, the relaxation lengths overestimate the actual depth distribution due to oversimplification in the model.
Fülöp and Ragan (1997) improved on Korun's method for predicting depth using in-situ gamma spectroscopy specifically for 137 Cs concentrations in soil. This method makes use of gamma spectroscopy information from the scattered and unscattered gamma rays between the energy range of 0.620 MeV to 0.655 MeV. A limitation of the method is that it requires multiple measurements with and without collimators and it is designed specifically for 137 Cs only.
Rybacek et al. (1992) developed a method for depth determination by in-situ gamma spectroscopy. The method used the ratio of fluence rates of unscattered gamma rays of 137 Cs whose decay product of 137m Ba emits gamma-rays with energies of 0.662 MeV and 0.032 MeV. A limitation of the method is that it requires multiple prominent gamma peaks with large energy differences and was developed primarily for 137 Cs.
The methods described above have demonstrated success for using in-situ gamma spectroscopy to determine depth distributions for the specific purposes as designed. Most of the methods have been restricted to the characterization of 137 Cs in soil and consequently have limited applicability to DOE and nuclear industry facilities. An appropriate method for DOE and the nuclear industry using in-situ gamma spectroscopy would be one that improves on the limitations of all the methods described above and can be used for many radioactive isotopes such as those listed in Table 1.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and an apparatus for the non-destructive, in-situ determination of the depth of a radiological contamination in media using gamma spectroscopy and a gamma penetration depth unfolding algorithm (GPDUA) with point kernel techniques to predict the depth of contamination based on the results of uncollided peak information from the in-situ gamma spectroscopy. The invention provides a better, faster, safer and cheaper technique than the current practice for decontamination and decommissioning of facilities that pose a radiation danger. The invention uses a priori knowledge of the contaminant source distribution. The applicable radiological contaminants of interest are any isotopes that emit two or more gamma rays per disintegration or isotopes that emit a single gamma ray but have gamma-emitting progeny in secular equilibrium with its parent (e.g., 60 Co, 235 U, and 137 Cs to name a few)
The predicted depths from the GPDUA algorithm using Monte Carlo N-Particle Transport Code (MCNP) simulations and laboratory experiments using 60 Co have consistently produced predicted depths within 20% of the actual or known depth.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic view of an apparatus of the invention;
FIG. 2 is a schematic illustration of the radiation source-to-detector solid angle geometry of the invention;
FIG. 3 is a low chart of an analytic model derivation with verification and validation process of the invention;
FIG. 4 is a schematic view of an experimental setup to validate the utility of the invention;
FIG. 5 is a flowchart showing source type for a corresponding analytic algorithm to be solved by the GPDUA;
FIG. 6 is a schematic view of a point source-to-detector geometry;
FIG. 7 is a schematic view of a disk source-to-detector geometry;
FIG. 8 . is a flowchart for input requirements to the GPDUA;
FIG. 9 is a schematic illustration showing how gamma ray paths less then ten mean free paths through the lead collimator will generally reach the detector as shown with gamma ray paths B and C;
FIG. 10 . illustrates how a cone A has a smaller solid angle through the lead collimator than cone B, cone limits being ten mean free paths (10λ) as will be explained; and
FIG. 11 is a cutaway illustration of the geometry for the point kernel method used in the present invention, the differential cone being integrated over the surface of a detector.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An in-situ, gamma spectroscopy apparatus of the present invention is schematically illustrated in FIG. 1 . The apparatus comprises a portable HPGe detector 10 which is connected to a unit 12 that includes a multi-channel analyzer (MCA), a high voltage source and an amplifier unit. Such a unit is available commercially. An example is the InSpector product from Canberra Industries of Meriden Connecticut.
The apparatus includes a laptop computer 14 with counting and other software needed to practice the invention, and a single lead collimator 16 with a collimating aperture 18 for receiving gamma radiation from a radiological contamination or radionuclide 20 at an unknown depth D in a medium, such as a concrete wall 22 . The in-situ apparatus and method of the invention measures the surface activity from only one side of the medium or wall 22 as shown in FIG. 1 and can be run on rechargeable batteries for six hours, making it extremely useful for field work.
The method of the invention places no restrictions on the gamma spectrometry peak separation or relative peak height. The only requirement is that the peaks must be resolvable with a gamma spectrometer such as an HPGe or NaI detector. The resolution of the detector 10 used in research that confirmed the utility of the present invention had a Full Width at Half Maximum (FWHM) value of 2.0±0.03 keV at 1333 keV.
The lead collimator 16 serves two primary purposes. First, the lead collimator ensures that any assay of the radiologically contaminated medium is focused on a small area so that the entire surface of the medium can be mapped out with a depth profile.
Depth of radiological contaminants may vary in the medium and consequently this can only be discovered if the in-situ gamma spectroscopy is focused by the collimators. The ultimate goal of the invention is to provide a contour mapping of the depth distribution along the entire surface 24 of the medium. Second, the lead collimator simplifies efficiency calculations of the detector since it is necessary to use only a point particle contaminant source in order to determine the efficiency of the system.
The efficiency determination in essence becomes geometrically independent. To ensure that the response time for collecting gamma rays is as quick as possible, the solid angle created by the collimator opening 26 must be large enough while ensuring the first purpose of the collimator, as stated above, is not violated.
The method is applicable only to isotopes that emit two or more gamma rays 28 or if a single gamma-emitting isotope has gamma-emitting progeny in secular equilibrium. The uncollided peaks of the gamma spectroscopy contain the only information necessary for the Gamma Penetration Depth Unfolding Algorithm (GPDUA) of the invention. It is the ratio of the counts in the uncollided peaks that contains the necessary information to determine the depth D of the contamination 20 . This process will be discussed in the general theory using the narrow-beam approximation.
The General Theory Using the Narrow-Beam Approximation
Gamma ray transport under conditions of “good geometry” and a narrow-beam approximation will undergo attenuation based on the energy of the gamma rays and the material that the gamma rays transport through. The gamma ray attenuation relation for the “good geometry” narrow-beam approximation is
N=N 0 e −μx (1)
where N 0 and N are the number of gamma rays at the incident gamma ray energy in a narrow beam before and after the attenuation, respectively, and μ is the linear attenuation coefficient characteristic of the medium and energy of the gamma ray. The variable x, is the length of the medium that gamma rays propagate through without interaction. The gamma ray counts N 0 , refer to those gamma rays impacting on the detector surface. A fraction of these gamma rays will be recorded based on the counting efficiencies of the detector. Consequently, the uncollided peak counts from the collected spectrum must be corrected for the Compton continuum and for intrinsic efficiency of the detector in order to determine the counts impacting on the surface of the detector.
To ensure that narrow-beam approximations are valid for a system, not only is it necessary that the incident beam on the detector contains only uncollided gamma rays, but also gamma rays impacting the detector are normal to (or nearly normal to) the detector surface where the small angle approximation applies, tan θ≈θ, as shown in FIG. 2 .
When these conditions are met, the beam can be treated as a narrow-beam approximation. This becomes the basis for determining the collimator dimensions, detector locations, etc. in measuring gamma rays in-situ.
If the conditions of “good geometry” and narrow-beam are applicable then equation (1) is easily applied to produce an elegant and simple model to predict the depth of contamination for a point particle. From a source activity A 0 , the two gamma rays emitted will obey the narrow beam attenuation equations: N 1 ɛ 1 = A o Ω 4 π t 1 Y 1 - μ 1 x ( 2 ) N 2 ɛ 2 = A o Ω 4 π t 2 Y 2 - μ 2 x ( 3 )
where;
Y 1 , Y 2 =the gamma yields;
ε 1 , ε 2 =the intrinsic peak efficiencies of the detector for the respective gamma ray energies;
μ 1 , μ 2 =the attenuation coefficients of the gamma ray energies in the contaminated material;
N 1 , N 2 =are the uncollided peak counts from the gamma spectroscopy after the superimposed Compton scattering is subtracted;
A 0 =is the activity of the point source;
t 1 , t 2 =are the counting times which will typically be equal; and
Ω=the solid angle subtending from the point source across the detector surface.
Taking the ratio of equations (2) and (3), the narrow-beam approximation expression to determine the depth, x, of the contamination is, x = ln ( N 1 t 2 Y 2 ɛ 2 N 2 t 1 Y 1 ɛ 1 ) μ 2 - μ 1 . ( 4 )
The unknown contaminant activity A 0 , and the solid angle are canceled out in the ratio. Everything remaining in this expression is known data. The yield and linear attenuation coefficient for each gamma rays are published data. The intrinsic efficiencies can be predetermined for the detector. The ratio is the measured ratio of uncollided counts in the photopeaks from the gamma spectroscopy after the Compton continuum is subtracted.
This simple model is the basis of the theory of the invention. By taking the ratio of the uncollided peak counts in the gamma spectroscopy for both gamma rays emitted from the same source, any unknown information cancels in the ratio. This model is based on ideal and simple geometries.
Monte Carlo N-Particle Transport Code Version 4B (MCNP) (Breimeister 1997) simulations and laboratory experiments reveal that the narrow-beam approximation model defined in equation (4) produces discrepancies as high as 50% to 100% for the depth prediction. The primary reason for this high discrepancy is that the model is based on ideal and simple geometry which does not account for such effects as gamma ray transport through portions of the lead collimator. This realistic geometry effect will be referred to as the “lead effect.” The “lead effect” is described in more detail later in this disclosure.
Verification and Validation Process
The narrow-beam approximation model is the start point for a more rigorous treatment using point kernel techniques that account for the “lead effect” and can be applied to realistic and more complicated geometries.
The analytic model verification and validation process is as shown in the flow chart of FIG. 3 .
MCNP simulations were used to develop and verify the model. Validation of the model for point sources was also done through a laboratory experiment.
As shown later in this paper the uncollided peak counts contain the only information necessary for the depth prediction model. The uncollided peaks are those gamma rays that transport from the source to the detector without absorption or collisions. This allows source biasing in MCNP as the primary means for variance reduction. The direction of a gamma photon at birth is determined by the azimuthal angle (0 to 2 π) and a polar angle (0 to π). In reality, photons are emitted isotropically over a 4π solid angle. Directional biasing in MCNP permits focusing on a smaller range of azimuthal and polar angles. When using the biasing technique, particles are forced to be emitted from the source in a direction toward the detector, where all gammas are contained in a solid angle that encloses the entire detector volume. This method greatly improves the computational efficiency. The geometry for the MCNP simulations is similar to that for the laboratory experiment. The geometry is described in more detail in the following.
Depth Prediction Model Using Point Kernel Methods
The narrow-beam approximation model could be improved by including a correction factor(s) to account for the transport of gamma rays through portions of the lead collimator. The intent of the invention and this experiment to show the utility of the invention, was not to take the approach of determining correction factors(s), but to develop an analytic model that rigorously includes the transport of gamma rays through the lead collimator. This was accomplished using point kernel techniques combined with the fundamental approach described for the narrow-beam approximation model. Adapting the narrow-beam approximation model to rigorously include the effects of lead, leads to three additional analytic models as seen in FIG. 5 . Prior knowledge of the source distribution is required before the correct analytic model is used in the GPDUA according to the invention.
The underlying concept for the point kernel method is that gamma rays emitted from a point source 34 will undergo material and geometric attenuation as they are emitted in a solid angle e in FIG. 6 . If this solid angle is reduced to a small differential cone 40 , then the fluence of gamma rays emitted through the base of the differential cone approach that of a narrow-beam approximation. The gamma rays emitted from the base of this differential cone can be integrated over the surface 33 of the detector 31 in FIG. 4 . Detector 31 is surrounded by a lead collimator 30 with an aperture 38 opening through an end face 36 of the collimator. This will determine the total number of gamma rays impacting on the surface of the detector. Knowledge of the detector's intrinsic efficiency will allow comparison of the gamma spectroscopic results to the calculated surface counts by the point kernel method. Analogous to the discussion for the narrow-beam approximation model, the ratio of the surface counts at each gamma ray energy using the point kernel method will lead to the predicted depth of the contamination according to the method of the invention.
The material attenuation within the differential cone 40 approaches the conditions of ideal geometry and the narrow-beam approximation. As shown in FIG. 6, the point kernel method is applied within the differential cone 40 from the isotropic point source 34 to the detector differential surface area dA. The number of counts impacting on the surface 33 of the detector is determined by integrating the differential cone around the entire detector's surface. In general, the net counts on the surface of the detector can be expressed as N ( E ) = N ′ ( E ) ɛ ( E ) = ∫ Detector
Surface A o tY ( E ) G ( E , R ( x ) , θ ) A ( R ( x ) , θ , ω ) ( 5 )
where: N(E) is the net counts impacting the surface of the detector at gamma energy, E; N′ (E) is the net counts under the gamma spectroscopy peak at gamma energy, E, after the Compton continuum is subtracted; ε(E) is the intrinsic efficiency of the detector at gamma energy (E); A 0 is the activity of the source; t is the counting time; Y(E) is the gamma yield at gamma energy E; θ is the polar angle measured from the central axis to the differential cone; ω is the azimuthal angle from 0 to 2π; R(x) is the distance from the point source 34 to the detector surface 33 along the central axis; x is the depth of the contaminant point source along the central axis (that is the thickness of medium 32 in FIG. 4 ); dA[R(x),q, ω] is the differential area described by the differential cone along the detector surface; and G[E,R(x),θ] is the point kernel in the differential cone describing the detector response from the point source which is dependent on the gamma energy.
Within the differential cone, the gamma rays emitted from the point source undergo geometric and material attenuation before reaching the detector. The point kernel can be described in general as; G ( E , R ( x ) , θ ) = exp [ - μ ( E ) R ( x ) sec θ ] 4 π [ R ( x ) sec θ ] 2 ( 6 )
where the numerator represents the material attenuation and the denominator represents the geometric attenuation through the differential cone. The point kernel continuously changes as the differential cone is integrated across the detector surface.
A detailed development of the final form of the analytic model is disclosed later under a section entitled Derivation of the Point Kernel Model for Point Particle (PKMP). The GPDUA, written in FORTRAN code and stored as a computer program in the computer 14 of FIG. 1, iterates on the depth variable x, until the ratio of the integral on the right hand side of equation (5) for each gamma ray energy is within a specified tolerance of the ratio of the surface counts on the left hand side of equation (5). The ratio of surface counts is obtained from the simulation results of the MCNP uncollided peak counts or the gamma spectroscopy uncollided peaks after adjusting these counts for the Compton continuum and the intrinsic efficiency.
Depth Prediction Model/Disk and Linear Sources
The development of the point kernel model for a disk, planar, or line source (PKMD model) is very similar to that described for the point source in the PKMP model; however, there is one significant innovation that makes the method successful. In order to integrate the differential cone symmetrically around the detector surface, it is necessary to redefine the polar axis as the bisector of the angle from the point on the source disk also designated 34 , across the detector surface 33 . For every source point on the source disk, the polar axis is defined from that source point as indicated by T c in FIG. 7 . FIG. 7 demonstrates that the number of counts impacting on the surface of the detector is determined by integrating differential cones emanating from a differential source element (assumed to be an isotropic point source) to the differential area element along the detector surface. Integration in the model now occurs over the source as well as the detector surface. The general form of the PKMD model can be written N ( E ) = N ′ ( E ) ɛ ( E ) = A o Y ( E ) t ∫ Source ρ ρ ω ′ ∫ Detector G ( E , R ( x ) , θ ) A ( R ( x ) , θ , ω ) ( 7 )
In a process analogous to solving the PKMP, the GPDUA FORTRAN code performs double integration over the polar angle and the source disk radius. The code iterates on the depth of the contaminated disk until the ratio of the integrals on the right side of equation (7) for each gamma energy, converges to the ratio of the MCNP calculated (or MCA measured) uncollided surface counts on the detector.
The development of the model for a linear distributed source of activity (PKMLD) is analogous to that of the disk source. The distribution in depth is modeled as successive uniform disks in depth where each disk source activity decreases linearly with depth. The variation of activity in depth can be described in general as
S ( x ) dx=A ( x ) dx (8)
where A(x) is the uniform activity in the volume of the disk between depths x and x+dx. For a linear distribution of activity in depth, equation (8) is written, S ( x ) x = A 0 ( T - x T ) x ( 9 )
where A 0 is the surface activity if the depth was zero; T is the maximum depth of the contamination and x is the depth of the disk from the surface.
The general form of the PKMLD model can be written, N ( E ) = N ′ ( E ) ɛ ( E ) = A o Y ( E ) t ∫ Depth ( T - x T ) x ∫ Source ρ ρ ω ′ ∫ Detector G ( E , R ( x ) , θ ) A ( R ( x ) , θ , ω ) ( 10 )
The GPDUA FORTRAN code performs a triple integration over the polar angle, the disk radius, and the depth of the disks. The code iterates on the maximum depth, T, until the ratio of the integrals on the right hand side of equation (10) for each gamma energy converges to the ratio of the MCNP calculated (or MCA measured) uncollided surface counts on the detector.
MCNP and Experiment Results for Point Source Contaminant
All PKMP simulations and laboratory experiments were based on a 100 μCi 60 Co point contaminant. The counting time for laboratory experiment were anywhere from two to five minutes. Table 2 compares the depth prediction results based on MCNP simulations using the PKMP model. As evidenced in Table 2, the PKMP model provides a very good prediction of the point source contaminant depth to within 3% discrepancy of the actual depth. The depth predictions seem to improve with increasing depth primarily because the “lead effect” becomes more and more negligible. As the depth becomes greater, the solid angle between the point source and the detector surface becomes smaller to the point where the majority of gamma rays impacting on the lead collimator are 100% attenuated. This will be analyzed in more detail later when the “lead effect” is discussed.
Table 2 is shows the prediction results for a point contaminant in aluminum. The ratio of surface counts is determined from MCNP simulation. The value in the parenthesis is the percent discrepancy between the predicted and actual depths. Collimator radius is 1.27 cm, length is 20.32 cm, and distance from contaminated surface is 50.0 cm.
TABLE 2
Ratio of
Actual Depth
Surface Counts on
Predicted Depth PKMP Model
(cm)
Simulated MCNP Detector
(cm)
1.00
1.0157
0.97 ± 0.02 (2.95%
2.00
1.0255
1.97 ± 0.05 (1.50%)
5.00
1.0551
4.92 ± 0.11 (1.54%)
8.00
1.0862
7.95 ± 0.18 (0.62%)
10.00
1.1082
10.02 ± 0.23 (0.20%)
15.00
1.1610
14.86 ± 0.34 (0.93%)
Table 3 contains the results of changing the MCNP geometry to where the collimator radius is changed to 0.50 cm and the distance from the wall is changed to 10.0 cm. Again, the PKMP model provides outstanding predictions to within 2% discrepancy of the actual depth. The MCNP simulations verify that the PKMP prediction models provide very good predictions for the depth of point contaminants. The PKMP model is validated through laboratory experiments as previously described with the results as shown in Table 4. The PKMP model predicted depths are consistently within 5% discrepancy of the known depth.
Table 3 predicts results for a point contaminant in aluminum. The ratio of surface counts is determined from MCNP simulation. The value in the parenthesis is the percent discrepancy between the predicted and actual depths. Collimator radius is 0.50 cm, length is 20.32 cm, and distance from contaminated surface is 10.0 cm.
TABLE 3
Ratio of
Actual Depth
Surface Counts on
Predicted Depth PKMP Model
(cm)
Simulated MCNP Detector
(cm)
1.00
1.0230
0.99 ± 0.02 (1.05%)
2.00
1.0324
1.99 ± 0.04 (0.65%)
5.00
1.0615
4.97 ± 0.1 (0.50%)
8.00
1.0913
7.94 ± 0.18 (0.80%)
10.00
1.1119
9.92 ± 0.22 (0.80%)
15.00
1.1662
15.0 ± 0.34 (0.27%)
Table 4 shows experiment results for a point contaminant source. The value in parenthesis is the percent discrepancy between the predicted and actual depths.
TABLE 4
Predicted Depth
Actual
Ratio of
PKMP Model
Depth ± 0.07
Surface Counts
(cm)
(cm)
Material
from Experiment
(lead corrected)
1.18
Aluminum
1.0168
1.12 ± 0.08 (4.72%)
2.50
Aluminum
1.0308
2.54 ± 0.17 (1.41%)
3.80
Aluminum
1.0431
3.76 ± 0.26 (1.04%)
5.10
Aluminum
1.0568
5.12 ± 0.35 (0.33%)
6.40
Aluminum
1.0702
6.41 ± 0.44 (0.23%)
2.50
Polyethylene
1.1054
2.44 ± 0.18 (2.38%)
2.60
Polyethylene
1.1062
2.64 ± 0.20 (1.75%)
5.10
Polyethylene
1.0264
5.19 ± 0.38 (1.78%)
7.65
Polyethylene
1.0361
7.60 ± 0.57 (0.70%)
MCNP Results for the Disk and Linearly Source
For all MCNP simulations the geometry was set as follows; the radius of the contaminated disk sources was 4.00 cm, the collimator radius was 1.27 cm, the collimator length was 20.32 cm, and the surface of the contaminated medium was 50.00 cm from the collimator. In order to simulate the linear distribution of activity in the MCNP simulations, source disks of 60 Co were constructed at discrete positions along the axis of the distribution. Each disk had the same radius and extent from its position along the axis; however, the source probability for each position linearly decreased. As a standard, the maximum depth was divided by 200 to determine the number of source disks. Table 5 contains the prediction results for the PKMD and PKMLD models using the ratio of counts from the MCNP simulations. As demonstrated in Table 5, the GPDUA provides predicted depths consistently to within 10% discrepancy of the actual depth.
Table 5 predictes depths using the PKMD and PKMLD models. The ratio of surface counts was obtained from MCNP simulations where the contaminant source distribution is in aluminum. The value in parenthesis is the percent discrepancy between the predicted depth and the actual depth.
TABLE 5
Predicted Depth
Predicted Depth
Actual Depth
PKMD Model
PKMLD Model
(cm)
(cm)
(cm)
1.00
0.98 ± 0.02 (1.80%)
1.06 ± 0.02 (6.00%)
2.00
1.99 ± 0.05 (0.69%)
1.96 ± 0.04 (1.87%)
5.00
5.10 ± 0.12 (2.00%)
4.94 ± 0.10 (1.20%)
8.00
8.02 ± 0.18 (0.23%)
7.98 ± 0.17 (0.25%)
10.00
9.85 ± 0.23 (1.50%)
9.83 ± 0.20 (1.70%)
15.00
14.7 ± 0.34 (2.00%)
14.5 ± 0.30 (3.05%)
The GPDUA Input Requirements
The input requirements for the GPDUA are as shown in the flowchart of FIG. 8 . The intrinsic efficiency of the detector must be determined in order to adjust the gamma spectroscopy uncollided gamma counts into uncollided surface counts along the detector surface. The GPDUA iterates on the depth prediction until this ratio of counts is within tolerance of the calculated ratio. Prior knowledge of the material attenuation coefficient is necessary. The code does have a menu for selected common materials and isotopes. Use of the menu will call a subprogram to calculate material attenuation coefficients given the gamma energy. It is important to note that prior knowledge of the distribution must also be supplied to the code. The distribution can be assumed or all the distributions can be calculated for prediction depths.
The gamma spectroscopy provides the uncollided peak information. The gamma energy and counts under the uncollided peaks are important inputs for the GPDUA. The uncollided peak information from the gamma spectroscopy output must have the Compton continuum subtracted to ensure the peak counts are due to the uncollided gamma energy and not downscattered energies from higher energy gamma rays. Additionally, the counts must be adjusted for background. In general, the code is very flexible in that any collimator geometry should work. User inputs include the collimator length, collimator radius, and the distance from the contaminated surface to the face of the collimator.
From the results of MCNP simulations, the GPDUA models consistently predicts the depth of contamination to within 10% of the actual depth regardless of the type of contaminant distribution (point, disk, or linearly distributed). The narrow-beam approximation model produced poorer results; however, the model is based on ideal geometry and was not corrected for the gamma ray transport through portions of the lead collimators. A collimator thickness of 20.32 cm cannot be assumed to stop all gamma rays from entering the detector as suggested by the “good geometry” narrow-beam approximation model. As shown in FIG. 9, gamma rays enter the collimator through many directions since each source point can be considered an isotropic emitter. For the 1.33 MeV gamma ray from 60 Co, the mean free path through lead is approximately 1.5 cm. With a collimator length of 20.32 cm, this is approximately 13.5 mean free paths. As shown in FIG. 9, any gamma rays traveling along path A can be assumed to be 100% attenuated since N/N o =e −13.5 ≈1.4×10 −6 .
Any gamma rays that travel through partial lengths of lead less then ten mean free paths such as paths B and C should be assumed to contribute to the detector counts and is referred to as the “lead effect.” The shorter the path length through the lead, the more probable the gamma ray will pass through unattenuated.
As shown in Tables 2 and 3, the GPDUA predicted solutions are better for deeper depths. In fact, the narrow-beam approximation prediction approaches the same discrepancy as the GPDUA predictions for deep contamination depths. The reason for this can be seen in FIG. 10 . FIG. 10 depicts two cones at certain depths from the detector face. Each cone is drawn so that the surface of the cone travels a maximum of ten mean free path lengths through the lead collimator. The deeper contamination (cone A) results in a smaller solid angle from the isotropic point source to the detector surface and consequently even fewer gamma rays emitted will travel through the lead. As the contamination gets deeper, the gamma rays that travel through the lead must propagate through the full length of lead, resulting in more attenuation. Under the deep contamination conditions, the narrow-beam approximation model and the point kernel model for a point source will be in closer agreement.
If there is sufficient room when measuring the gamma rays in-situ, the further the detector/collimator is from the contaminated surface, the more the narrow-beam approximation model approaches the results of the point kernel models. A consequence of getting too far away is that the solid angle of gamma ray emission gets smaller and smaller to the detector surface. This will require longer count times in order to obtain sufficient number of gamma rays in the spectroscopic output to ensure a standard error of less than 1%. Additionally, the further the detector/collimator is from the contaminated surface, the greater the area of the assay, which defeats the purpose of having a collimator to focus the assay in order to map the contaminated surface. The point kernel models place no restrictions on the distance from the contaminated wall as evidenced in Tables 2 and 3.
Prediction models for the depth of radiological contaminants are presented. The models for point, disk, and linearly distributed contaminate distributions have been verified through MCNP simulations. The PKMP model for the point source contaminant has been validated by experiments. The analytic models in the GPDUA rigorously calculate the number of gamma rays that impact on the detector surface through a unique and innovative method using point kernel techniques on a physical detector. The systematic error from the point kernel models is consistently less then 10%.
There are two primary restriction to using the method in this paper. First, there must be two or more gamma rays emitted from the same isotope, or that a single gamma-emitting isotope must contain progeny that are in secular equilibrium with the parent nuclide. Second, prior knowledge of the source distribution is required or must be assumed. Prior knowledge can be obtained by traditional core sampling. Once this information is obtained from the core sampling, the method proposed in this research could be used to conduct more rapid and larger area surveys if the sampling depth distribution is assumed the same throughout the material.
Derivation of the Point Kernel Model for Point Particle (PKMP)
FIG. 11 depicts a cutaway view of the geometry showing the medium with a point source radioactive contaminant, the lead collimator, and the detector. In order to determine the response of a real detector with surface and volume from a point source the point kernel method is applied within the differential cone from the point source to the detector differential surface area dA, as shown in FIG. 6 . The total number of gamma ray counts impacting on the surface of the detector is determined by integrating the differential cone around the detector's surface.
The net counts on the surface of the detector were presented in equation (5) and point kernel was introduced in equation (6). As shown in FIG. 6, the differential area along the detector surface can be described as
dA[R ( x ),θ,ω]= r[R ( x ),θ] dr[R ( x ),θ] dω,
and since, r=R(x)tan θ and dr=R(x)sec 2 θdθ,
dA[R ( x ),θ,ω]= R ( x ) 2 tan θ sec 2 θdθω. (11)
Substituting equations (11) and (6) into equation (5), the general solution becomes, N ( E ) = N ′ ( E ) ɛ ( E ) = A o tY ( E ) ∫ Detector
Surface exp [ - μ ( E ) R ( x ) sec θ ] 4 π [ R ( x ) sec θ ] 2 R ( x ) 2 tan θsec 2 θ θ ω ,
N ( E ) = N ′ ( E ) ɛ ( E ) = A o tY ( E ) 4 π ∫ Detector
Surface exp [ - μ ( E ) R ( x ) sec θ ] tan θ θ ω ,
N ( E ) = N ′ ( E ) ɛ ( E ) = A o tY ( E ) 2 ∫ 0 θ max ( x ) exp [ - μ ( E ) R ( x ) sec θ ] tan θ θ . ( 12 )
The solution of equation (12) is separated into three integrals over the polar angle to accommodate the different response functions, G(E,R(x),θ), in the differential cones. As shown in FIG. 11, the first integral is over the polar angles zero to α(x) and the second integral over the polar angles λ(x) to β(x) and the third integral is over the polar angles β(x) to ω(x). The first integral defines the transport of gamma rays through the medium and collimator opening without any transport through the lead collimator. The second integral defines the transport of gamma rays through the medium and partially through the lead collimator. The third integral defines the transport of gamma rays through the medium and the entire collimator.
The general solution can then be defined as, N ( E ) = A 0 tY ( E ) 2 ( I 1 + I 2 + I 3 ) ( 13 )
where I is of the general form, I = 4 π ∫ θ min ( x ) θ max ( x ) G ( E , R ( x ) , θ ) A ( R ( x ) , θ ) θ . ( 14 )
The results are I 1 = ∫ 0 α ( x ) exp [ - ( μ m ( E ) x + μ air ( E ) ( D + D C ) ) sec θ ] tan θ θ , ( 15 ) I 2 = ∫ α ( x ) β ( x ) exp { - [ μ m ( E ) x sec θ + μ air ( E ) ( R C csc θ - x sec θ ) + μ Pb ( E ) ( ( x + D + D C ) sec θ - R C csc θ ) ] } tan θ θ , ( 16 ) I 3 = ∫ β ( x ) χ ( x ) exp { - [ μ m ( E ) x + μ air ( E ) D + μ Pb ( E ) D C ] sec θ } tan θ θ ( 17 )
where α ( x ) = Tan - 1 R C ( x + D + D C ) ( 18 ) β ( x ) = Tan - 1 R C x + D ( 19 )
and, χ ( x ) = Tan - 1 R D ( x + D + D C ) . ( 20 )
The Parameters;
μ m (E),μ air (E), and μ Pb (E) are the attenuation coefficients for the material, air, and lead respectively, for gamma energy E,
R C and R D are the radius of the collimator and detector respectively,
D is the distance from the contaminated surface to the collimator, and
D C is the collimator length.
The model is obtained by taking the ratio of equation (13) for the high and low energy gamma rays, E y1 and E y2 , emitted by the isotope. The final form of the model for equal counting times is N ( E γ 1 ) N ( E γ 2 ) = Y ( E γ 1 ) ( I 1 1 + I 2 1 + I 3 1 ) Y ( E γ 2 ) ( I 1 2 + I 2 2 + I 3 2 ) ( 21 )
where the superscript on the integrals I 1 , I 2 , and I 3 represent that integral being evaluated with the attenuation coefficients of the corresponding gamma ray energy.
A Gamma Penetration Depth Unfolding Algorithm (GPDUA) written in FORTRAN code solves equation (21) by iterating on the depth variable, x, until the right hand side is within in a specified tolerance of the left hand side. The ratio is obtained from the MCNP uncollided peak counts or the gamma spectroscopy uncollided peaks after adjusting these counts for the Compton continuum and the intrinsic efficiency.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A non-destructive method and apparatus which is based on in-situ gamma spectroscopy is used to determine the depth of radiological contamination in media such as concrete. An algorithm, Gamma Penetration Depth Unfolding Algorithm (GPDUA), uses point kernel techniques to predict the depth of contamination based on the results of uncollided peak information from the in-situ gamma spectroscopy. The invention is better, faster, safer, and/cheaper than the current practice in decontamination and decommissioning of facilities that are slow, rough and unsafe. The invention uses a priori knowledge of the contaminant source distribution. The applicable radiological contaminants of interest are any isotopes that emit two or more gamma rays per disintegration or isotopes that emit a single gamma ray but have gamma-emitting progeny in secular equilibrium with its parent (e.g., 60 Co, 235 U, and 137 Cs to name a few). The predicted depths from the GPDUA algorithm using Monte Carlo N-Particle Transport Code (MCNP) simulations and laboratory experiments using 60 Co have consistently produced predicted depths within 20% of the actual or known depth. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to prolonging the life of refractory brick walls, and more particularly to a method of straightening collapsed portions of the flue walls of a carbon anode ring furnace.
In the process of aluminum reduction, carbon anodes are used in the reduction process. These carbon anodes are generally formed by compacting a calcined petroleum coke aggregate and a pitch binder into a self-supporting block which is subsequently heat-treated in a large ring furnace. The ring furnace includes a number of flues each comprising a pair of spaced vertical walls constructed of refractory brick formed of silicon carbide or the like. Extending between the confronting surfaces of the walls of the flue are a number of baffles also constructed of refractory brick. These baffles direct the flow of a combustible gas mixture in a predetermined path through the flue. Temperatures as high as 1300° C. exist in the hotter areas of the flue, for example, adjacent the upper portion thereof at the point of introduction of the combustible gas mixture. After operation of the furnace for a number of cycles over a period of time at such high temperatures, portions of the flue walls frequently collapse inwardly, particularly in the "hot spots" adjacent the gas inlets where the walls are generally unsupported by the baffles. Such wall collapses undesirably reduce the cross-sectional area of the gas flow path which, in turn, considerably reduces the efficiency of the furnace. Ultimately, of course, the entire flue walls must be torn down and replaced at considerable expense in terms of both material and labor costs. Moreover, operational efficiency of the aluminum reduction facility as a whole can be impaired by frequent furnace shutdowns for replacement of the collapsed flue walls.
SUMMARY AND OBJECTS OF THE INVENTION
In view of the aforementioned problems in the prior art caused by the localized collapses of the flue walls of the carbon anode ring furnace, it should be apparent that there still exists a need in the art to overcome such problems and extend as much as possible the operational life of the flue walls of the furnace. It is, therefore, a primary object of this invention to provide a novel method of substantially prolonging the operational life of the carbon anode ring furnace.
More particularly, it is an object of this invention to provide a simple and economical method for the in situ straightening of collapsed flue walls of a ring furnace.
Still more particularly, it is an object of this invention to provide a method for urging apart the inwardly collapsed flue walls of a furnace in a controlled manner to avoid damage to the walls.
Another object of this invention is to provide a jacking apparatus which is adapted to be manipulated into position adjacent a collapsed wall portion and operated to selectively urge the displaced refractory bricks back into the plane of the wall.
Briefly described, these and other objects of the invention are accomplished in accordance with its apparatus aspects by providing a fluid actuated jack which is operatively connected by a flexible hose to a fluid pump, such as a manually operated hydraulic pump. An elongated rigid handle is connected to the jack for manipulating the same into a predetermined orientation and position with respect to the collapsed wall portion according to the method of this invention. The oppositely disposed reaction surfaces of the jack which confront the flue walls are of substantially different areas so that the force per unit area applied respectively to the refractory bricks of each confronting flue wall is significantly different. A reaction surface area differential of about 36 sq. in. to 1 sq. in. has been successfully used, but such ratio is not intended to limit the present invention since other area ratios could be utilized as well.
The method aspects of the invention are accomplished by removing the top portion of the furnace to expose the interspace between the flue walls. The jack is then inserted between the walls adjacent a collapsed portion with the larger reaction surface area oriented to confront several bricks of the wall having the lesser deformation, that is, the more planar surface. The smaller reaction surface area of the jack is arranged to confront a single brick of the wall having the greater extent of deformation, preferably at or near the outermost extent of the collapsed wall portion.
Expansion of the jack by means of the manual hydraulic pump urges the displaced brick more into alignment with the plane of the wall and, thereafter, the jack is retracted. By means of the elongated handle, the jack is successively moved into a number of preselected positions about the deformation zone and extended and retracted to reduce the same. In a preferred technique of carrying out the method of the invention, the preselected positions are disposed along substantially circular paths of diminishing radii about the deformation zone in a manner to gradually urge the displaced bricks back into position and to avoid applying such a force to an individual brick that it will be dislodged from the wall and, thus, form a hole therein.
When the wall has been substantially straightened in accordance with the foregoing process, the jack will be located closely adjacent the former point of maximum deviation of the deformation zone, i.e., near the center of the collapsed wall portion. Prior to retracting the jack at this final location, a "tie" brick is cut to a length closely approximating the distance between the walls and inserted at a point adjacent the jack. Thereafter, the jack is retracted by bleeding the hydraulic cylinder of the pump and the walls will move inwardly to a slight extent and engage the tie brick end faces. The tie brick maintains the walls spaced apart in substantially their original spacing and has no appreciable effect on the flow of combustible gases through the flow path between the flue walls. Advantageously, a high temperature setting mortar is pointed into any cracks or holes in the wall to provide it with added strength and resistance to further collapses.
With these and other objects, advantages and features of the invention that may become hereinafter apparent, the nature of the invention will be more clearly understood by reference to the following detailed description of the invention, the appended claims and to the several views illustrated in the attached drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side elevation view of the flue of a carbon anode ring furnace showing the wall areas of greatest susceptibility to collapse;
FIG. 2 is a broken cross-sectional view of the furnace flue taken along line 2--2 of FIG. 1 showing portions of the walls which have collapsed inwardly;
FIG. 3 is a broken cross-sectional view of the furnace flue taken along line 2--2 of FIG. 1 showing the flue walls after they have been straightened utilizing the apparatus and method of the present invention;
FIG. 4 is a perspective view showing an embodiment of the apparatus of the present invention;
FIG. 5 is an end view of a collapsed wall portion of the flue walls taken along line 5--5 of FIG. 2 and showing the apparatus of FIG. 4 in position for straightening the collapsed wall portion; and
FIG. 6 is a partial side elevation view of the flue wall showing a circular pattern for positioning the jack reaction surfaces according to the wall-straightening method of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and more particularly to FIG. 1 wherein there is illustrated in cross-section a flue 10 of a carbon anode ring furnace. The flue 10 comprises a pair of spaced walls 12 and 14 (FIG. 2) constructed of a plurality of refractory bricks 16 composed, for example, of silicon carbide. Such refractory bricks are well-known in the art, one common type particularly suited for constructing the furnace flue walls being designated Type S brick and having a length of nine inches, a width of four and one half inches and a height of three inches. The upper and lower surfaces of the Type S brick are provided with a curvilinear tongue and groove interlocking arrangement, the tongue and groove having a radius of about 9/16 inch and 11/16 inch respectively. The walls 12, 14 may be constructed using the Type S brick in a conventional manner with the grooves arranged on the upwardly facing sides of the bricks of a layer in interlocking relationship with the downwardly facing tongues of a superposed layer of bricks. For purposes of the description herein, the height and length dimensions of a typical flue are approximately 11 feet by 11 feet with a wall spacing of about 6 inches between the confronting wall surfaces.
The top 18 of the flue is enclosed along its entire length except for a number of gas inlet openings 20 through which natural gas or the like is introduced for combustion. To support the combustion of the natural gas, air is drawn into the furnace at an air inlet 22 and the products of combustion are discharged at exhaust outlet 24. The direction of the flow of hot gases between the walls is controlled by a plurality of baffles 26 which direct the gas flow in a generally W-shaped path from inlet 22 to outlet 24 as shown by the arrows in FIG. 1.
The elliptical areas 28 of the flue wall 12 shown in broken lines in FIG. 1 denote the furnace "hot spots " where temperatures as hot as 1300° C. can be reached and where the greatest susceptibility to collapse exists in the flue walls. As is apparent, these areas 28 are situated closely adjacent the upper portion of the flue and coincide generally with the locations of the gas inlet openings 20. It is to be understood, however, that wall collapses or deformation zones could occur in other areas of the flue walls, including the central and lower portions thereof.
In FIG. 2 there is shown a view looking from the top 18 of the furnace down into interspace between the flue walls 12, 14 where a portion of each of the walls has collapsed inwardly, creating deformation zones 30, 32. Not only do the deformation zones 30, 32 result in a reduced cross-section 34 which restricts the flow of gases through the flue, but they also threaten the integrity of the entire wall and, therefore the operability of the furnace. Thus, it is imperative that the deformation zones be eliminated quickly and economically and with as little damage as possible to the walls themselves. In accordance with the present invention, this is accomplished by use of the apparatus shown in FIG. 4 and designated generally by reference numeral 34.
The apparatus comprises a hydraulic jack 36 having a cylindrical body 38 which houses telescoping pistons 39. At the opposite ends of the jack are disposed reaction surfaces 40, 42 of substantially different cross-section areas and elongated rigid handle 44 is securely affixed to the jack body 38 for manipulating the jack 36 into position between the flue walls. A long flexible hose 46 is operatively connected at one end to the jack for supplying hydraulic fluid under pressure to the jack and the other end of the hose is connected to a hydraulic pump, such as manually operated pump 48. The pump 48 is of conventional construction, therefore, its structure and operation need not be described in great detail except as follows. The hydraulic cylinder 49 of the pump 48 is provided with a bleed valve 50 which may be manually controlled to relieve the pressure developed in the jack 36 to thereby retract the same. Also, the pump may be conveniently mounted, if desired, on a base plate 52 to aid in the handling and use thereof. A jack and pump combination capable of developing a pressure of about 6,000 psi is suitable for use in the present invention. An area ratio of about 36 sq. in. to 1 sq. in. between the reaction surfaces 40, 42 and a handle 44 having a length of about eight feet have been found to be particularly advantageous for flue walls of the previously mentioned dimensions, although various other area ratios and handle lengths could be utilized.
In FIG. 5, the jack 36 is shown positioned for straightening the deformation zone 30 in accordance with the method of the invention which includes the steps of (1) inserting the jack 36 between the walls 12, 14 into a preselected position adjacent the deformation zone 30 with the smaller reaction surface 42 in confronting relation with a single brick of the deformation zone of wall 12 and the larger reaction surface 40 confronting at least two bricks of the opposing wall 14; (2) extending the jack 36 to engage the walls 12, 14 with the reaction surfaces 40, 42; (3) applying controlled, oppositely-directed forces to the bricks by operating the hydraulic pump to thereby reduce the deviation of the bricks 16 from the plane of the walls; and (4) retracting the jack from engagement with the walls. Since the greater force per unit area is applied at the single brick of the deformation zone, it will tend to move to a greater extent than the bricks of the confronting wall against which a lesser force per unit is applied. By successively moving the jack 36 into a number of predetermined positions about the deformation zone and repeating the aforementioned steps, reduction of the deformation zone can be readily accomplished.
FIG. 6 illustrates an exemplary pattern of preselected positions about the deformation zone at which the jack may be advantageously located with a minimum danger of dislodging a brick from the wall. Preferably, the smaller reaction surface 42 is centrally located on the bricks at the successive positions a-r which are disposed along substantially circular paths 54, 56, 58 of diminishing radii about the center x of the deformation zone 30. As the jack is actuated at the successive positions a-r, the bricks adjacent an individual position will also be forced back into the plane of the wall by reason of the interlocking arrangement of the tongues and grooves on the upper and lower surfaces of the bricks. It is to be understood, however, that, depending upon the extent of the deformation zone, the jack need not necessarily be sequentially located at all the positions shown in FIG. 6. Some positions may be omitted and the jack may be moved in counterclockwise circular paths rather than clockwise paths as shown. It will be appreciated that the advantage of moving the jack from the periphery of the deformation zone toward the center thereof is that a lesser force is required to reduce the deformation zone than if the jack were initially located at the center of the zone at the point of maximum deviation.
After the deformation zone has been substantially completely reduced, the spacing between the walls 12, 14 adjacent the point of maximum wall deviation x is measured with the jack 36 still in its extended position. A tie brick 60 (FIG. 3) is then cut to a length equivalent to the spacing, inserted into position adjacent the jack 36 and, thereafter, the jack is retracted to permit the walls to move slightly inwardly and engage the end faces of the tie brick. Thus, as shown in FIG. 3, the deformation zone can be substantially eliminated and the only added resistance in the gas flow path is a single tie brick. If necessary, any gaps or cracks in the walls are pointed with a high temperature setting mortar to further strengthen the walls.
Although only preferred embodiments of the method of the present invention are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention. | A method of prolonging the life of a carbon anode ring furnace is disclosed wherein portions of the confronting refractory brick flue walls of the furnace which have partly collapsed can be readily straightened. The refractory bricks of the collapsed portion of a flue wall are urged back into the plane of the wall by interposing a hydraulic jack between the closely spaced flue walls and actuating the jack to apply opposing forces to the wall. The jack is positioned and actuated in a number of locations corresponding to a predetermined circular pattern about a deformation zone to successively reduce the deviation of the bricks of the deformation zone. A tie brick is thereafter inserted between the walls to maintain them in their normal spaced relation. | 5 |
This application is a continuation of application Ser. No. 08/805,750, filed Feb. 25, 1997, now abandoned, which is a continuation of application No. 08/045,690, filed Apr. 14, 1993, now abandoned, which is a divisional of U.S. patent application Ser. No. 07/685,732, filed Apr. 16, 1991, now U.S. Pat. No. 5,225,852, issued Jul. 6, 1993.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transport means for transporting a recording material and a recording apparatus having the transport means.
2. Description of the Related Art
In recording apparatus, such as a copying machine or a printer, a recording material is generally transported from a sheet feeding station, such as a cassette, through an image forming station and to a sheet eject station. In such cases, conveyance of the recording material is controlled at a predetermined timing as the recording material is led from the sheet feeding station to the image forming station, recorded with an image, and ejected. It is necessary for the transport of the recording sheet material to be precise, especially since the timing of transport from the feed of the recording material to the image recording location influences the image recording position on the recording material. Furthermore, if the conveyance speed of the recording material during image recording is not kept constant, the magnification of the image varies and the image recorded on the recording material is partially expanded and contracted. Slippages among images recorded by the different recording heads therefore occur, especially in the case of an image recording apparatus in which a plurality of image recording heads are disposed side by side. In the case of a color image recording apparatus, such phenomenon results in color slippage and color irregularity, which are critical defects for high-quality image forming. Therefore, it is necessary to precisely drive a transport means and exactly transmit the conveying force of the transport means to the recording material in order to avoid the above problems.
With the above problems in view, various kinds of transport systems have been suggested. For example, a conventional conveyor system conveys a recording material by a pair of rollers and regulates the conveying direction by a guide. Since such a conveyor system feeds the recording material out by pressure between the rollers, the conveying force thereof is strong and the conveyance is reliable and simple. However, the pair of rollers must be placed with the minimum length of a recording material to be used in mind, and such a conveyor system is unsuitable for the conveyance of, for example, postcard-sized and visiting-card-sized recording materials. Furthermore, the system cannot be used in an apparatus, such as an electrophotographic apparatus, where the system cannot be allowed to contact the recording surface of the recording material at any point between the transfer of an image on the recording material by a drum and the fixing thereof.
Another method transports a recording material by nipping and pulling the leading edge of the recording material by a gripper. In this case, once the gripper nips the recording material, the conveying force is surely strong and reliable. However, the mechanism is complicated. Furthermore, the transport system is undesirable in that it is difficult to time the nip of the leading edge of the recording material by the gripper and a mark from the gripper is made on the recording material.
A still further method uses a fan or the like to suck a recording material from the rear of an endless belt with many holes, adhere the recording material to the belt by negative pressure generated by the suction, and convey the recording material. Although this method has been used to convey the recording material prior to fixing of a toner image in electrophotography, since the conveyance is executed by only the suction from the rear, the conveying force is small. Furthermore, it is likely that the surface of the belt will be soiled since dust and toner in the apparatus are also sucked.
In order to solve the above problems, a transport device using an electrostatic suction method shown in FIG. 1 has been suggested by the applicant of the present invention for a color ink jet recording apparatus.
The color ink jet recording apparatus will now be schematically described with reference to FIG. 1. A scanner station 101 reads an image from a document 103 laid on a document table 102 and converts the image into electrical signals and a printer station 201 records on a recording material 203 in accordance with the converted electrical signals. In the scanner station 101, a document scanning unit 104 scans in the direction indicated by the arrow A and reads the image from the document 103. Reference numerals 105, 106 and 107 denote an exposure means, a rod array lens and an equivalent magnification color separation line sensor (color image sensor), respectively. When the lamp of the exposure means 105 is lit during the scanning by the document scanning unit 104 and document 103 is irradiated, the light reflected by document 103 is focused onto the color image sensor 107 through the rod array lens 106, and image information on the document 103 is read for respective colors and converted into digital signals.
In the printer station 201, a cassette 202 feeds recording sheets 203. The feeding operation of the recording sheets 203 stored in the cassette 202 is performed by a feeding roller 202A. The feeding roller 202A feeds recording sheets 203 one by one from the cassette 202 and through conveying rollers 202B. A resist roller 204 temporarily stops the recording sheets 203 at an outlet thereof and then feeds out the recording sheet 203 onto an endless belt 211 in a belt conveyer station 210 according to the document read timing. A recording head unit 220 is composed of a plurality of recording heads 221 for jetting different inks, that is, a head BK for a black ink, a head Y for a yellow ink, a head M for a magenta ink and a head C for a cyan ink. The full-line heads 221 each have an unillustrated ink jet opening disposed corresponding to the recordable width of the sheet and placed at a predetermined space from the endless belt 211.
A recovery cap means 230 is sealed on the jetting openings of the recording heads 221 at non-recording time and recovery time from defective jetting. While a recording operation is performed by the recording head unit 220, the recording head unit 220 and the recovery cap means 230 are maintained in the state shown in FIG. 1, respectively. Reference numerals 240 and 250 denote an eject station for ejecting the recorded sheet 203 after fixing, and an eject tray.
Furthermore, reference numerals 202B, 202C, 202D and 202E denote a conveying roller, a manual supply table, a supply roller and an eject roller, respectively, and reference numerals 202F and 202G denote platens.
The belt conveyor station 210 will now be described in detail. The endless belt 211 (referred to as a conveyor belt hereinafter) is looped between a driving roller 212 and a driven roller 213. A charging roller 214 charges the belt 211 so as to adhere the recording sheet 203 onto the belt 211, a cleaner member 215 is disposed on the exit side of the belt conveyor station 210 and cleans the belt 211 soiled by ink as described below, and a platen 216 is disposed at the rear of the conveyor belt 211 and opposite to the recording head unit 220. A conductive presser member 217 for pressing the recording sheet 203 onto the belt 211 and electrically grounding the recording sheet 203 is mounted on the belt 211 on the entrance side of the belt conveyor station 210.
FIG. 2 shows the construction of the conveyor belt 211. Reference numeral 211A denotes an insulating layer made of an insulating material and which forms the surface of the conveyor belt 211. A conductive layer 211B made of an elastic and conductive material, for example, a conductive rubber or the like, is below the insulating layer 211A. An indented layer 211C is attached to the inside of the conductive layer 211B and has a repeating dent structure.
In the color ink jet recording apparatus having such a construction, the printer station 201 performs a recording operation based on the image information read from the document by the scanner station 101. Then, the recording sheet 203 fed out from the cassette 202 is fed into the belt conveyor station 210 in the timing in accordance with the document reading after being registered by the resist roller 204. The ink is jetted onto the recording sheet 203 at an appropriate timing for recording heads 221 so as to perform a recording operation. Then, the recorded sheet 203 is fixed and ejected onto the eject tray 250 through the eject station 240. A sheet detection sensor 261 is disposed immediately in front of the resist rollers 204 and a sheet detection sensor 262 is disposed in the eject station 240. The resist rollers 204 start rotating in response to a sheet detection signal from the sheet detection sensor 261 or in response to a signal from the scanner station 101 in synchronization with the sheet detection signal, and the resist rollers 204 then feeds the recording sheet 203 into the belt conveyor station 210. The sheet detection sensor 262 confirms ejection of the recording sheet 203, and determines that jamming has occurred when the sheet detection sensor 262 does not detect recording sheet 203 within a predetermined time from when the sheet detection sensor 261 has detected recording sheet 203.
However, because of the sequence of operations in the above recording apparatus, if the recording material 203 jams between resist rollers 204 and the recording head unit 220 in the printer station 201, a recording signal has been already transmitted to each of the recording heads 221, and it is therefore likely that the ink will be jetted onto the conveyor belt 211 in the belt conveyor station 210. Furthermore, since the paper jam is not recognized in this state until the recording sheet 203 reaches the next sheet detection sensor, for example, the ejection detection sensor 262, the recording operation is likely to continue. In this case, large amounts of ink are jetted onto the conveyor belt 211. The conveyor belt 211 is cleaned by the cleaner member 215, which normally does not operate during a recording operation. Thus, during a recording operation a cleaning member thereof (for example, a blade member) is not in contact with the conveyor belt 211. This is because it is necessary to minimize the torque loaded on the conveyor belt 211 during the recording operation since high precision is necessary for the drive of the conveyor belt 211, as described above. Therefore, if the above accident happens during the recording onto a long recording sheet of, for example, A3 size, it is likely that the part of the conveyor belt 211 where the ink is jetted will pass the position of the cleaner member 215 and move downstream, and that the ink adhered onto that part will be transferred onto the charging roller 214 and soil the charging roller 214.
Furthermore, it is also likely that the rear surface of the recording sheet will become soiled since the ink is transferred again from the charging roller 214 onto the conveyor belt 211 during the next recording operation.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a transport means capable of achieving a high-quality recording without any slippage of the recording medium, and a recording apparatus having the transport means.
Another object of the present invention is to provide a transport means capable of preventing ink from being jetted thereon when a recording material jams, and a recording apparatus having the transport means.
A further object of the present invention is to provide a transport means capable of properly cleaning the soil resulting from adhesion of ink and the like thereon, and a recording apparatus having the transport means.
A still further object of the present invention is to provide a recording apparatus capable of minimizing the amount of ink jetted onto a conveyor belt when jamming or the like happens in a belt conveyor station in order to solve the above problems.
In one aspect of the invention, there is provided a transport device for use in a recording apparatus including a recorder for recording onto a recording material and detection means for detecting recording material. The transport device includes a conveyor belt having a first conductive or semiconductive layer discriminable from a recording material by the detection means, a second insulating layer below the first layer and a third conductive layer below the second layer. A drive means drives the belt and a charging means charges the belt as it is driven.
In a second aspect of the invention, there is provided a recording apparatus in which a recording material is conveyed by an endless charged belt and a recording head records on the recording material in a predetermined recording region. Detection means detect a jam of the recording material in the recording region. The conveyor belt includes a first layer made of a conductive or semiconductive material having a thickness of 5 to 30 μm and a volume resistivity value lower than a predetermined value and which is discriminable from a recording material by the detection means. A second insulating layer is below the first layer and a third conductive layer is below the second layer. Cleaning means are disposed downstream of the recording region and in contact with the conveyor belt to clean the surface of the conveyor belt.
In still another aspect of the invention, there is provided a recording apparatus for performing recording onto a recording material by means of an ink jet head for jetting ink onto said recording material. Detection means detect a jam of the recording material, transport means transports the recording material, cleaning means clean ink from the transport means, and control means controls a cleaning operation by the cleaning means in accordance with the amount of ink jetted from the ink jet head after detection of the jam by the detection means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing the construction of a color ink jet recording apparatus which has been suggested by the applicant of the present invention;
FIG. 2 is a view showing the construction of a conveyor belt of the color ink jet recording apparatus;
FIG. 3 is a side view showing the construction of an embodiment of the present invention;
FIG. 4 is a side view showing the construction of a conveyor belt according to the present invention;
FIGS. 5, 6 and 7 are flowcharts of cleaning operations;
FIG. 8 is a block diagram of an ink jet recording apparatus to which a preferred embodiment is applied; and
FIG. 9 is a look-up table stored in memory.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail and specifically with reference to the drawings.
FIG. 3 shows an embodiment to which the present invention is applied. The main parts concerned with a recording operation, including a recording head unit 220 and a belt conveyor station 210, will first be described in detail. Upper and lower guide plates 205A and 205B lead a recording sheet fed out from resist rollers 204 onto a conveyor belt 211. Electrode springs 214A are disposed at both ends of charging roller 214 so as to press charging roller 214 against conveyor belt 211, and electrode springs 214A are connected to an unillustrated high voltage power supply. At the same time that recording sheet 203 reaches the resist rollers 204 and conveyor belt 211 starts to be driven by a drive motor 102M (shown in FIG. 8), a voltage of several KV is applied to charging roller 214 via electrode springs 214A from the high voltage power supply, thereby charging the surface of the conveyor belt 211.
Recording sheet 203, which is fed out from resist rollers 204 in accordance with the timing of the document reading, comes into contact with the charged conveyor belt 211. Since charges each having a phase reverse to that of conveyor belt 211 are attracted to the belt 211 due to the polarization on the recording sheet 203, the recording sheet 203 is thereby adhered to the conveyor belt 211. Then, the recording sheet 203 is pressed against the belt 211 by conductive presser member 217 and is adhered to the belt 211 even more firmly since the presser member 217 is grounded.
The recording sheet 203, held on the conveyor belt 211 as described above, is led to recording region P along a platen 216 whose flatness is approximately 0.05 to 0.10, and recording on the recording sheet 203 is performed by the recording head unit 220 at a recording region P. A head holder 222 fixes and holds a plurality of recording heads 221, and reflective optical sensors 223 and 224 are disposed at both ends of the head holder 222, that is, at the upstream and downstream positions of the head holder 222 along the conveyor belt 211, respectively. Sensors 223 and 224 detect the presence of the recording sheet 203 on the conveyor belt 211 based on the reflective light from the recording sheet 203 and the conveyor belt 211, and are referred to as a first sensor 223 and a second sensor 224 hereinafter. The detection operation thereof will be described below.
Two positioning pins 225 are disposed in the front and rear portions at each side of the upper surface of the platen 216 along the conveyor belt 211, and determine the vertical position of the recording head unit 220. By having the lower surface of head holder 222 abut against the upper surfaces of the positioning pins 225, a predetermined space is maintained between ink jetting surfaces 221A of the recording heads 221 and the recording sheet 203.
After recording sheet 203 is recorded on. In the recording region P, it is conveyed in the direction A by the conveying force of the conveyor belt 211, separated from the conveyor belt 211 by a driving roller 212 by curvature separation, advanced along a guide plate 241, fixed at the next fixing position, and ejected.
A cleaner member 215 is placed so as to be in contact with conveyor belt 211 downstream from where recording sheet 203 is separated from conveyor belt 211, and has a blade 243 mounted to a bracket 242 and an ink absorber 245 mounted to another bracket 244, which are held apart from the surface of the conveyor belt 211 as shown in FIG. 3 when a normal recording operation is performed. This is because the drive of the conveyor belt 211 influences the recording quality and must be precise as described above. Therefore, the cleaner 215 is separated from conveyor belt 211 during the recording operation so that any unnecessary load is not borne by conveyor belt 211. As described below, the cleaner member 215 is in contact with the conveyor belt 211 so as to perform a cleaning operation only when it is necessary to clean the conveyor belt 211.
The conveyor belt 211 will now be described in detail ith reference to FIG. 4. Although the construction of an nsulating layer 211A, a conductive layer 211B and an indented layer 211C is not different from that shown in FIG. 2, a discrimination detection layer 261 is further mounted on the insulating layer 211A in this embodiment. The discrimination detection layer 261 facilitates differentiation by the first and second sensors 223 and 224 between the surfaces of the recording sheet 203 and of the conveyor belt 211. It has a volume resistivity value of less than 10 13 Ωcm, and preferably, of approximately 10 14 to 10 17 Ωcm, and is made of a conductive or semiconductive material, and maintains a conveyance thickness error of less than ±20 μ in consideration of the recording precision. In this embodiment, the discrimination detection layer 261 is formed by applying, for example, an application agent including pigment of a color having a different reflectance from that of recording sheet 203, a urethane or silicon black paint in this embodiment, onto the insulating layer 211A by the thickness of 5 to 30 μ, and preferably, approximately 10 μ, by using a spray or the like. In addition, the insulating layer 211A itself may be of the above color. However, if the insulating layer 211A is, for example, black or the like, since carbon or the like is generally combined, the resistance value of the insulating layer 211A is lowered and its function of adhering the recording sheet 203 is inhibited.
In the recording apparatus having such a structure, recording on recording sheet 203 is performed in the recording region P only when the recording sheet 203 is normally conveyed by the conveyor belt 211. Therefore, the ink is not inadvertently jetted onto the conveyor belt 211. Furthermore, since the conveyance of the recording sheet 203 is monitored by the first and second sensors 223 and 224, if the recording sheet 203 is not detected once a predetermined amount of time has passed after the resist rollers 204 start to rotate, or if the detection is continued, it is determined that a jam has occurred and the sequence of operations related to the recording is stopped.
If a jam occurs upstream of the first sensor 223, since the recording operation by the recording head 221 is stopped, it is unlikely that the conveyor belt 211 will be soiled by the ink. If the jam occurs between the first sensor 223 and the second sensor 224, the ink is likely to be jetted onto the conveyor belt 211 within the range indicated by l in FIG. 3. However, since the second sensor 224 immediately detects that the recording sheet 203 has not passed and is thus jammed, the conveying operation of the belt conveyor station 210 is stopped. The part of the conveyor belt 211 which is soiled by the ink has not passed the position of the cleaner member 215. Therefore, when the conveyor belt 211 is stopped after the above sequence of operations, the blade 243 is brought into contact with the surface of the conveyor belt 211 and the conveyor belt 211 is again driven, and the ink on the conveyor belt 211 is swept aside by the blade 243. Subsequently, the blade 243 is separated from the surface of the conveyor belt 211. The ink absorber 245 is then brought into contact with the surface of the conveyor belt 211 so as to be in contact with the ink, which was swept on the conveyor belt 211 by the blade 243, for a predetermined time, and the ink is absorbed by the absorber 245. After that, the cleaner member 215 is separated from the surface of the conveyor belt 211 and returned to the initial position thereof, so that a normal recording sequence is performed again. Although the conveyor belt 211 from which the ink is thus swept away is charged again by the charging roller 214, since the ink is entirely removed from the conveyor belt 211, no ink is transferred onto the charging roller 214.
In the above embodiment, the jam caused at the region opposite to the recording heads is detected by sensors 223, 224 disposed in the front and at the rear of the recording head unit, respectively. However, the detection method is not limited to this embodiment. For example, if other sensors are mounted between the recording heads so as Lo subdivide the jam position, it is possible to further narrow the region where the ink is incorrectly jetted when a jam occurs and to facilitate the sweep of ink from the conveyor belt.
Furthermore, in this embodiment, it is preferable that the volume resistivity value of the insulating layer 211A of the conveyor belt 211 be more than 10 13 Ωcm and that the volume resistivity value of the conductive layer 211B be less than 10 8 Ωcm. An appropriate thickness of the insulating layer 211A is approximately 50 to 200 μm.
The cleaning operation of the cleaner member 215 for the conveyor belt 211 will now be described in more detail with reference to FIGS. 3 and 5 to 9.
Referring to FIG. 3, the recording sheet 203 is conveyed from right to left at a constant recording speed by the conveyor belt 211. However, if the recording sheet 203 is not conveyed and does not reach the eject tray 250 because of some abnormality in the middle of the conveyance, a display of a sheet jam is made and the eject sensor 262 initiates a pause in the recording operation. The user removes the jammed sheet, and, after disposing of the sheet jam, the cleaning operation is executed by automatically or manually operating the cleaning device before engaging in additional recording operations.
The cleaner member 215 in this embodiment will be described with reference to FIG. 3. The blade 243 is shaped in the form of a plate or a chip made of polyurethane rubber and is fixed to attachment plate 243A. The attachment plate 243 is fixed to the bracket 242 rotatably mounted on a rotary pin 133 which is disposed in parallel with driving roller 212. The absorber 245 is fixed to a case 245A which is fixed to the bracket 244 rotatably mounted on the rotary pin 133. Furthermore, a plunger angle (not shown), having an electromagnetic plunger 143 (shown in FIG. 8) for contacting with and separating the blade 243 from the belt 211 and an electromagnetic plunger 144 (shown in FIG. 8) for contacting with and separating the absorber 245 from the belt 211, is mounted to a front arm (not shown) and a rear arm (not shown) to which the roller 212 is attached. A drive arm (not shown) for transmitting a stroke of the plunger 143 to the bracket 242 and a drive arm (not shown) for transmitting a stroke of the plunger 144 to the bracket 244 are rotatably mounted to a support pin (not shown) fixed to the plunger angle. Extension springs (not shown) are hung between the bracket 242 and the plunger angle and the bracket 244 and the plunger angle, respectively, so that the blade 243 and the absorber 245 are separated from the belt 211 when the plungers 143 and 144 are not pulled.
When the the blade 243 is pressed against the conveyor belt 211 by driving the plunger 143, a wiper edge of the blade 243 securely abuts against conveyor belt 211 across its entire width. In this state, conveyor belt 211 is driven by driving roller 212, and the unnecessary ink on conveyor belt 211 is forced against the blade 243 and swept away from conveyor belt 211. In this embodiment, blade 243 is pressed against the portion of conveyor belt 211 that is wrapped around driving roller 212 and which has little resilience and is hard to be transformed by pressure. The blade attachment surface is disposed almost vertically so that the ink swept by the blade 211 promptly drips from the blade 211.
The disposed ink is gathered in an ink receiver 123. An absorber (not shown) may be mounted in the ink receiver 123 to receive the ink in order to prevent the inside of the apparatus from being soiled. Although most of the disposed ink naturally dries and evaporates, another unillustrated tank may be mounted to receive the ink from the ink receiver 123 if the amount of the disposed ink is large. The absorber 245 is made of a continuous porous material (spongy material).
The cleaning operation will be described in detail according to the flowchart shown in FIG. 5. First, the plunger 143 is operated to press the blade 243 against the belt 211 in Step S81. Then, the conveyor belt 211 is moved so that the part thereof where the ink is adhered passes the blade 243, and most of the ink is swept by the blade 243 in Step S82. When the conveyor belt 211 is stopped after the sweep of the ink is completed, the plunger 143 is turned off to separate the blade 243 from the belt 211 in Step S83.
Subsequently, in Step S84, the belt 211 is moved by the distance at which the belt 211 moves when the blade 243 and the absorber 245 abuts against the belt 211.
This movement aims to subsequently clear the bellt 211 of residual ink drops, left by the track of the blade edge, by the absorber 245.
In Step S85, the absorber 245 is pressed against the belt 211 by the plunger 144 for an arbitrary time. After that, the plunger 144 is turned off in Step S86 so as to separate the absorber 245 from the belt 211. The cleaning sequence of the belt 211 is completed and the sequence at the time when the eject operation is completed is executed again.
The sequence shown in FIG. 6 may be suitable depending on the mechanism of the recording apparatus. If the driving force of conveyor belt 211 does not have any margin when the blade 243 is pressed against conveyor belt 211, the performance of the blade 243 of sweeping out the ink on conveyor belt 211 may be lowered. In this case, the absorber 245 is pressed against conveyor belt 211 simultaneously with the press of the blade 243, thereby complementing the cleaning operation.
First, in step S101, the blade 243 and the absorber 245 are pressed against conveyor belt 211. In Step S102, conveyor belt 211 to which the ink is adhered is moved by a predetermined amount whereby the ink is swept from conveyor belt 211 by the blade 243 and the absorber 245. Subsequently, in Step S103 only the blade 243 is separated from conveyor belt 211, and in Step S104 conveyor belt 211 is moved by the distance at which conveyor belt 211 moves when the blade 243 and the absorber 245 abut against conveyor belt 211. In Step S105, conveyor belt 211 is stopped in this state for an arbitrary time, the absorber 245 is separated from the belt 211. The cleaning sequence of conveyor belt 211 is completed at this point.
Although a fixed sequence is executed regardless of the amount of jetted ink in the above description, a cleaning time is set corresponding to the maximum ink jet amount in this case. If the ink jet amount is extremely small, it is likely that the blade 243 will be turned up and chatter will be caused.
Furthermore, another embodiment will be described. In the embodiment, the sequence is changed depending upon the actual ink jet amount. FIG. 7 is a flowchart of the embodiment and FIG. 8 is a block diagram thereof. The block diagram shown in FIG. 8 is also applied to the abovementioned embodiments.
When the cleaning operation is started, a counter l is set at 0 (Step S80). Then, Steps S81 to S86 shown in FIG. 5 are executed except that a predetermined rotation amount n in Step S82 and a contact time m of the absorber 245 in Step S85 are variable. The value of the counter l is then increased by one (Step S87) and compared with a constant k described below (Step S88). If l is smaller than the constant k, Step S81 is executed again and the cleaning operation is repeated. If l is larger than or equal to the constant k, the cleaning operation is ended.
The above values of the blade cleaning time n, the absorber contact time m and the constant k are determined depending upon the amount of the ink which is actually jetted onto conveyor belt 211. The determination will be described with reference to FIG. 8.
Referring to FIG. 8, an image signal is transmitted from a control unit 500 to the recording head 221 through a counter memory 901. The counter memory 901 always stores the amount of recording signals for a constant period. When the sensor 224 detects a jam, the amount of recording signals for a time (l/V), which is obtained by dividing the distance l between the first head (BK) to the sensor 224 by the process speed V, is compared with the value preset in a look-up table 902, and the values of the blade cleaning time n, the absorber contact time m and the constant k shown in FIG. 7 are determined (an example of the table in this embodiment is shown in FIG. 9). In other words, the operation time of the conveyor belt drive motor 102M and the plungers 143 and 144 are controlled through the control unit 500 according to the amount of ink. The control unit 500 controls the whole apparatus, and comprises a CPU, such as a microprocessor, a ROM storing the control program of the CPU shown in the flowcharts and various kinds of data, a RAM used as a working area of the CPU and temporarily holding various kinds of data, and so on.
Referring to FIG. 8, a supply roller drive motor 412M drives the supply roller 202A, a feeding roller drive motor 413M drives the feeding rollers 202B and a resist roller drive motor 415M drives the resist rollers 204. These motors 412M, 413M and 415M are controlled by the control unit 500. When a reset button 501 is turned on after the operator finishes jam processing, the sequence mode for cleaning the conveyor belt 211 is started. The control unit 500 also judges that a jam occurs if the sensor 224 does not detect the recording sheet within a first predetermined time after the resist roller 204 starts to rotate, or if the detection of the recording sheet by the sensor 224 is not completed within a second predetermined time.
According to the above embodiments, since the jam in the recording region is easily detected by a detection means, the surface of the conveyor belt is cleaned by a cleaning means disposed downstream of the recording region. Therefore, even if a jam or the like occurs and the ink is jetted onto a part of the recording region by the recording head and the surface of the conveyor belt is soiled, the ink is immediately swept away, it is possible to prevent the charging roller from being soiled and the ink from adhering to the rear of the next sheet of recording material.
If an ink jet recording method is used for recording, the present invention is quite effective for a recording head and a recording apparatus for use in, especially, an ink jet recording method which has a means for generating heat energy as energy used to jet ink (for example, an electro-thermal converter and a laser beam) and changes the state of the ink by the heat energy. This is because it is possible to achieve a high-density and high-precision recording according to such a method.
It is desirable that a typical construction or principle of the method is described based on the basic principle disclosed in, for example, U.S. Pat. Nos. 4,723,129 and 4,740,796. This method is applicable to both, what is called, on-demand and continuous ink jet printing. For example, in the case of the on-demand ink jet printing, this method is effective since heat energy is generated in an electro-thermal converter, disposed corresponding to a sheet or a liquid path where recording liquid (ink) is retained, by applying at least one drive signal corresponding to recording information and for rapidly increasing the temperature of the recording liquid over the temperature of nucleate boiling, and film boiling is caused in the recording liquid near the thermal action surface of the recording head, and as a result, one air bubble corresponding to one drive signal can be formed in the recording liquid. The recording liquid is jetted into air through the jet opening by an action force produced in the growth and contraction processes of the bubble so as to form at least one drop. If the drive signal is shaped in a pulse, since the growth and contraction of the bubble is immediately and properly executed, it is possible to achieve recording liquid jetting having an excellent responsibility. A suitable drive signal is disclosed in U.S. Pat. Nos. 4,463,359 and 4,345,262. The use of conditions described in U.S. Pat. No. 4,313,124 concerning the temperature rise rate of the above thermal action surface can achieve a more excellent recording.
The present invention includes the construction of a recording head disclosed in the above patents, that is, the construction in combination of a jet opening, a liquid path and an electro-thermal converter (linear liquid passage or rectangular liquid passage), and in addition, the construction, in which the thermal action portion is bent, disclosed in U.S. Pat. Nos. 4,558,333 and 4,459,600.
Furthermore, as described above, the present invention is effectively applicable to a full-line recording head having the length corresponding to the maximum width of a recording material which is recordable by a recording apparatus. Such a recording head may be constituted by the combination of a plurality of recording heads to have the above length or by an integral recording head.
In addition, the present invention is also effective to an exchangeable chip-type recording head in which an electrical connection to the body of the apparatus and the ink supply from the body of the apparatus are made possible by the attachment thereof to the body of the apparatus, or a cartridge type recording head unitarily mounted with an ink tank.
The addition of the recovery means for the recording head, preliminary auxiliary means and so on is preferable since the advantages of the present invention are further stabled thereby. Specifically, the addition of a capping means for the recording head, a cleaning means, a pressure or suction means, a preliminary heating means composed of an electro-thermal converter, another heating element, or the combination of the electro-thermal converter and the heating element, or the execution of a preliminary jetting mode for performing preliminary jetting operation apart from the recording operation, is effective in achieving a stable recording.
As for the kind and number of recording heads to be mounted, for example, one recording head may be mounted corresponding to a monotone ink, or a plurality of recording heads may be mounted corresponding to a plurality of inks different in color or density. In other words, for example, although the recording mode is not limited to a recording mode using a main single color, such as black, and a recording head may be composed of either an integral head or the combination of a plurality of heads, the present invention is extremely effective for an apparatus using a plurality of different colors or full colors by mixture.
Additionally, although the ink is a liquid in the above embodiments of the present invention, the ink may be, for example, a solid which is softened or liquidized when a recording signal is applied.
In addition, the ink jet recording apparatus of the present invention may be used as an image output terminal of an information processing apparatus, such as a computer, a copying apparatus in combination with a reader or the like, a facsimile apparatus having a transmit and receiving function, or the like.
As described above, according to the present invention, it is possible to provide a conveyor means which can restrain unnecessary ink from being jetted when a recording material is jammed, and a recording apparatus having such a conveyor means. It should also be understood that the present invention is not limited to the conveying means of the type depicted in the embodiments, but also includes transport devices generally as well.
While the present invention has been described with respect to what is presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. The present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A cleaning method for removing a recording ink from a surface of a recording material conveying belt of a recording apparatus. The method includes the steps of detecting a recording material jam; press contacting a cleaning member to a surface of the recording material conveying belt in response to the detected jam, thus removing from the belt surface an improper discharge of recording ink; and separating the cleaning member from the surface of the conveying belt after cleaning for a period of time. The period of time is determined based upon an amount of the recording ink discharged onto the conveying belt surface. | 1 |
This application is a continuation of U.S. patent application Ser. No. 13/048,445, filed Mar. 15, 2011, now U.S. Pat. No. 8,474,476, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/313,902, filed Mar. 15, 2010, and U.S. Provisional Patent Application Ser. No. 61/313,918, filed Mar. 15, 2010, the entire disclosures of which are incorporated by reference herein.
This application is also related to U.S. Pat. No. 8,042,565, U.S. Pat. No. 7,472,718, and U.S. Pat. No. 7,730,901, the entire disclosures of which are incorporated by reference herein.
FIELD OF THE INVENTION
Embodiments of the present invention are generally related to contamination proof hydrants that employ a venturi that facilitates transfer of fluid from a self-contained water storage reservoir.
BACKGROUND OF THE INVENTION
Hydrants typically comprise a head interconnected to a water source by way of a vertically oriented standpipe that is buried in the ground or interconnected to a fixed structure, such as a roof. To be considered “freeze proof” hydrant water previously flowing through the standpipe must be directed away from the hydrant after shut off. Thus many ground hydrants 2 currently in use allow water to escape from the standpipe 6 from a drain port 10 located below the “frost line” 14 as shown in FIG. 1 .
Hydrants are commonly used to supply water to livestock that will urinate and defecate in areas adjacent to the hydrant. It follows that the animal waste will leach into the ground. Thus a concern with freeze proof hydrants is that they may allow contaminated ground water to penetrate the hydrant through the drain port when the hydrant is shut off. More specifically, if a vacuum, i.e., negative pressure, is present in the water supply, contaminated ground water could be drawn into the standpipe and the associated water supply line. Contaminants could also enter the system if pressure of the ground water increases. To address the potential contamination issue, “sanitary” yard hydrants have been developed that employ a reservoir that receives water from the standpipe after hydrant shut off.
There is a balance between providing a freeze proof hydrant and a sanitary hydrant that is often difficult to address. More specifically, the water stored in the reservoir of a sanitary hydrant could freeze which can result in hydrant damage or malfunction. To address this issue, attempts have been made to ensure that the reservoir is positioned below the frost line or located in an area that is not susceptible to freezing. These measures do not address the freezing issue when water is not completely evacuated from the standpipe. That is, if the reservoir is not adequately evacuated when the hydrant is turned on, the water remaining in the reservoir will effectively prevent standpipe water evacuation when the hydrant is shut off, which will leave water above the frost line.
To help ensure that all water is evacuated from the reservoir, some hydrants employ a venturi system. A venturi comprises a nozzle and a decreased diameter throat. When fluid flows through the venturi a pressure drop occurs at the throat that is used to suction water from the reservoir. That is, the venturi is used to create an area of low pressure in the fluid inlet line of the hydrant that pulls the fluid from the reservoir when fluid flow is initiated. Sanitary hydrants that employ venturis must comply with AS SE-1057, ASSE-0100, and ASSE-0152 that require that a vacuum breaker or a backflow preventer be associated with the hydrant outlet to counteract negative pressure in the hydrant that may occur when the water supply pressure drops from time-to-time which could draw potentially contaminated fluid into the hydrant after shut off. Internal flow obstructions associated with the vacuum breakers and backflow preventers will create a back pressure that will affect fluid flow through the hydrant. More specifically, common vacuum breakers and backflow preventers employ at least one spring-biased check valve. When the hydrant is turned on spring forces are counteracted and the valve is opened by the pressure of the fluid supply, which negatively influences fluid flow through the hydrant. In addition an elongated standpipe will affect fluid flow. These sources of back pressure influence flow through the venturi to such a degree that a pressure drop sufficient to remove the stored water from the reservoir will not be created. Thus to provide fluid flow at a velocity required for proper functioning of the venturi, fluid diverters or selectively detachable backflow preventers, i.e., those having a quick disconnect capability, have been used to avoid the back pressure associated with the vacuum breakers of backflow preventers. In operation, as shown in FIG. 2 , the diverter is used initially for about 45 seconds to ensure reservoir evacuation. Then, the diverter is disengaged so that the water will flow through the backflow preventer or vacuum breaker. The obvious drawback of this solution is that the diverter must be manually actuated and the user must allow water to flow for a given amount of time, which is wasteful.
Further, as the standpipe gets longer it will create more backpressure, i.e., head pressure, that reduces the flow of water through the venturi, and at some point a venturi of any design will be unable to evacuate the water in the reservoir. That is, the amount of time it takes for a hydrant to evacuate the water into the reservoir depends on the height/length of the standpipe as well as the water pressure. The evacuation time of roof hydrants of embodiments of the present invention, which has a 42″ standpipe, is 5 seconds at 60 psi. The evacuation time will increase with a lower supply pressure or increased standpipe length or diameter. Currently existing hydrants have evacuation times in the 30 second range.
Another way to address the fluid flow problem caused by vacuum breakers is to provide a reservoir with a “pressure system” that is capable of holding a pressure vacuum that is used to suction water from the standpipe after hydrant shut off. During normal use the venturi will evacuate at least a portion of the fluid from the reservoir. Supply water is also allowed to enter the reservoir which will pressurize any air in the reservoir that entered the reservoir when the reservoir was at least partially evacuated. When flow through the hydrant is stopped, the supply pressure is cut off and the air in the reservoir expands to created a pressure drop that suctions water from the standpipe into the reservoir. If the vacuum produced is insufficient, which would be attributed to incomplete evacuation of the reservoir, water from the standpipe will not drain into the reservoir and water will be left above the frost line.
Other hydrants employ a series of check valves to prevent water from entering the reservoir during normal operations. Hydrants that employ a “check system” uses a check valve to allow water into or out of the reservoir. When the hydrant is turned on, the check valve opens to allow the water to be suctioned from the reservoir. The check also prevents supply water from flowing into the reservoir during normal operations, which occurs during the operation of the pressure vacuum system. When the hydrant is shut off, the check valve opens to allow the standpipe water to drain into the reservoir. One disadvantage of a check system is that it requires a large diameter reservoir to accommodate the check valve. Thus a roof hydrant would require a larger roof penetration and a larger hydrant mounting system, which may not be desirable.
Another issue associated with both the pressure vacuum and check systems is that there must be a passageway or vent that allows air into the reservoir so that when a hydrant is turned on, the water stored in the reservoir can be evacuated. If the reservoir was not exposed to atmosphere, the venturi would not create sufficient suction to overcome the vacuum that is created in the reservoir.
SUMMARY OF THE INVENTION
It is one aspect of embodiments of the present invention to provide a sanitary and freeze proof hydrant that employs a venturi for suctioning fluid from a fluid storage reservoir. As one of skill in the art will appreciate, the amount of suction produced by the venturi is a function of geometry. More specifically, the contemplated venturi is comprised of a nozzle with an associated throat. Water traveling through the nozzle creates an area of low pressure at or near the throat that is in fluid communication with the reservoir. In one embodiment, the configuration of the nozzle and throat differs from existing products. That is, the contemplated nozzle is configured such that the venturi will operate in conjunction with a vacuum breaker, a double check backflow preventer, or a double check backflow prevention device as disclosed in U.S. Patent Application Publication No. 2009/0288722, which is incorporated by reference in its entirety herein, without the need for a diverter. Preferably, embodiments of the present invention are used in conjunction with the double check backflow prevention device of the '722 publication as it is less disruptive to fluid flow than the backflow preventers and vacuum breakers of the prior art.
While the use of a venturi is not new to the sanitary yard hydrant industry, the design features of the venturi employed by embodiments of the present invention are unique in the way freeze protection is provided. More specifically, current hydrants employ a system that allows water to bypass a required vacuum breaker. For example, the Hoeptner Freeze Flow Hydrant employs a detachable vacuum breaker and the Woodford Model S3 employs a diverter. Again, fluid diversion is needed so that sufficient fluid flow is achieved for proper venturi functions. The venturi design of sanitary hydrants of the present invention is unique in that the venturi will function properly when water flows through the vacuum breaker or double check backflow preventer—no fluid diversion at the hydrant head is required. This allows the hydrant to work in a way that is far more user friendly, because the hydrant is able to maintain its freeze resistant functionality without requiring the user to open a diverter, for example. Embodiments of the present invention are also environmentally friendly as resources are conserved by avoiding flowing water out of a diverter.
It is another aspect of the embodiments of the invention is to provide a hydrant that operates at pressures from about 20 psi to 125 psi and achieves a mass flow rate above 3 gallons per minute (GPM) at 25 psi, which is required by code. One difficult part of optimizing the flow characteristics to achieve these results is determining the nozzle diameter. It was found that a throat diameter change of about 0.040 inches would increase the mass flow rate by 2 GPM. That same change, however, affects the operation of the venturi. For example, hydrants with a nozzle diameter of 0.125 inches will provide acceptable reservoir evacuation but would not have the desired mass flow rate. A 0.147 inch diameter nozzle will provide an acceptable mass flow rate, but reservoir evacuation time was sacrificed. In one embodiment of the present invention a venturi having a nozzle diameter of about 0.160 inches is employed.
It is another aspect of the present invention to provide a nozzle having an exit angle that facilitates fluid flow through the venturi. More specifically, the nozzle exit of one embodiment possesses a gradual angle so that fluid flowing through the venturi maintains fluid contact with the surface of the nozzle and laminar flow is generally achieved. In one embodiment the exit angle is between about 4 to about 5.6 degrees. For example, nozzle exit having very gradual surface angle, e.g. 1-2 degrees, will evacuate the reservoir more quickly, but would require an elongated venturi. Thus, an elongated venturi may be used to reduce back pressure associated with the venturi, but doing so will add cost. The nozzle inlet may have an angle that is distinct from that of the exit to facilitate construction of the venturi by improving the machining process.
It is thus one aspect of the present invention to provide a sanitary hydrant, comprising: a standpipe having a first end and a second end; a head for delivering fluid interconnected to said first end of said standpipe; a fluid reservoir associated with said second end of said standpipe; a venturi positioned within said reservoir and interconnected to said second end of said standpipe, said venturi comprised of a first end, which is interconnected to said standpipe, and a second end associated with a fluid inlet valve with a throat between said first end and said second end of said venturi; a bypass tube having a first end interconnected to a location adjacent to said first end of said venturi and a second end interconnected to a bypass valve, said bypass valve also associated with said second end of said venturi, wherein when said bypass valve is opened, fluid flows from said inlet valve, through said bypass tube, through said standpipe, and out said hydrant head; and wherein when said bypass valve is closed, fluid flows through said venturi, thereby creating a pressure drop adjacent to said throat that communicates with said reservoir to draw fluid therefrom.
It is another aspect to provide a method of evacuating a sanitary hydrant, comprising: providing a standpipe having a first end and a second end; providing a head for delivering fluid interconnected to said first end of said standpipe; providing a fluid reservoir associated with said second end of said standpipe; providing a venturi positioned within said reservoir and interconnected to said second end of said standpipe, said venturi comprised of a first end, which is interconnected to said standpipe, and a second end associated with a fluid inlet valve with a throat between said first end and said second end of said venturi; providing a bypass tube having a first end interconnected to a location adjacent to said first end of said venturi and a second end interconnected to a bypass valve, said bypass valve also associated with said second end of said venturi, wherein when said bypass valve is opened, fluid flows from said inlet valve, through said bypass tube, through said standpipe, and out said hydrant head; and wherein when said bypass valve is closed, fluid flows through said venturi, thereby creating a pressure drop adjacent to said throat that communicates with said reservoir to draw fluid therefrom initiating fluid flow through said head by actuating a handle associated therewith; actuating a bypass button that opens the bypass valve such that fluid is precluded from entering said venturi; actuating said bypass button to close said bypass valve; flowing fluid through said venturi; evacuating said reservoir; ceasing fluid flow through said hydrant; and draining fluid into said reservoir.
The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detail Description, particularly when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions.
FIGS. 1A-1C are a depiction of the operation of a hydrant of the prior art;
FIGS. 2A-2C are a series of figures depicting the use of a flow diverter of the prior art;
FIG. 3 is a cross section of a venturi of the prior art;
FIG. 4 is a perspective view of a venturi system employed by the prior art;
FIG. 5 is a perspective view of one embodiment of the present invention;
FIG. 6 is a detailed view of the venturi system of the embodiment of FIG. 5 ;
FIG. 7 is a perspective view similar to that of FIG. 6 wherein the reservoir has been omitted for clarity;
FIG. 8 is a cross sectional view of a venturi system that employs a bypass tube of one embodiment of the present invention;
FIG. 9 is a cross sectional view of a bypass valve used in conjunction with the embodiment of FIG. 5 shown in an open position;
FIG. 10 shows the bypass valve of FIG. 9 in a closed position;
FIG. 11 is a top perspective view of one embodiment of the present invention showing a bypass button and an electronic reservoir evacuation button;
FIG. 12 is a graph showing sanitary hydrant comparisons;
FIG. 13 is a perspective view of a venturi system of another embodiment of the present invention;
FIG. 14 is a detailed cross sectional view of FIG. 13 showing the check valve in a closed position when the hydrant is on;
FIG. 15 is a detailed cross sectional view of FIG. 13 showing the check valve in an open position when the hydrant is off;
FIG. 16 is a cross sectional view showing a hydrant of another embodiment of the present invention;
FIG. 17 is a detail view of FIG. 16 ;
FIG. 18 is a detail view of FIG. 17
FIG. 19 is a cross section of another embodiment of the present invention; and
FIG. 20 is a table showing a comparison of various hydrant assemblies and the operation cycle of each.
It should be understood that the drawings are not necessarily to scale, but that relative dimensions nevertheless can be determined thereby. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
To assist in the understanding of one embodiment of the present invention the following list of components and associated numbering found in the drawings is provided herein:
#
Component
2
Hydrant
4
Head
5
Handle
6
Standpipe
10
Drain port
14
Frost line
18
Venturi
22
Diverter
26
Vacuum breaker
30
Siphon tube
34
Check valve
36
Outlet
37
Venturi vacuum inlet and drain port
38
Hydrant inlet valve
42
Bypass
46
Bypass button
50
Casing cover
54
Piston
56
Bypass valve
57
Control rod
58
Secondary spring operated piston
59
Bottom surface
60
EFR button
64
LED
68
Screen piston
72
Reservoir
76
Check valve piston
80
Vent
82
Inlet Check Valve
84
Outlet Check Valve
86
Fixed Inlet Volume
88
Fixed Outlet Volume
90
Valve Body
92
Inlet Check Body
94
Inlet Check Spring
96
Valve Cap
DETAILED DESCRIPTION
The venturi 18 and related components used in the hydrants of the prior art is shown in FIGS. 3 and 4 and functions when the hydrant issued in conjunction with a vacuum breaker and a diverter. The diverter is needed to allow the venturi to work properly in light of the flow obstructions associated with the vacuum breaker. A typical on/off cycle for this hydrant (see also FIG. 2 ) requires that the user open the hydrant to cause water to exit the diverter 22 and not the vacuum breaker 26 . As the water flows out of the diverter 22 , a vacuum is created that draws water through a siphon tube 30 and check valve 34 , which evacuates the reservoir (not shown). Flowing water through the diverter 22 for about 30 to 45 seconds will generally evacuate the reservoir. Next, as shown in FIG. 2 , the diverter 22 is pulled down to redirect the water out of the vacuum breaker 26 . The vacuum breaker 26 allows the hydrant 2 to be used with an attached hose and/or a spray nozzle as the vacuum breaker 26 will evacuate the head when the hydrant 2 is shut off, thereby making it frost proof. When the water is flowing out of the vacuum breaker 26 the venturi 18 will stop working and the one-way check valve 34 will prevent water from entering the reservoir. Once the hydrant is shut off, the water in the standpipe 6 will drain through a venturi vacuum inlet and drain port 37 that is in fluid communication with the reservoir similar to that disclosed in U.S. Pat. No. 5,246,028 to Vandepas, which is incorporated by reference herein. The check valve 34 is also pressurized when the hydrant is turned off because the shut off valve 38 is located above the check valve 34 .
A venturi assembly used in other hydrants that employ a pressurized reservoir also provides a vacuum only when water flows through a diverter. A typical on/off cycle for a hydrant that uses this venturi configuration is similar to that described above, the exception being that a check valve that prevents water from entering the reservoir is not used. When the diverter is transitioned so water flows through the vacuum breaker, the backpressure created thereby will cause water to fill and pressurize the reservoir, which prevents water ingress after hydrant shut off. As the reservoir is at least partially filled with water during normal use, the user needs to evacuate the hydrant after shut off by removing any interconnected hose and diverting fluid for about 30 seconds, which will allow the venturi to evacuate the water from the reservoir.
A hydrant of embodiments of the present invention shown in FIGS. 5-11 which may employ a venturi with an about ⅛″ diameter nozzle. To account for the decrease in mass flow and associated back pressure that affects the functionality of the venturi described above, a bypass 42 is employed. More specifically, the bypass 42 maintains the flow rate out of the hydrant head 4 and allows for water to be expelled from the head 4 at the expected velocity. Fluid bypass is triggered by actuating a button 46 located on the casing cover 50 as shown in FIG. 11 . When the hydrant is turned on the user pushes the bypass button 46 that will in turn move a bypass piston 54 of a bypass valve 56 into the open position as shown in FIG. 9 . This will allow water to bypass the venturi 2 and re-enter the standpipe above the restriction caused by the venturi. The increased flow rate is greater than could be achieved with a venturi alone, even if the diameter of the venturi nozzle was increased.
While the bypass allows the mass flow rate to increase greatly, it also causes the venturi to stop creating a vacuum that is needed to evacuate the reservoir. Before normal use, the bypass piston 54 is closed as shown in FIG. 10 . Similar to the system described in FIG. 16 below, the venturi 18 and associated bypass 42 are associated with a control rod 57 that is associated with the hydrant handle 5 . Opening of the hydrant transitions the control rod 57 upwardly, which pulls the venturi 18 and associated bypass 42 upwardly and opens the hydrant inlet valve 38 to initiate fluid flow. Conversely, transitioning the hydrant handle 5 to a closed position will move the venturi 18 and associated bypass 42 downwardly such that a secondary spring operated piston 58 of the bypass valve 56 well contact a bottom surface 59 of the reservoir. As the secondary spring piston 58 contacts the bottom surface 59 , the bypass valve 54 moves to a closed position as shown in FIG. 10 . Moving the handle 5 to an open position to initiate fluid flow through the hydrant head will separate the secondary spring operated piston 58 from the bottom surface 59 of the reservoir which allows the bypass piston 54 to move to an open position as shown in FIG. 9 when the bypass button 46 is actuated. When the bypass 42 is in the closed position, water is forced to flow through the venturi causing a vacuum to occur, thereby causing the reservoir to be evacuated each time the hydrant is used. After water flows from the vacuum breaker for a predetermined time, the user will actuate the bypass button 46 which opens the bypass valve 56 to divert fluid around the venturi 2 . The secondary spring operated piston 58 , which is designed to account for tolerances making assembly of the hydrant easier. The secondary spring operated piston 58 also makes sure the hydrant will operate properly if there are any rocks or debris present in the hydrant reservoir.
The venturi 18 of this embodiment can be operated in a 7′ bury hydrant with a minimum operating pressure of 25 psi. The other major exception is the addition of the aforementioned bypass valve 56 that allows the hydrant to achieve higher flow rates.
In operation with a hose, initially the hose is attached to the backflow preventer 26 or the bypass button is pushed to that the venturi will not operate correctly and the one way check valve 34 will be pressurized in such a way to prevent flow of fluid from the reservoir. After the hydrant is shut off, the hose is removed from vacuum breaker 26 . Next the hydrant 2 is turned on and water flows through the vacuum breaker 26 for about 30 seconds. When there is no hose attached, and the bypass has not been activated, the venturi 18 will create a vacuum that suctions water from the reservoir 72 and making the hydrant frost proof. Thus when the hydrant is later shut off, the check valve piston will move up and force open the one way check valve 34 to allow water in the hydrant to drain into the reservoir. This operation will also reset the bypass valve 56 into the closed position.
Some embodiments of the present invention will also be equipped with an Electronic Freeze Recognition (EFR) device as shown in FIG. 11 . The EFR includes a button 60 that allows the user to ascertain if the water has been evacuated from the standpipe 6 properly and if the hydrant is ready for freezing weather. The device uses a circuit board in concert with a dual color LED 64 as shown in FIG. 11 to warn the operator of a potential freezing problem. When the EFR button 60 is pushed and the LED 64 glows red it indicates that the hydrant has not been evacuated properly. This informs the operator that the water in the reservoir is above the frost line, and the hydrant needs to be evacuated by the method described above. A green LED 64 indicates the hydrant has been operated properly and the hydrant is ready for freezing weather.
Flow rates for hydrants of embodiments of the present invention compare favorably with existing sanitary hydrants on the market, see FIG. 12 . The prior art models are compared with hydrants that use a vacuum breaker and hydrants that use a double check backflow preventer. The venturi and related bypass system will meet ASSE 1057 specifications.
Another embodiment of the present invention is shown in FIGS. 13-15 that does not employ a bypass. Variations of this embodiment employ an about 0.147 to an about 0.160 diameter nozzle, which allows for a flow rate of 3 gallons per minute at 25 psi and evacuation of the reservoir at 20 psi. As this configuration meets the desired mass flow characteristics, a bypass is not required to obtain the mass flow rate, and therefore this hydrant can be produced at a lower cost. This embodiment also employs a dual-use check valve. The check valve is closed by a spring when the hydrant is turned on as shown in FIG. 14 to prevent water from filling the reservoir. Again, when water is flowing through the double check backflow preventer a suction can still be produced to pull water from the reservoir through this check valve. When the hydrant is turned off, a screen piston 68 moves up when it contacts the bottom surface 59 of the reservoir which forces the check valve 34 into the open position as shown in FIG. 15 . This allows the water in the hydrant to drain into the reservoir, thereby making the hydrant freeze resistant. Other embodiments of the present invention employ a venturi to evacuate a reservoir, but do not need a diverter to operate correctly. More specifically, a venturi is provided that will evacuate a reservoir through a double check backflow preventer.
The check valve 34 depicted in FIGS. 14 and 15 is a double check valve 34 comprising an inlet check valve 82 and an outlet check valve 84 . A fixed inlet volume 86 and a fixed outlet volume 88 are at least partially defined within a valve body 90 of the double check valve 34 . A valve cap 96 at least partially defines the fixed inlet volume 86 and secures the components of the inlet check valve 82 , and the fixed inlet volume 86 provides space components of the inlet check valve 82 . Similarly, the fixed outlet volume 88 provides space for components of the outlet check valve 84 .
In the embodiment depicted in FIGS. 14 and 15 , the inlet check valve 82 comprises an inlet check body 92 and an inlet check spring 94 . Other embodiments may optionally include an inlet check seal that is disposed about the inlet check body 92 . The inlet check body 92 is disposed in the inlet check spring 94 such that the inlet check body 92 is biased downward. When the inlet check body 92 is fully biased downward, the inlet check body prevents fluid flow from the inlet check valve 82 into the outlet check valve 84 , but allows fluid flow from the outlet check valve 84 into the inlet check valve 82 .
The outlet check valve 84 depicted in FIGS. 14 and 15 comprises a screen piston 68 . The screen portion of the screen piston 68 filters any rocks or debris from the reservoir 72 . FIG. 15 depicts the double check valve 34 in the closed position where the screen of the screen piston 68 contacts a bottom surface 59 of the reservoir 72 . This drives the screen piston 68 upward into the inlet check body 92 such that a seal between the inlet check body 92 and the valve body 90 is broken and fluid may drain into the reservoir 72 .
FIGS. 16-18 show a hydrant of another embodiment of the present invention that is simpler and more user friendly than sanitary hydrants currently in use. This hydrant is limited to a 5′ bury depth and a minimum working pressure of about 40 psi, which maximizes the venturi flow rate potential, while still being able to evacuate the reservoir as water flows through a double check. A one-way check valve 34 is provided that is forced open when the hydrant is shut off as shown in FIG. 17 .
In operation, this venturi system operates similar to those described above with respect to FIGS. 5-11 . More specifically, the venturi is interconnected to a movable control rod 57 that is located within the standpipe 6 . The handle 5 of the hydrant is thus ultimately interconnected to the venturi 18 and by way of the control rod 57 . To turn on the hydrant, the user moves the handle 5 to an open position, which pulls the control rod 57 upwardly and opens the inlet valve 38 such that water can enter the venturi 18 . Pulling the venturi upward also removes the check valve 34 upwardly such that the screen piston 68 moves away from the bottom surface 59 of the hydrant 2 . To turn the hydrant off, the handle 5 is moved to a closed position which moves the control rod 57 downwardly to move the venturi 18 downwardly to close the inlet valve 38 . Moving the venturi downwardly also transitions the screen piston 68 which opens the check valve 34 . To allow for evacuation reservoir a vent 80 may be provided on an upper surface of the hydrant.
Generally, this hydrant functions when a hose is attached to the backflow preventer. When the hose is attached, the venturi will not operate correctly and the pressure acting on the one way check valve 34 will prevent water ingress into the reservoir 72 . After the hydrant is shut off, the hose is removed from vacuum breaker, the hydrant must be turned on so that the water can flow through the double check vacuum preventer for about 15 seconds. That is, when there is no hose attached, the venturi will create a vacuum sufficient enough to suction water from the reservoir 72 , and making the hydrant frost proof. When the hydrant is later shut off, the check valve piston 26 will move up and force the one way check valve to an open position which allows the water in the hydrant to drain into the reservoir 72 .
FIG. 19 shows yet another hydrant of embodiments of the present invention that is designed specifically for mild climate use (under 2′ bury) and roof hydrants. The outer pipe of the roof hydrant is a smaller 1½ diameter PVC, instead of the 3″ used in some of the embodiments described above. This hydrant uses a venturi without a check valve in concert with a pressurized reservoir, a diverter is not used. The operation is the same as described above with respect to hydrant with a pressurized reservoir, with the evacuation of the reservoir being completed after the user detaches the hose.
FIG. 20 is a table comparing the embodiments of the present invention, which employ an improved venturi of that employ a bypass system, with hydrants of the prior art manufactured by the Assignee of the instant application. The embodiment shown in FIG. 7 , for example, provides an increased flow rate, has an increased bury depth, and can operate at lower fluid inlet pressures. The evacuation time is discussed over the prior art.
While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. For example, aspects of inventions disclosed in U.S. Pat. Nos. and Published Patent Application Nos. 5,632,303, 5,590,679, 7,100,637, 5,813,428, and 20060196561, all of which are incorporated herein by this reference, which generally concern backflow prevention, may be incorporated into embodiments of the present invention. Aspects of inventions disclosed in U.S. Pat. Nos. 5,701,925 and 5,246,028, all of which are incorporated herein by this reference, which generally concern sanitary hydrants, may be incorporated into embodiments of the present invention. Aspects of inventions disclosed in U.S. Pat. Nos. 6,532,986, 6,805,154, 6,135,359, 6,769,446, 6,830,063, RE39,235, 6,206,039, 6,883,534, 6,857,442 and 6,142,172, all of which are incorporated herein by this reference, which generally concern freeze-proof hydrants, may be incorporated into embodiments of the present invention. Aspects of inventions disclosed in U.S. Pat. Nos. and Published Patent Application Nos. D521,113, D470915, 7,234,732, 7,059,937, 6,679,473, 6,431,204, 7,111,875, D482,431, 6,631,623, 6,948,518, 6,948,509, 20070044840, 20070044838, 20070039649, 20060254647 and 20060108804, all of which are incorporated herein by this reference, which generally concern general hydrant technology, may be incorporated into embodiments of the present invention. | A freeze resistant sanitary hydrant is provided that employs a reservoir for storage of fluid under the frost line or in an area not prone to freezing. To evacuate this reservoir, a means for altering pressure is provided that is able to function in hydrant systems that employ a vacuum breaker. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to coating devices and in particular to devices for coating a paper web.
2. Description of Related Technology
The state of the art regarding paper coating devices is described in the following publications:
(1) DE-GM 8 414 413;
(2) U.S. Pat. No. 2,729,192;
(3) U.S. Pat. No. 2,946,307;
(4) U.S. Pat. No. 3,084,663;
(5) U.S. Pat. No. 5,112,653;
(6) EP Patent Application 93 112 695; and
(7) EP 507 218 A1 (corresponding to U.S. Pat. No. 5,230,165).
With reference to FIG. 1 of publication (7), a known coating device has two applicator rolls which form a gap through which a paper web passes. A nozzle applicator station is assigned to each of the two applicator rolls where a coating composition film is applied onto a surface of a respective roll. The nozzle applicator station has a nozzle with two nozzle lips, one of which has a roller blade on a free end thereof. Thus, a metered application of a coating composition onto the surface of a particular roll is possible. Accordingly, such a device provides an indirect method of application of a coating onto paper because the coating is first applied onto a surface of the roll and is then transferred from the roll onto a paper web.
It is also possible to use applicator stations different from the one described in publication (7). Moreover, it may not be necessary to coat both sides of a paper web. Thus, for example, it may be possible to coat only one side of a paper web or to apply coating on both sides of a web but at different rates whereby several roll pairs are provided at an assigned applicator station and a paper web is dried each time it receives a coating.
Such coating devices have proven sufficient in the past. However, a problem with such devices that has not been satisfactorily addressed is known as the orange-peel effect wherein the coating is not flat on the paper web after the paper leaves the roll gap but rather has a surface that is reminiscent of the appearance of an orange peel. Many attempts have been made to eliminate the orange-peel effect, as, for example, by utilizing a smoothing or rubbing element connected to the coating device. Although such a measure makes it possible to ameliorate the undesirable orange-peel effect, it typically has not completely eliminated it. In addition, providing rubbing elements, for example, results in increased equipment cost.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome one or more of the problems described above. It is also an object of the invention to provide a coating device that reduces or eliminates the orange-peel effect without any significant additional equipment expenditure.
According to the invention, a device for coating a paper web includes two applicator rolls disposed parallel to one another, forming a roll gap for the passage of a paper web therethrough. At least one applicator for applying a coating onto a surface of at least one of the rolls is also provided. The coating roll thereafter transfers the coating onto one side of a paper web disposed in the roll gap. Guide elements disposed downstream of the roll gap with respect to a direction of travel of the paper web through the device include at least one beam-like air guide element adapted to create an air cushion between the paper web and a surface of the air guide element facing the paper web. The air guide element may be disposed in such a manner as to deflect a paper web at least once downstream of the roll gap. Also, at least one air guide element is disposed directly downstream of the roll gap at a distance therefrom of about 0.3 to about 1 times the diameter of at least one of the rolls.
Other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a device according to the invention.
FIG. 2 is a is a schematic view of a second embodiment of a device according to the invention.
FIG. 3 is an enlarged and partial schematic view of a third embodiment of a device according to the invention.
FIG. 4 is an enlarged and partial schematic view of a fourth embodiment of a device according to the invention.
FIG. 5 is a an enlarged and partial schematic view of a fifth embodiment of a device according to the invention.
FIG. 6 is an enlarged and partial schematic view of a sixth embodiment of a device according to the invention.
FIG. 7 is a schematic view of a seventh embodiment of a device according to the invention.
FIG. 8 is a schematic view of an eighth embodiment of a device according to the invention.
FIG. 9 is a schematic view of a ninth embodiment of a device according to the invention.
FIG. 10 is a schematic view of a tenth embodiment of a device according to the invention.
FIG. 11 is a schematic view of an eleventh embodiment of a device according to the invention.
FIG. 12 is a schematic view of a twelfth embodiment of a device according to the invention.
FIG. 12a is a schematic view of an infrared drying section of a device according to the invention.
FIG. 12b is a schematic view of a second embodiment of an infrared drying section of a device according to the invention.
FIG. 13 is a cross-sectional and partially schematic view of a thirteenth embodiment of a device according to the invention.
FIG. 14a is a partial perspective view of a beam-like air guide element according to the invention.
FIG. 14b is a partial perspective view of a second embodiment of a beam-like air guide element according to the invention.
FIG. 14c is a partial schematic view of a portion of a device according to the invention showing two beam-like air guide elements.
FIG. 14d is a partial perspective view of a third embodiment of a beam-like air guide element according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
In past attempts to reduce or eliminate the orange peel effect during paper coating, it has been discovered that the effect is influenced by numerous operational parameters. Thus, it is known that the orange peel effect is influenced by the type of coating composition utilized, for example, by its viscosity. The velocity of travel of a web through the device also plays a role. However, web velocity cannot be controlled because different paper qualities require different web velocities. The paper quality itself also plays a role in the orange peel effect, especially paper composition and surface characteristics. In addition, all parameters influence one another mutually so that it has previously been impossible to alleviate the orange peel problem in all cases.
Two parameters which previously have not been considered with regard to the orange peel effect problem appear to play a decisive role in the problem. One of these parameters is the angle of take-off, i.e., the angle at which the paper web leaves the roll gap after application of the coating. Another parameter is the web tension which exists in the paper web downstream of the roll gap with respect to the direction of travel of the web. Both of these parameters must be precisely adjusted. The second parameter presents some difficulties because the coated paper web, which is moist, cannot be allowed to run through a pair of tension rollers (i.e., a pair of driven rolls), which would hold the web under tension and thus transfer a certain tensile force onto the web. Thus, in light of the importance of the web take-off angle, a measure to apply a positive tensile force is utilized according to the invention which comprises disposing at least one air guide element directly downstream of the roll gap at a distance therefrom of about 0.3 to about 1 (preferably about 0.5 to about 0.8) times the diameter of one of the coating rolls. In this way, ideal coating conditions can be created.
Also according to the invention, directly downstream of at least one beam-like air guide element is a dryer portion that may include air floater-type (i.e., suspension) and infrared dryers. The air outlet velocity from the beam-like guide elements as well as into the air floater-type dryers can be accurately adjusted. Furthermore, the infrared dryer is particularly disposed in relation to the air floater-type dryers. Finally, both the air floater-type dryers and the infrared dryers each preferably have a certain length with respect to the direction of movement of a web through the device.
In the past it was not possible to place an infrared dryer directly downstream of the roll gap formed by two applicator rolls of a coating station. This is because the point of separation of the paper web from one of the rolls is typically not well-defined as it oscillates with respect to the direction of movement of a web through the device. However, placing an infrared dryer near the roll gap is possible according to the invention by utilizing an air guide element according to the invention directly downstream of the roll gap. Installation of an infrared dryer near the roll gap is especially preferred because the infrared radiation penetrates deeply into the paper web, has a high energy density, and heats the water contained in the paper web, so that in the downstream floater-type dryer section evaporation can be achieved relatively easily.
Various embodiments of devices according to the invention concern the placement of a first infrared dryer of the drying portion of the device disposed downstream of the roll gap. In some embodiments of the invention, the first infrared dryer is disposed immediately after at the beam-like air guide element (of which there is at least one). However, in some cases, it is desirable to dispose the infrared dryer at about the same slight distance from the roll gap as the beam-like air guide element. Thus, in such an embodiment of a device according to the invention, an infrared dryer is provided which itself can produce a carrier-air cushion between it and the coated paper web.
With reference to the drawings, FIG. 1 shows a coating installation device according to the invention having two coating stations with drying devices disposed therebetween. FIGS. 2 to 5 show coating stations to which guide elements are connected in various configurations.
FIG. 1 shows a first coating station, generally 1, which has two coating rolls. An applicator station 1.1 is assigned to one of the two rolls. A tensile device is disposed downstream of the coating station with reference to the direction of travel of a paper web 11 through the device. The tensile device includes two beam-like air guide elements 2 and 3. Downstream of the elements 2 and 3 is an infrared dryer section 4, a short drying portion, generally 5, having three drying cylinders 5.1, 5.2 and 5.3, a suction guide roll 5.4 and a number of guide rolls. A second coating station, generally 6, also has two rolls. An applicator station 6.1 is assigned to one of the rolls. Downstream of the coating station 6 is an infrared dryer section 7 and then a final dryer group, generally 8.
A device according to the invention shown in FIG. 2 includes a two-row cylinder dryer portion, generally 1a (only one end thereof is shown). Downstream of the dryer portion 1a, with respect to the direction of travel of a paper web 11 through the device are a calender 3a, a first coating station, generally 5a, followed by a dryer 6a and a dryer portion, generally 7a, having drying cylinders, a second coating station, generally 8a, another dryer 9, a dryer portion 9.1 with drying cylinders and a roll-up station, generally 10'.
Each of the two coating stations 5a and 8a have two nozzle applicator stations 5.1a, 5.2a and 8.1a and 8.2a, respectively. This means that the paper web 11 can be coated on both sides in each coating station. The dryers 6a and 9 are floater-type dryers which carry the web 11 in a free-floating manner and bring the web to such a dry content (at least 70% dry) that the coating on the paper can be touched in the downstream cylinder drying groups 7a and 9.1, respectively.
FIGS. 3-6 each show coating stations, air guide elements and drying devices according to the invention. The coating station shown in FIG. 3 includes two rolls 10 and 20 of substantially equal diameter D. A nozzle applicator station 10.1 is assigned to the roll 10. The other roll 20 does not have such an applicator station. A paper web 11 is guided through a roll gap formed by the rolls 10 and 20 in the direction of the arrow A. Downstream of the roll gap is a guide element in the form of a beam-like air guide element 12. The air guide element 12 (shown schematically) includes a hollow profile beam which has a plurality of bores 12.1 on a side of the beam that faces the paper web 11. The bores 12.1 extend over the entire length of the air guide element 12 and thus over the entire width of the paper web 11.
Downstream of the air guide element 12 with respect to the direction of travel of the paper web 11 is an infrared dryer section 13, followed by a floater-type dryer section, generally 14. The floater-type dryer section 14 also has air guide elements 14.1, 14.2, 14.3 similar to the air guide element 12. The air outlet velocity from the floater-type dryer section 14 is preferably between about 20 m/s and about 80 m/s.
The paper web 11 is guided through the device as follows: After the web passes through the vertex (roll gap) of the two rolls 10 and 20, the paper web 11 first loops around the roll 10 at a selected angle of wrap x (preferably between about 0° and about 5°). The web 11 then loops around the beam-like air guide element 12, where it undergoes another slight deflection. Further deflections of the paper web 11 occur within the floater-type dryer section 14 as the web 11 is conveyed through the air guides 14.1, 14.2, and 14.3.
Another infrared dryer section 15 is disposed downstream of the floater-type dryer section 14.
It is important that the first dryer disposed downstream of the beam-like air guide element 12 be an infrared dryer. In other words, if the guide element 12 is disregarded, the location of the infrared drying section 13 is immediately downstream the coating station rolls 10 and 20. Furthermore, it is preferred that the entire drying portion of the coating device according to the invention has more than two drying sections, particularly preferred is at least three drying sections, and that the infrared drying sections and the floater-type drying sections alternate.
FIG. 4 illustrates a portion of an embodiment of a device according to the invention also having two applicator rolls 10 and 20. In contrast to the embodiment according to FIG. 3, nozzle applicator stations 10.1 and 10.2 are assigned to rolls 10 and 20, respectively. Thus, a paper web 11 receives a coating on both sides. However, the nozzle 10.1 can be omitted, so that only one side of the paper web 11 receives a coating.
Downstream of the roll gap formed by the rolls 10 and 20 are two beam-like air guide elements 22 and 23 disposed on opposite sides of the paper web 11. Downstream of the air guide element 23 is an infrared drying section 24, a floater-type drying section 25 and an infrared drying section 26. The three drying sections 23, 24, and 25 are of equal lengths with respect to the direction of travel of the paper web 11 through the device.
With respect to FIG. 4, the paper web 11 leaving the roll gap loops around the roll 10 only very slightly. The angle of wrap x is so small that it cannot be seen in FIG. 4. The looping of the web 11 around the air guide elements 22 and 23 is also very slight (also cannot be seen in FIG. 4).
In an embodiment of a device according to the invention shown in FIG. 5, a roll gap is formed by the coating applicator rolls 10 and 20. Only the roll 10 has an applicator station 10.1 assigned thereto. A bank of three beam-like air guide elements 30, 31, 32 are disposed downstream of the roll gap with respect to the direction of travel of a paper web 11 shown by an arrow A. Downstream of the air guide element 32 is an infrared drying section 34, a floater-type drying section 35, another infrared drying section 36, and another floater-type drying section 37. The two floater-type drying sections are of the same length with respect to the direction of travel of the web 11 through the device. However, the floater-type drying section 37 is longer than floater-type drying section 35. The reason for this is that the paper web 11, and especially the water contained in the web, must be heated by an infrared drying section and only then enter a floater-type drying section. Because of the increasing dry content of the web, such heating requires more and more heat output, i.e., longer floater-type drying sections, in order to drive out residual water from the paper web. An infrared drying section preferably has a length of about 300 mm to about 700 mm and a floater-type drying section preferably has a length of about 50 mm to about 400 mm.
In an embodiment of a device according to the invention shown in FIG. 6, a paper web 11 is coated on both sides in a roll gap formed by the rolls 10 and 20 having applicator stations 10.1 and 20.1, respectively, assigned thereto. With respect to the direction A of a paper web 11 traveling through the device, downstream of the roll gap is a beam-like air guide element 40 disposed at one side of the web 11, followed by a bank of beam-like air guide elements 41 and 42 disposed on the opposite side of the paper web 11. An infrared section 42 and a floater-type drying section 43 are disposed downstream of the air guide elements 41 and 42.
With reference to the small distance E between the roll gap and the element 40, it can be seen that the element 40 ensures an unequivocally defined separation point between the web 11 and the roll 10. Thus, the separation point does not oscillate back and forth. If a coating composition is applied to only one side of the web 11, the roll 10 is utilized the applicator roll, and there is a relatively low angle of wrap x (see, e.g. FIG. 3), then the roll 10 can have a softer surface than the supporting roll 20. This is quite unusual because normally the web 11 follows and loops around the harder roll of a roll coating roll pair.
FIG. 7 shows another embodiment of a device according to the invention. Two applicator rolls 10 and 20 are disposed in such a way that a paper web 11 goes through the roll gap at an angle of about 20° to the vertical. Three beam-like air guide elements 50 are disposed downstream of the rolls 10 and 20 with respect to the direction of travel A of the web 11 through the device. Downstream of the elements 50 is a drying portion of the device, the elements of which are not shown in detail. The drying portion includes an infrared drying section 70 disposed directly downstream of the elements 50. Downstream of the drying section 70 is a floater-type drying section 72, then a deflection device 74, which is also equipped with beam-like air guide elements, followed by three beam-like air guide elements 76 which ensure that after the deflecting device, the paper web 11 assumes a satisfactory stable run. Downstream of the elements 76 is an infrared drying section 78, a floater-type drying section 80 and finally another infrared drying section 82. Thus, the paper web 11 assumes a V-shaped path. The two arms of the V-shaped path can be at different angles to one another, but should be at an angle between about 10° and about 60° to the horizontal.
An embodiment of a device according to the invention shown in FIG. 8, also includes coating applicator rolls 10 and 20, each having an applicator station assigned thereto. Downstream of the rolls 10 and 20 with respect to the direction A of travel of a paper web 11 through the device, two types of drying sections, i.e., infrared drying sections 86 and floater-type drying sections 88, are disposed at either side of a paper web 11 opposite to one another, with each type of drying section in alternating arrangement with respect to the direction of travel of the paper web 11. Downstream of these alternating dryers is a bank of beam-like air guide elements 90, followed by a floater-type dryer section 92 and then another bank of air guide elements 94 which guide the web 11 in a V-shaped path. Downstream of the guide elements 94 is another group of infrared 86 and floater-type 88 dryer sections. However, in this group of dryer sections, two identical type drying sections are disposed opposite one another. Other arrangements of dryers are also possible. Thus, first and second arms of a V-shaped path as shown in FIG. 8 could be configured identically.
An embodiment of a device according to the invention shown in FIG. 9 includes the elements 10, 20, 86, and 88 identical in function to elements 10, 20, 86, and 88, respectively, shown in FIG. 8. A floater-type drying section 96 deflects the paper web 11, resulting in a V-shaped path. However, the same types of drying sections are disposed on opposite sides with respect to the two arms of the V-shaped path.
In an embodiment of a device according to the invention shown in FIG. 10, a paper web 11 runs essentially in a straight line through the entire device through two applicator rolls 10 and 20, a bank of beam-like air guide elements 100, an infrared drying section 102, a floater-type drying section 104 and another infrared drying section 106.
In an embodiment of a device according to the invention shown in FIG. 11, a paper web 11 runs essentially in a straight line through the entire device through two applicator rolls 10 and 20, infrared dryers 108 and floater-type dryers 110, with these different dryers being disposed opposite one another. Disposed downstream of the alternating dryers is another floater-type dryer 112.
An embodiment of a device according to the invention shown in FIG. 12, also includes coating applicator rolls 10 and 20, each having an applicator station assigned thereto. Downstream of the rolls 10 and 20 with respect to the direction A of travel of a paper web 11 through the device, two types of drying sections, i.e., infrared drying sections 116 and floater-type drying sections 118, are disposed at either side of a paper web 11 opposite to one another similar to the configuration of drying sections shown in FIG. 9. Downstream of the first bank of alternating dryers is a floater-type dryer section 120 followed by another bank of alternating dryers 116 and 118. However, in contrast to the device shown in FIG. 9, in the device shown in FIG. 12, beam-like air guide elements are integrated into the elements of the infrared drying sections. As shown in FIG. 12a, the individual infrared dryer elements are designed in such a way that they can create a carrier-air cushion between themselves and the coated paper web. FIG. 12b shows another embodiment of an infrared drying section 116'.
An embodiment of a device according to the invention shown in FIG. 13 shows the applicator rolls 10 and 20 rotatably attached to the device and the associated application stations 10.1 and 20.1 in greater detail. In this embodiment a web 11 travels through the roll gap formed by the rolls 10 and 20 from beneath these roles and travels in an upward direction. The web 11 does not necessarily travel vertically; it can also be inclined to the vertical. The coating composition can be applied to one side or to both sides. The device includes downstream (with respect to the direction of travel A of the web 11 through the device) elements 130, 132, 133, 134, and 136, similar in function to the elements 40, 41, 42, 43, and 44, shown in FIG. 6.
FIGS. 14a to 14d show embodiments of beam-like air guide elements according to the invention.
With reference to FIG. 14a, a beam-like air guide element 150 has a single line of bores 152 from which air flows out. The bores 152 are disposed in a straight line.
With reference to FIG. 14b, a beam-like air guide element 154 has bores 156 displaced with respect to one another. In other words, two rows of bores 156 are disposed transversely to the direction of movement of a web through the device, i.e., along a straight line.
In an embodiment shown in FIG. 14c, two beam-like air guide elements 50 and 60 carry a paper web 11 therebetween. The direction of movement of the web 11 is indicated by an arrow A. The two air guides 50 and 60 have slits. The slits can extend over the entire width of the web 11 (i.e., over the entire length of the individual beam-like elements). Also, several such slits per beam-like element can be disposed behind one another. The slit in each beam-like element is always upstream with respect to the oncoming paper web 11. An air curtain illustrated by the arrows B flows from the slit.
In the embodiment shown in FIG. 14d, a beam-like air guide element 60 has air slits on both edge regions thereof which extend over the entire width of a paper web 11 and also over the entire length of the guide element 60. Here, again, arrows B are shown to indicate an air curtain exiting the slits. The guide element 60 has a box-like hollow body 60.1 therewithin extending over the width of the paper web. The box-like body 60.1 has a row of bores 60.2. Air which was introduced through the slits is aspirated through the bores 60.2 and then removed on a side of the box 60.1 (not shown). This configuration provides a stable air cushion. In order to create a uniform pressure of the air curtains a perforated plate 60.2 is provided in the hollow beam-like element 60.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications within the scope of the invention will be apparent to those skilled in the art. | A device for coating a paper web includes two applicator rolls disposed parallel to one another, forming a roll gap for the passage of a paper web therethrough. At least one applicator for applying a coating onto a surface of at least one of the rolls is also provided. The coating roll thereafter transfers the coating onto one side of a paper web disposed in the roll gap. Guide elements disposed downstream of the roll gap with respect to a direction of travel of the paper web through the device include at least one beam-like air guide element adapted to create an air cushion-between the paper web and a surface of the air guide element facing the paper web. The air guide element is disposed in such a manner as to deflect a paper web at least once downstream the roll gap. At least one air guide element is disposed directly downstream of the roll gap at a distance from the roll gap of about 0.3 times to about 1 time the diameter of at least one of the rolls. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a national stage of PCT/DE02/02227 filed Jun. 14, 2002, and based upon DE 101 29 845.5 filed Jun. 15, 2001 under the International Convention.
FIELD OF THE INVENTION
The present invention relates to a method for the production of an adhesive and an adhesive kit for joining similar or different metal surfaces or ceramics, especially in the field of biomedicine.
BACKGROUND OF THE INVENTION
Known bone cements for anchoring joints and repairing other bone defects consist of a synthetic material which as a rule is based on methylmethacrylate or related substances, in some cases with the addition of further esters of acrylic acid or methacrylic acid. Such bone cements are described e.g. in DE 196 41 775 A1. Frequently, a combination of benzoyl peroxide and dimethyl-p-toluidine is used as a catalyst in the liquid monomer, which is pointed out as a disadvantage in DE 196 35 205. Bone cements are usually prepared by mixing two components. One component contains the liquid monomer, the other is made up of a powdery polymer provided in the form of spherical particles having a diameter of approx. 100 μm.
Such bone cements or other adhesives used e.g. in dentistry are intended to endure for a very long time and usually do not allow the adhesive bond to be undone earlier, e.g. for inspection.
Another general problem with regard to materials to be polymerized consists in that heat is exothermally released during the polymerization. However, the bone cells which are in contact with said materials are damaged if the temperature rises above 50° C. The actual thermal stress put on body cells within the zone of contact with the polymerizing bone cement can only be predicted very inaccurately. It depends on the thickness of the cement layer applied, the thermal conductivity via the prosthesis components as well as the bone itself. Laboratory tests have shown that maximum temperatures up to 110° C. may be reached during the polymerization of commercially available cements under certain conditions, causing burns as a consequence. Improvements seem to be necessary in this respect.
Another problem of the bone cements known so far is due to the fact that residual monomer inevitably contained therein as well as other additives, e.g. the stabilizer hydroquinone (toxicity class 3) and the accelerator N,N-dimethyl-p-toluidine (toxicity class 2), may dissolve out, thus causing damage.
SUMMARY OF THE INVENTION
The object of the invention is to avoid current polymerization-linked components or effects with regard to adhesive bonds in the field of biomedicine, in addition to enabling a temporary biocompatible bond between metal and metal or metal and ceramics.
The inventive method for the production of a temporary adhesive solves the aforesaid problems by avoiding polymerization itself during the synthesis of the adhesive and by adding a special bioactive material. According to the invention, said method consists in that 15 to 50% by weight of a monomer-free polymethylmethacrylate (PMMA) whose average molar mass ranges between 3,000 and 200,000 daltons and whose acid value ranges between 10 and 350 mg KOH per g polymer is mixed with a biocompatible, organic solvent or solvent mixture for the PMMA and 0.05 to 80% by weight of a bioactive, vitreous-crystalline material with a particle size ranging between 0.05 and 20 μm is added to the mixture while stirring and at a temperature ranging between 10 and 50° C. until a flowable mixture is obtained whose open processing time ranges between 1 and 20 minutes, wherein the vitreous-crystalline material consists of 15–45% by weight CaO, 40–45% by weight P 2 O 5 , 10–40% by weight ZrO 2 and 0.7–3.5% by weight fluoride and contains apatite and calcium zirconium phosphate as main crystal phases and a glass phase as an auxiliary component, said main crystal phases jointly making up at least 35% by weight and said auxiliary components making up 5 to 15% by weight.
Further, 3 to 30% by weight of a biocompatible powder containing zinc and/or a totally or partially resorbable bioceramic material may be added to the mixture.
The mixture can be introduced in the body and set therein at body temperature since no polymerization reaction takes place within said mixture. For this purpose, a PMMA whose acid value has been modified and having a molar mass as indicated above is dissolved in a suitable solvent, e.g. ethyl acetoacetate or mixtures of ethyl acetoacetate with ethanol, which ethanol may contain water up to an amount of 4% by volume. The sticky, flowable component obtained in this way is mixed with a powder mixture of the vitreous-crystalline material and optionally e.g. ZnO and totally or partially resorbable and/or long-term stable bioceramic and optionally TiO 2 . The particle size of all powdery components ranges between 0.005 and 20 μm. As a result of the aforesaid procedure, a flowable, sprayable and spreadable mass is obtained ex vivo, which can be processed during a period of several minutes, e.g. 1–10 min, depending on the amount of powder contained therein.
DETAILED DESCRIPTION
It is preferred that a polymethylmethacrylate be used in an amount ranging between 30 and 35% by weight.
The average molar mass of the PMMA may preferably range between 20,000 and 80,000 daltons.
The acid value may preferably range between 25 and 65 mg KOH per g polymer. In this context, the acid value indicates the amount of KOH in mg required to neutralize 1 g of the polymer sample. It is an essential criterion as the number of free carboxyl groups of the polymer is important with regard to bonding to the metal components.
The acrylate whose acid value has been modified can be produced from methylmethacrylate and methacrylic acid by means of a suspension polymerization, wherein the ratio of the molar masses has to be selected such that the desired acid value is achieved. Alternatively, the polymer whose acid value has been modified can be obtained by alkaline saponification of a polymer consisting of methylmethacrylate and ethylmethacrylate. The ethylmethacrylate makes up 2 to 10 moles, preferably 6 moles.
A preferred vitreous-crystalline material contains 23–39% by weight CaO, 40–45% by weight P 2 O 5 , 20–35% by weight ZrO 2 and 1–6% by weight fluoride and contains apatite and calcium zirconium phosphate as main crystal phases and a glass phase as an auxiliary component, said main crystal phases jointly making up at least 35% by weight and said auxiliary components making up 5 to 15% by weight.
Another preferred vitreous-crystalline material contains 23–39% by weight CaO, 40–45% by weight P 2 O 5 , 20–35% by weight ZrO 2 and 1–3% by weight fluoride and in addition 0.1–6% by weight Na 2 O and contains apatite and calcium zirconium phosphate as main crystal phases and a glass phase as an auxiliary component and a sodium zirconium phosphate phase as an additional auxiliary component. Said main crystal phases jointly make up at least 35% by weight and each of said auxiliary components can make up 5 to 15% by weight.
In addition, the vitreous-crystalline material according to the invention may contain 0.1 to 6% by weight magnesium oxide and/or potassium oxide and the corresponding additional phases.
The amount of Na 2 O, MgO and/or K 2 O contained preferably ranges between 1 and 6% by weight. The corresponding secondary crystal phase, i.e. sodium zirconium phosphate, preferably makes up 5 to 10% by weight.
The vitreous-crystalline material is produced by preparing a mixture of suitable substances, i.e. 15–45% by weight CaO, 40–45% by weight P 2 O 5 , 10–40% by weight ZrO 2 and 0.7–3.5% by weight fluoride. Advantageously, the fluoride is added in the form of CaF 2 . The aforesaid components are combined with one another, subjected to suitable, mostly multi-stage thermal treatment programs (holding stages in the range between 400 and 1,500° C.) and finally melted at between 1,550 and 1,650° C. in a suitable crucible material, preferably consisting of a Pt/Rh alloy. The melt is poured and once it has solidified the mass is cooled down to room temperature in air (spontaneous cooling) or in a cooling furnace, depending on its intended use. Finally, the material is ground.
In general, the terms “glass ceramic” and “vitreous-crystalline material” used herein cannot always be clearly defined. Both crystalline and vitreous and/or X-ray amorphous phases are provided in a thoroughly mixed state. It is of no importance for the present invention whether one phase is located adjacent to the other or one phase encloses the other.
The term “main crystal phase” as used herein refers to a crystalline phase which is contained in at least twice the amount of a secondary phase, concentrations of approx. 15% and below, preferably below 10% by weight, being referred to as secondary phases.
The particle size is measured by means of laser granulometry.
The bioceramic material which may be used in addition to said vitreous-crystalline material is preferably selected from among materials containing sodium, potassium, calcium, magnesium hydroxyl ions or hydroxyl components, fluoride, silicate and/or orthophosphate. A preferred bioceramic material contains crystalline phases of Ca 2 KNa(PO 4 ) 2 . By adding resorbable bioceramics, porous structures can be achieved which may have osteoconductive effects and at the same time act as a support. The gradual dissolution of the bioceramic particles depends on the structure thereof an can be adjusted as desired. Advantageous materials include e.g. a material produced according to DE 19744809 C1 or materials containing Ca 2 KNa(PO 4 ) 2 or similar phases. If long-term stable, bioactive ceramics or glass ceramics are used instead, one of the crystalline phases should be apatite. An advantageous glass ceramic is based on apatite/wollastonite according to DD 247574A3.
In order to obtain a material with higher X-ray density, it is recommended that a material be admixed to the adhesive according to the invention which consists of the following components or contains the same in amounts above 30% by weight: CaZr 4 (PO 4 ) 6 and/or CaTi 4 (PO 4 ) 6 . It is of no importance for the intended use of the adhesive whether calcium zirconium phosphate and/or calcium titanium orthophosphate is provided in an amorphous or rather in the more typical crystalline form.
Further, it may be advantageous that TiO 2 be added as an additional inorganic filler, preferably in an amount ranging between 0.1 and 10% by weight and preferably in the form of its modification rutile, thereby achieving considerably higher strengths.
The biocompatible powder containing zinc used may be zinc oxide or a zinc soap. Zinc soaps, which belong to the group of metallic soaps, are salts containing the rests of long-chain fatty acids, oleoresin acids and naphthenic acids such as stearates, palmitates, oleates, linoleates, resinates, laurates, octanoates, ricinoleates, 12-hydroxystearates, naphthenates, tallates, etc.
The setting reaction can also be controlled via the formation of zinc soaps and the supply of water from the surrounding tissue. There is no need to add water.
Due to its structure, the adhesive has a certain stickiness with respect to metal oxides and, as a result, adheres better to the outer oxide layer of e.g. ceramic surfaces or implants made of titanium alloys.
The inventive method may include the incorporation of medicines, e.g. antibiotics, which advantageously may be added to individual components of the mixture, e.g. the vitreous-crystalline or the bioceramic material, or added into the mixture as a separate component. Preferably, gentamicin is added in an amount ranging between approx. 0.5 and 2% by weight, preferably 0.8 and 1.3% by weight, relative to the total weight of the adhesive.
A particular advantage of the adhesive according to the invention consists in that it is a monomer-free adhesive which is easy to mix, whose thixotropy and/or pore size is adjustable and which does not release any toxic substances into the surrounding tissue. In particular, the adhesive has absolutely no toxic effect since monomers as well as the usual stabilizers and accelerators are avoided. Another advantage consists in that the adhesive does not set during the mixing process, i.e. in 1 to 10 minutes, preferably 4–5 min, but remains plastic during 3 to 8 min on average.
All the aforesaid features enable the adhesive to be evenly spread on a metal or ceramic surface, resulting in a uniform thickness of the adhesive layer applied thereto. In this way, a uniform contact between the surfaces to be joined to one another by the adhesive can be ensured. Processing errors occur much more seldom.
The setting process is brought about by the formation of chelates. Said chelates may be formed by a reaction with the Zn 2+ ions added, but in part also with the soluble components of the two ceramics as well as components contained in the surface of the materials to be joined.
The temporary adhesive according to the invention enables a bond between metal and metal, which metals can be the same or different, and metal and ceramics to be established for a certain period of time, which may be particularly desirable in dentistry, e.g. when fixing metallic implants to ceramic crowns or metallic implants to gold crowns. In many cases, it is advantageous to undo such joints after several weeks or months or even up to 2 years in order that the dentist may evaluate certain effects on the tissue surrounding the implant or remove deposits in the area around and below the crown. Adhesive bonds established by means of known bone cements or adhesives usually cannot be undone in a targeted manner, i.e. without damaging any or several of the crown, the implant or the surrounding gum.
The strengths of the adhesive according to the invention are such that the patient's use of their dentures is in no way restricted.
The invention further relates to an adhesive kit based on polymethylmethacrylate characterized by the following components provided separate of one another:
a) 15 to 50% by weight of a monomer-free polymethylmethacrylate (PMMA) whose average molar mass ranges between 3,000 and 200,000 daltons and whose acid value ranges between 10 and 350 mg KOH per g polymer; b) 5 to 40% by weight of a biocompatible organic solvent or solvent mixture for the PMMA; c) 0.05 to 80% by weight of a vitreous-crystalline material with a particle size ranging between 0.05 and 20 μm consisting of 15–45% by weight CaO, 40–45% by weight P 2 O 5 , 10–40% by weight ZrO 2 and 0.7–3.5% by weight fluoride and containing apatite and calcium zirconium phosphate as main crystal phases and a glass phase as an auxiliary component, said main crystal phases jointly making up at least 35% by weight and said auxiliary components making up 5 to 15% by weight.
Said kit may further contain 3 to 30% by weight, relative to the total weight of the kit, of a biocompatible powder containing zinc and/or a resorbable bioceramic material according to DE 197 44 809 or EP 0541546 and/or a long-term stable bioceramic material according to DD 247 574.
In addition, the bone cement kit may contain amounts of TiO 2 , either mixed with component c) or provided separately, as well as an X-ray contrast medium, either mixed with component c) or provided separately, preferably up to 30% by weight CaZr 4 (PO 4 ) 6 or CaTi 4 (PO 4 ) 6 or mixtures thereof.
The biocompatible solvent included in the adhesive kit according to the invention is ethyl acetoacetate or a mixture of ethyl acetoacetate with ethanol, which ethanol may contain water up to an amount of 4% by volume.
It is advantageous that the biocompatible powder containing zinc be zinc oxide or a zinc soap.
The kit according to the invention is sterilized using ethylene oxide or by means of radiation and provided in a sterilized form.
The kit may further contain medicinal components, which are either mixed with the individual components or provided separately, particularly antibiotics.
The invention will hereinafter be explained in more detail by means of examples. All percentages are by weight.
EXAMPLE 1
Production of the Vitreous-Crystalline Material Apatite/CZP1
A mixture having the following composition is prepared (Code: Apatite/CZP1):
25.88 CaO 28.44 ZrO 2 43.68 P 2 O 5 5.00 CaF 2 .
In doing so, the amount of CaO can be added in the form of 62.79 CaHPO 4 and the required amount of P 2 O 5 can be incorporated in the form of 10.51 ml of an 85% H 3 PO 4 . First, CaHPO 4 , ZrO 2 and CaF 2 are thoroughly mixed, then the phosphoric acid is added, the mixture is left to react and subsequently ground in a mortar, the process including holding stages at 120° C. and 170° C. lasting 4 hours each and intended to dry the product. The reaction mixture obtained in this way is filled into a Pt/Rh crucible, heated up to 400° C., held at this temperature for 1 hour, heated up to 800° C., held at this temperature for 1 hour, cooled and ground in a mortar. The material pretreated in this way is now melted in a Pt/Rh crucible, the melting process including holding times of 15 min at 800, 1,000, 1,300, 1,500 and finally 1,600° C. respectively, and poured onto a steel plate (room temperature).
Once the melt has solidified, part of the material obtained is milled in an agate mill and particles below 43 μm are separated by sieving and analyzed by means of X-ray diffractography. The result (X-ray diffractogram) shows that the crystal phases apatite (fluoroapatite/hydroxyapatite) and calcium zirconium phosphate [CaZr 4 (PO 4 ) 6 ] are clearly detectable in the vitreous-crystalline product. The remaining part of the solidified melt is comminuted until a particle size of 0.05–20 μm is achieved.
EXAMPLE 2
Production of the Vitreous-Crystalline Material Apatite/CZP2
A mixture is prepared according to the instructions of Example 1, except that sodium oxide is added as an additional component (Code: Apatite/CZP2). Specifically, the following components are mixed:
59.93 CaHPO 4 27.10 ZrO 2 3.42 Na 2 O 5.00 CaF 2 and 9.56 ml of an 85% H 3 PO 4 .
Processing is done as in Example 1. At the end of the last temperature holding stage, the melt is poured out of the crucible onto a steel plate.
Once the melt has solidified, part of the material obtained is milled in an agate mill and particles below 43 μm are separated by sieving and analyzed by means of X-ray diffractography. The result (X-ray diffractogram) shows that the crystal phases apatite (fluoroapatite/hydroxyapatite) and calcium zirconium phosphate [CaZr 4 (PO 4 ) 6 ] and sodium zirconium phosphate [NaZr 2 (PO 4 ) 3 ] are detectable in the vitreous-crystalline product.
The remaining part of the solidified melt is comminuted until a particle size of 0.05–20 μm is achieved.
EXAMPLE 3
Coefficients of Expansion of Apatite/CZP1
A vitreous-crystalline material according to Example 1 was produced (Apatite/CZP1). The material was milled in a mill lined with zirconium oxide until a D 50 -value of 8 μm was achieved. The ground material was combined with a 5% polyvinylalcohol (PVA) solution, the ratio of ground material to PVA solution being 90 to 10% by weight, and the mixture was compression-moulded into a rod applying a force of 4.7 kN. The resulting compact was sintered at a temperature of 1,050°.
Then, the thermal coefficient of expansion (CE) of the relatively dense moulded body obtained in this way was determined:
CE in the range of 27–400° C.:
1.90 * 10 −6 degrees Celsius −1
CE in the range of 50–400° C.:
1.86 * 10 −6 degree Celsius −1
CE in the range of 30–300° C.:
1.45 * 10 −6 degree Celsius −1
CE in the range of 30–400° C.:
1.88 * 10 −6 degree Celsius −1
CE in the range of 30–600° C.:
2.6 * 10 −6 degree Celsius −1
CE in the range of 30–800° C.:
3.2 * 10 −6 degree Celsius −1
EXAMPLE 4
Chemical Stability of Apatite/CZP1 in the Alkaline Range
A vitreous-crystalline material according to Example 1 was produced (Apatite/CZP1). Subsequently, the material was ground in a mortar until a particle size fraction of 315–400 μm was obtained.
The chemical stability of the granulated material obtained in this way was compared to those of a basic glass (Ap40 glass ) and a glass ceramic made from said basic glass and based on apatite and wollastonite (Ap40 cryst. ) [i.e. with a chemical composition corresponding to (% by weight): 44.3 SiO 2 ; 11.3 P 2 O 5 ; 31.9 CaO; 4.6 Na 2 O; 0.19 K 2 O; 2.82 MgO and 4.99 CaF 2 ].
First, the specific surface areas according to BET were determined using krypton as measuring gas. The following results were obtained:
Apatite/CZP1:
0.364 m 2 /g
Ap40 glass :
0.018 m 2 /g
Ap40 cryst. :
0.055 m 2 /g.
It can be seen that the vitreous-crystalline material used in the adhesive according to the invention has a certain open porosity compared to the basic glass and the glass ceramic made therefrom. These differences were taken into account in the solubility tests by adjusting the ratio of surface (sample) to volume of solvent (TRIS HCl buffer solution) to a constant value of 5 cm −1 .
The solvent used was a 0.2M TRIS HCl buffer solution, pH=7.4, at 37° C. The samples were stored therein for 120 hours at a temperature of 37° C. Then the samples' total solubility was determined by determining the individual ions (Ca, P, Zr) in the solution by means of an ICP measurement. The following results were obtained:
Apatite/CZP1:
4.1–5.1 mg/l
Ap40 glass :
318–320 mg/l
Ap40 cryst. :
75.2–82.0 mg/l.
The above values impressively demonstrate the high chemical stability of the novel material used in the adhesive according to the invention under simulated physiological conditions, which is a known method for determining long-term stability in vitro.
EXAMPLE 5
Chemical Stability of Apatite/CZP1 in the Acid Range
The same procedure as in Example 4 was carried out, except that a 0.2M TRIS HCl buffer solution having a pH value of 6.0 and a temperature of 37° C. was used for measuring. In this way, an infection during the wound healing process or at a later stage causing the pH value to fall from the physiological value of 7.4 down into the acid range can be simulated.
The following total solubility values (Ca, P, Zr) were determined by means of ICP:
Apatite/CZP1:
16–19 mg/l
Ap40 glass :
505–518 mg/l
Ap40 cryst. :
117–125 mg/l.
The above values impressively demonstrate the high chemical stability of the material used for the invention under simulated conditions corresponding to those during an inflammation reaction. According to the test results, the absolute solubility values of the material according to the invention increase to a much smaller extent than those of the basic glass and the glass ceramic based on apatite/wollastonite which rise quite dramatically.
EXAMPLES 6 to 8
In order to determine the tensile strength, an adhesive consisting of 30% polymer preparation, combined with a mixture of 60% by volume ethanol and 40% by volume ethyl acetoacetate as well as 35% by weight powder, was used to fix caps of In-Ceram (Vita Zahnfabrik), Galvanogold (Wieland Edelmetalle) and Express 2 (Ivoclar) to 4 mm high truncated cones of titanium with an upper diameter of 4.5 mm. The powder was made up of ZnO, TiO 2 and a vitreous-crystalline material according to Example 1. The samples were stored in water for 24 hours at 37° C. and subsequently their tensile strength was determined by pulling them apart at a rate of 1 mm/min using a Zwick all-purpose testing machine.
Example 6
Example 7
Example 8
Cap
Empress 2
Galvanogold
In-Ceram
Tensile
35 N
131 N
129 N
strength after
storage in
water for
24 hours at 37°
After storage
77 N
78 N
in water for
10 weeks
Compared to the known Havard Cement (zinc phosphate cement) whose tensile strength ranges between 300 and 600N, the tensile strengths of a material such as Empress 2 in connection with titanium are lower by approx. one order of magnitude and therefore well suitable for a temporary fixing.
Now that the invention has been described: | The invention relates to a method for the production of an adhesive and an adhesive kit for joining similar or different metal surfaces or ceramics, especially in the field of biomedicine. The objective of the invention is to avoid polymerization-linked by-products and disadvantageous effects, in addition to enabling a temporary biocompatible bond between metal and metal or metal and ceramics. The inventive method consist in using a monomer-free polymethylmethacrylate which is mixed with a suitable, non-toxic solvent and a bioactive vitreous-crystalline material with a particle size ranging from 0.05–20μ, consisting of 15–45 wt. % CaO, 40–45 wt. % P 2 O 5 , 10–40 wt. % ZrO 2 and 0.7–3.5 wt. % fluoride, having apatite and calcium zircon phosphate as main crystal phases and a glass phase as an auxiliary component until a flowable mixture is obtained. The invention also relates to an adhesive kit consisting of said components. Sufficient amounts of resistance are obtained for a temporary bond, enabling the bond to be neutralized when desired. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to containers for beverages. Specifically, the present invention relates to a beverage container having a body composed of a rigid material and ends composed of a polymer film.
2. Description of the Related Art
Restaurants and especially fast food restaurants have a strong need for disposable containers for beverages. Disposable containers for beverages are numerous and have certain advantages and disadvantages. These beverage containers run the gamut from glass to polyester to fiberboard to aluminum. Most such containers are recyclable which mitigates the disposability aspect of such containers. However, storage of such containers on site, for example at a fast food restaurant, presents a problem due to the need for a large storage space depending on the container. Also, the desire of most fast food restaurants to use fountain dispensers instead of prepackaged beverage containers eliminates containers such as aluminum cans from meeting the needs of these fast food restaurants. Another desire of fast food restaurants is to allow the fast food restaurant employee perform several tasks related to a customer's order while a beverage is being prepared for the customer which eliminates containers incapable of maintaining an open filling state without the assistance of an employee.
Stackable fiberboard cups have been the most popular solution to a fast food restaurant's needs, however, storage of the cups requires sufficient space in the tight confines of the "kitchen" of a fast food restaurant. Other solutions such as flexible pouches do not meet the open filling state requirement thereby occupying the time of a fast food employee at the beverage dispenser.
There still remains a need for a beverage container which occupies a minimal space during storage, is capable of maintaining an open filling state, and is large enough to contain a family size volume of beverage for transport from a fast food restaurant to a customer's work or home.
BRIEF SUMMARY OF THE INVENTION
One aspect of the present invention is a beverage container having a body, a top end and a bottom end. The body defines an interior of the container and has an interior and an exterior surface. The body is composed of a rigid material. The bottom end is composed of a polymer film and is sealed to the body. The top end is composed of a polymer film and is sealed to the body. The top end has a closeable access for filling the container with a beverage through the access before sealing for transport.
Another aspect of the present invention is a hybrid container for a beverage. The hybrid container includes a rigid body, a top end and a bottom end. The rigid body has a first sheet and a second sheet with each of the sheets having a plurality of side panels. The first sheet is attached to the second sheet at the first and last side panels of the plurality of side panels. The flexible plastic film bottom end is attached to a lower end of each of the first and second sheets. The flexible plastic film top end is attached to an upper end of each of the first and second sheets. The top end has a resealable opening for accessing the interior of the hybrid container. The plurality of panels of each of the sheets of the rigid body and the flexible plastic top and bottom ends allow for the hybrid container to be modified from a substantially flat state to an erected filling state.
It is a primary objective of the present invention to provide a container which may be stored substantially flat and then erected for filling.
It is an additional objective of the present invention to provide a hybrid container composed of a rigid material such as fiberboard and a flexible material such as a plastic film.
It is an additional objective to provide a hybrid container having a resealable opening.
Having briefly described this invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Several features of the present invention are further described in connection with the accompanying drawings in which:
There is illustrated in FIG. 1 a perspective view of a preferred embodiment of the hybrid container of the present invention in a open-filling state;
There is illustrated in FIG. 2 a side view of an alternative embodiment of the hybrid container of the present invention in a closed-prefilling state;
There is illustrated in FIG. 3 a side view of an alternative embodiment of the hybrid container of the present invention in a closed-prefilling state;
There is illustrated in FIG. 4 a side view of an alternative embodiment of the hybrid container of the present invention in a closed-prefilling state;
There is illustrated in FIG. 5 a side view of an alternative embodiment of the hybrid container of the present invention in a closed-prefilling state;
There is illustrated in FIG. 6 a perspective rear view of the hybrid container of FIG. 1;
There is illustrated in FIG. 7 a top plan view of the hybrid container of FIG. 1;
There is illustrated in FIG. 8 a perspective bottom view of the hybrid container of the present invention in a closed-prefilling state;
There is illustrated in FIG. 9 a perspective bottom view of the hybrid container of the present invention in an open-filling state;
There is illustrated in FIG. 10 a cross-section along line 10--10 of FIG. 9;
There is illustrated in FIG. 11 an interior view of the top of the hybrid container of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The novel hybrid container of the present invention is directed toward fulfilling the need for the short term .packaging of a beverage in a container with a self maintaining open filling state, and without a tremendous space requirement for storage. However those skilled in the pertinent art will recognize that other applications of the hybrid container of the present invention are well within the scope and spirit of the present invention.
As shown in FIG. 1, a hybrid container 20 generally includes a rigid body 22, a flexible plastic top end 24, a flexible plastic bottom end 26, a handle 28 and a resealing mechanism 30. The flexible plastic top end 24 has an opening 32 allowing for access to the interior 34 of the container 20. The interior 34 is accessed by the resealing mechanism 30.
The rigid body 22 may be composed of several different materials. A preferred material is a fiberboard coated with polyethylene on its interior and exterior surfaces. An alternative material is a mineral filled polyolefin material such as described in Andersson et al, U.S. Pat. No. 5,654,051 for a Packaging Material And Packaging Containers Produced Therefrom, issued on Aug. 5, 1997, which relevant parts are hereby incorporated by reference.
The rigid body 22 may be composed of first, second, third, fourth and fifth panels 36, 38, 40, 42, 44 on one side and a mirror set of panels 36', 38', 40', 42', 44', not shown, on the other side. The panels 36, 38, 40, 42, 44 are defined by a series of crease lines 50. Although the panels 36, 38, 40, 42, 44 may be of any size relative to each other, a preferred embodiment has panel 40 twice the size of panel 38 which is equal in size to panel 42.
A preferred embodiment of the hybrid container 20 is designed to contain two liters of a beverage product such as a cola drink. However those skilled in the pertinent art will recognize that the present invention may be designed to accommodate various volumes of product.
The panels 36, 38, 40, 42, 44 allow the container 20 to be substantially flat in a closed-prefilling state. The panels 36, 38, 40, 42, 44 also allow the rigid body 22 to bulge out during a filling state in which the opening 32 must stay open in order to fill the container 20 without the constant presence of a beverage filling operator, not shown. The operation of the container will be further described below.
In a preferred embodiment, panel 42 has a handle aperture 54 cut therethrough and a diagonal heat seal 52 which together form a handle 28 for use by a consumer. The heat seal 52 seals off the section of panels 42 and 42' from the interior 34 of the container 20. Additionally, panels 36, 36', 44 and 44' are all sealed from the interior 34 by a similar heat sealing along their respective crease lines 50.
The flexible plastic top end 24 may be attached to the rigid body 22 through various means. A preferred means is heat sealing of an overlapping portion, not shown, of top end 24 to rigid body 22. This is easily performed if rigid body 22 has a polyethylene coating thereon. Other contemplated attachment means include ultrasonic sealing, stitching, and adhesive sealing.
The top end 24 is generally one piece with a resealing mechanism 30 through the center which allows for an opening in the top end 24. The resealing mechanism may be a strip, or a series of strips or perforations which allow for the resealing and opening of the top end similar to a recloseable flexible pouch.
FIGS. 2-5 illustrate side views of various embodiments of the hybrid container 20 of the present invention with different top ends 24, and specifically different resealing mechanisms 30. FIG. 2 is similar to FIG. 1 except for the absence of a handle 28. FIG. 3 is similar to FIG. 1 except for the presence of zipper mechanism 56 for facilitating the opening and resealing of the top end 24. FIG. 4 is similar to FIG. 1 except that the handle 28' is built into the top end 24 and handle aperture 54' is cut through one or both sides of the top end 24 which come together upon resealing. More specifically, the arcuate portion of the top end 24 illustrated in FIG. 4 may only be present on one flap of top end 24 to prevent interference during filling of the container 20. FIG. 5 is similar to FIG. 1 except that a clip 58 is used as a handle. The clip 58 has a first side 60 and a second side 62 which mate to provide a channel 66 in which a portion of the top end 24 is held. The clip 58 may act as a handle.
FIG. 6 illustrates the bulging of the container 20 during the open filling state during which top end 24 may be further defined as having a first flap 67 and a second flap 68. FIG. 7 illustrates a top plan view looking into the container 20. As shown, panels 36 and 36' are sealed to each other and panels 44 and 44' are sealed to each other. Although panels 42 and 42' appear to be sealed to each other, only the top portion above diagonal seal 52 are exactly sealed to each other. The dashed lines show the bulging of the rigid body 22.
FIGS. 8 and 9 illustrate the bottom of the container 20. The flexible plastic bottom end 26 is sealed to the rigid body in a similar fashion as the top end 24. The bottom end and the top end may be composed of most flexible plastic materials. Such materials may include polypropylene, a blend of polyethylene, a nylon, a polyvinyl dichloride, and the like. A dashed line 66 designates the seal line of the bottom end 26 to the rigid body 22. As shown, the container is substantially flat in FIG. 8 while bulging in FIG. 9.
To illustrate the sealing of the bottom end 26 to the rigid body 22, FIG. 10 is cross section along line 10--10 of FIG. 9. The cross-section 70 may be similar to the cross-section for the top end 24 and the rigid body 22. A fiberboard layer 72 is coated with polyethylene layers 76 and 78 on both surfaces. The flexible plastic material layer 74 of bottom end 26 is attached to polyethylene layer 76. If the rigid body is composed of the afore-mentioned mineral filled polyolefin material, then layer 74 may be attached directly to a corresponding layer 72.
FIG. 11 illustrates the overlap in the interior of the upper area of the rigid body 22. The overlap area 80 divides all flexible plastic top end 24 from all rigid body 22. Such an overlap section would form an interior perimeter inside the interior 34 of the container 20. A similar overlap area 80 may be found where the bottom end 26 meets the rigid body 22.
In operation, a gross of hybrid containers 20 may be stored substantially flat in a closed-prefilling state at a restaurant such as a fast food restaurant. The closed-prefilling state is best illustrated in FIG. 8. When a consumer desires a "family" size volume of a beverage for a "To-Go" order, then a single container 20 is removed from the gross and compressed from both sides into an erect open-filling state in which resealing mechanism. 30 is not sealed thereby providing opening 32. The erect container is placed under a standard beverage dispenser and filled without the constant presence of a restaurant employee. This is possible because of the rigid body 22 which maintains the container 20 in its open-filling state when erected thereby allowing the restaurant employee to perform other tasks related to the To-Go order from the consumer. Once the container. 20 is filled (most dispensers are capable of being set for a predetermined volume such as two liters), the resealing mechanism is sealed thereby closing the opening allowing for the transportation of the beverage with a low probability of spillage of the beverage. The container 20 only needs minimal barrier properties due to the consumption of the beverage shortly after purchase from the restaurant.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims. | A novel hybrid beverage container having a rigid body and flexible polymer film ends is disclosed herein. The hybrid container may be folded in a closed state for storage, and erected for a filling state. The top end of the container has a recloseable access for filling and sealing the container with a beverage. The container may also have a handle device. In one preferred embodiment, the rigid body is composed of a polyethylene coated fiberboard material. In another embodiment, the rigid body is composed of a mineral filled polyolefin. | 1 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457).
BACKGROUND OF THE INVENTION
This invention relates to a method and means for purifying the waste water present in Kraft pulp and paper mill wastes.
In the process of pulp and paper manufacture, a considerable amount of water is used. When this water is discharged, it carries varying degrees of pollution since only about 34% of it receives some form of treatment to remove the pollution. Treatment of pulp and paper waste is difficult and complicated because of the large quantities of water used by the mills which require large installations to remove small amounts of pollutants per unit volume. For example, a normal Kraft process mill will use 35,000 gallons of water per ton of pulp produced and a sulphite mill will use 63,000 gallons per ton. Also, many different waste streams originate in the plant. These streams vary in concentration and composition and with the type of processing. Since all of the waste streams require treatment, it becomes an economic puzzle whether to combine the wastes and treat them together or to treat them separately as they are being generated. For some of the waste materials, there is no known efficient method for treatment. The wastes which are in the waste streams are complex and numerous and each of them contributes different degrees of resistance to treatment and degradation in the waste treatment effort. Some materials can be removed or digested by biological systems. Others are toxic and very stable to most biological organisms. The color components that are produced by the lignins are very stable and cannot be removed by normal biological digestion processes.
Lignins and their colored degradation products can be precipitated by massive amounts of calcium salts, (such as lime), but this treatment does not remove the biochemical oxygen demand, (BOD), causing materials. Activated carbons, when used in excessively large amounts and in combination with lime may be effective in removing color and BOD. However, the method has economic limitations.
Past studies have shown that no single method is known that will treat the combined mill pulp and paper wastes. None of the present treatment procedures addresses the problem of the generated solids' disposal. All of the state of the art treatment efforts are aimed at the two major problems which are the economic reduction of BOD and the elimination of color. However, except for the lime treatment no other method for color removal has received serious consideration in the industry.
While the color problem alone has not been shown to be detrimental to the environment, as it does not consume oxygen from the receiving stream, it is objectionable because it can be seen. There is little data available on the effect on marine environment when exposed to bodies of water containing highly colored waste.
Industry is also searching for an inexpensive method to separate and recover the lignin materials. Lignins are useful since they can be competitive with petro chemicals as a source of chemical raw materials. This is especially true since lignin is a replenishable resource and therefore it may become an essential source for organic chemicals, plastics and combustible gases.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to provide useful method and means for purifying the water present in pulp and paper mill wastes obtained from a Kraft process mill.
It is another object of this invention to provide a relatively inexpensive method and means for purifying the water present in the waste of a paper mill using the Kraft process.
Still another object of the invention is to provide a novel and useful paper mill waste treatment system in which the waste water is purified for reuse and lignins are extracted.
The foregoing and other objects of the invention are achieved in an arrangement wherein Kraft pulp and paper mill waste waters are dumped into a settling tank and mixed there with activated carbon and quaternary ammonium compounds. The lignin-ammonium complex, together with other settleable materials are permitted to settle and form a sludge at the bottom of the settling tank. The supernatant fluid will be clean and recyclable water. The sludge is passed through a filter or other suitable equipment to separate the solids from the water. This water is also clean and recyclable.
To extract lignins and also to obtain activated carbon the solids are dissolved in methanol producing a slurry. The methanol dissolves the lignin and quaternary ammonium compound, but not the carbon or cellulosic solids. The slurry is then passed through a filter. The carbon and cellulosic solids remaining after the filtration step are pyrolyzed to produce activated carbon which can be returned to the settling tank. The liquid passing through the filter is treated with mineral acid which precipitates out the lignin. The precipitated lignin is then separated from the remainder of the solution by filtration. The remainder of the solution is passed through a distillation column whereby most of the methanol is stripped and recovered and can be used again. The remainder after the distillation is a mixture of the quaternary ammonium compounds and the mineral acid. The quaternary ammonium salt mixture is neutralized with caustic in the reconstitution tank to a pH of 5 to 8 diluted with water to a concentration of 1% quaternay ammonium compound salt, and returned into the settling tank for use again.
The novel features of the invention are set forth with particularity in the appended claims. The invention will best be understood from the following description when read in conjunction with the accompanying drawing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In converting raw material, such as wood, into pulp, which is done in making paper, large quantities of high quality water are used which become contaminated with many materials along with lignins, a basic ingredient of wood. It has been customary to discharge the contaminated water into a nearby body of water or stream, because there is no economically feasible method of completely removing the lignins and other contaminants. This effluent degrades the body of water into which it is discharged in two ways. The lignins are highly colored, so that they discolor the water, which is objectionable aesthetically and of unknown hazard to marine life. Further, the lignin degradation products and other contaminants compete with living organisms in the water for the available oxygen.
In accordance with this invention quaternary ammonium compounds are used to precipitate the lignins and colored lignin degredation products and activated carbon is used to adsorb other contaminants whereby purified and reusable water is obtained.
A quaternary ammonium compound can be represented as follows: ##STR1##
The R's can be carbon chains with appropriate attendant hydrogen atoms or simply methyl groups or hydrogen atoms. The anion [X - ] group can be hydroxyl, phosphate, acetate, sulphate, chloride, etc. The N is a Nitrogen atom.
The class of quaternary ammonium compounds of interest here are water miscible. They contain one, two or three methyl (CH 3 ) groups and at least one alkyl group containing 8 to 18 carbon atoms. Such compounds include:
Mono methyl trialkyl ammonium acetate
Dimethyl distearyl ammonium phosphate, and
Trimethyl cetyl ammonium chloride.
Laboratory tests verify that certain compounds of this class precipitate lignins and colored lignin degradation products from a large variety of aqueous wastes (prior art teaches that amines can be used to extract color impurities but only in a complex multi-phased solvent system).
Additional tests indicate certain alkyl propylene diamines also function in this manner. The quaternary ammonium compound is added to the lignin containing water on the basis of substantially one weight equivalent of quaternary ammonium compound to one weight equivalent of lignin. The basis of the weight determination is done either as a result of a chemical analysis of the waste water or by a spectrophotometric analysis, whereby the concentration of the lignin is determined as well as the amount of the quaternary ammonium compound which is to be added. This is described more fully below.
Referring now to the drawing, there is shown a schematic diagram for treating pulp and paper mill waste waters obtained from a Kraft process paper mill in accordance with this invention.
The pulp and paper mill waste waters are deposited in a settling tank 10, into which air may be introduced, if desired. Quaternary ammonium compounds together with activated carbon are added to the settling tank and mixed with the waste water.
The amount of activated carbon to be added is determined by running a test on a sample of the waste water to determine the chemical oxygen demand (COD) milligrams per liter. A weight of activated carbon of between 2 to 5 times the COD milligrams/liter is then added to the settling tank.
The mixture is agitated and allowed to stand for a period of time until sludge settles to the bottom of the settling tank. This sludge will be comprised of lignins and lignin waste products combined with the quaternary ammonium compound, cellulosic wastes and with the activated carbon which was added to absorb soluble impurities and clarify the water. The supernatant water may be removed from the settling tank since, as a result of the treatment given, it should be ready for recycling, (or disposal as clean water).
One percent solution of quaternary ammonium salt is added to the lignin containing waste liquor on the basis of color as follows:
A sample of the waste is taken (100 ml) and 1 ml of a 1% solution in water of quaternary ammonium compound salt added. The color is compared to the original with a spectrophotometer at a wave length of 450μ (pH 7.6). Additional quaternary ammonium salt is added until the color is lowered the proper amount (i.e., substantially colorless). The total amount of quaternary ammonium salt added is determined and calculated as the amount per 1000 gallons. This would then be added to a known quantity of waste liquor, agitated and the color examined again with the spectrophotometer, if more quaternary ammonium is needed it can then be added.
If it is further desired to recover the lignins from the sludge, and also to obtain activated carbon for use in the water purification process, then the sludge on the bottom of the settling tank is applied to a first filter 12 to separate the solid matter from the water. The water is clean water and can also be recycled or disposed of. The solid material or cake is transferred to a dissolving tank 14. Into the dissolving tank 14 there is introduced methanol sufficient to dissolve the quaternary ammonium compounds of lignin. It has been determined that quaternary ammonium compounds of lignins are soluble in a neutral solution of methanol. The minimum methanol concentration should equal the water concentration in the cake. That is the minimum concentration of methanol and is most cost effective. Another quantitive measure can be to add methanol until the slurry turns a dark brown in color which is the lignin color. The solids and added methanol form a slurry which is applied to a second filter 16. The second filter separates the solid undissolved matter from the solution of methanol and quaternary ammonium lignins. The solid matter is transferred to a pyrolysis furnace 18, where it is pyrolized and produces activated carbon. The activated carbon from the pyrolysis furnace may then be fed back to the settling tank to treat a new batch of waste water.
The solution which passes through the filter 16 is applied to a lignin precipitation tank 20. It has been found that when a solution of methanol is acidified, quaternary ammonium compounds remain soluble therein, but lignins are insoluble therein. Accordingly, a mineral acid such as sulphuric, or hydrochloric, or phosphoric acid, is added to the solution in the lignin precipitation tank to adjust its pH to 2 to 2.5. As a result the solution in the lignin precipitation tank forms a slurry.
The slurry is applied to a third filter 22. The third filter separates the solid material, comprising lignin solids from the quaternary ammonium compound salt and acidified methanol mixture. The lignin solids are thus recovered.
The mixture of methanol and quaternary ammonium compounds is applied to a methanol recovery unit 24, which comprises a distillation column. The distillate is methanol, which is condensed in a condenser and the methanol output is fed back to the dissolving tank 14. The residual comprises quaternary ammonium compound salts. This is transferred to a reconstitution tank 28. The reconstitution tank is used to adjust the concentration and the pH, between 5.0 to 8.0, of the quaternary ammonium compound salt. The concentration remaining from the methanol unit is approximately 10 to 15%. This must be diluted with water to approximately 1% solution for pumpability and to keep the quaternary ammonium salt dissolved. The reconstituted quaternary ammonium compound can then be again introduced into the settling tank 10.
Efficacy of the new process, compared to treatment methods in the prior art can be compared as follows:
______________________________________ Approximate Percent Lignins Dosage and Color (lb/1000 gal) Removed______________________________________Lime Treatment 12.5 70Lime (4#) + Carbon (2.5#) 6.5 90Bio-oxidation + Carbon 10.5 92Carbon Alone 42 to 168 95+Quaternary Ammonium Compound 3 100______________________________________
The foregoing shows the efficacy of the process in accordance with this invention when compared with the treatment methods of the prior art.
There has accordingly been shown and described herein a novel, useful and economical method and means for treating pulp and paper mill wastes, whereby the large quantities of polluted water resulting may be purified for reuse, and also lignins and activated carbon may be recovered. | A method and means for purifying the waste water from paper and pulp mill wastes obtained from a mill using the Kraft process by first precipitating lignins and lignin derivatives from the waste stream with quaternary ammonium compounds, removing other impurities by activated carbon produced from the cellulosic components of the water, and thereafter separating water from the precipitate and solids. The activated carbon also acts as an aid to the separation of the water and solids. If recovery of lignins is also desired, then the precipitate containing the lignins and quaternary ammonium compound is dissolved in methanol. Upon acidification, the lignin is precipitated from the solution. The methanol and quaternary ammonium compound are recovered for reuse from the remainder. | 2 |
This application is a continuation of application Ser. No. 07/522,084 filed on May 14, 1990, which is a continuation of application Ser. No. 07/423,581 filed on Oct. 17, 1989, which is a continuation of application Ser. No. 07/271,421 filed on Nov. 15, 1988, all three applications now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image stabilization device for a camera, wherein image displacement caused by a camera-shake due to hand trembling can be eliminated by driving an imaging system such as an optical system.
2. Related Background Art
Various conventional image stabilization devices have been proposed. In such a device, an image displacement on an imaging surface of e.g., a film due to camera-shake caused by a hand trembling or the like, is suppressed such that a lens system as an object to be controlled is driven in a vibration suppression direction.
For example, a camera vibration (normally, a camera vibration with respect to a photographing optical axis) is detected as an acceleration signal, and this acceleration signal is integrated by a signal processing system to obtain a displacement signal (or a velocity signal). The lens system is driven by these signals in a lens vibration suppression vibration of an image).
FIG. 18 is a diagram of a typical arrangement showing a principle of an image stabilization device including a conventional signal processing system of the type described above. An accelerometer (Rot Acc) 1 detects a camera (not shown) vibration with respect to a photographing optical axis as an acceleration signal. A detected acceleration signal a is integrated into a velocity signal v by a first integrator 2. The velocity signal v is then converted into a displacement signal d by a second integrator 3.
An actuator 5 is operated to drive a radially displaceable camera imaging system 4 (normally, an imaging lens system) in the radial direction to achieve image stabilization in accordance with the displacement signal d.
A variable resistor 6 constitutes a position detecting means for detecting an actual positional displacement of the imaging system 4. A signal from this position detecting means is fed back to an input system of the actuator, thereby constituting a feedback loop for matching radial position of the imaging system 4 with the vibration displacement.
A spring 8 urges the imaging system 4 toward a one-side limit position of its movable range during inactivation of the actuator 5. Unnecessary movement of the imaging system 4 during inactivation of the actuator 5 is thus prevented.
In the conventional arrangement described above, a radial position of the imaging system 4 upon activation of the actuator 5 is determined by a balance between the spring force of the spring 8 and a driving force generated by the actuator 5. In order to optimize an image stabilization start operation, an imaging system centering means as an initial position setting means is generally provided due to the presence of the spring 8.
The above operation will be briefly described. An overall radial stroke of the imaging system 4 in the above arrangement is defined as l, and an origin is defined as a central position (i.e., an /2 position) of the imaging system 4. Then, the imaging system 4 is urged at the -l/2 position by the spring 8 during inactivation of the actuator 5. When the actuator 5 is activated, the imaging system 4 must start an image stabilization operation while being kept urged at the -l/2 position if the centering means is not arranged. As the imaging system 4 is located at a negative limit position, it cannot be further moved in the negative direction. Therefore, a good image stabilization effect cannot be expected.
In order to arbitrarily move the imaging system in the positive or negative direction upon activation of the actuator 5, the imaging system centering means is added to immediately move the imaging system 4 from the -l/2 position to the origin at the activation start timing of the actuator 5 (This operation is called a centering operation). Image stabilization is started after the centering operation by the imaging system centering means is completed. A centering operation time is ideally almost zero. However, in practice, the centering time is about 30 to 100 msec due to an operating time of the imaging system 4 and a vibration damping time after centering.
The centering operation is utilized not only at the start of actuator operation but also during image stabilization control as needed. That is, the stroke of the actuator 5 and outputs from the integrators 2 and 3 are not infinite, and the imaging system may be moved to the stroke limit position within the camera (lens barrel) due to large vibrations. In this case, when the outputs from the integrators 2 and 3 are reset to re-start the centering operation of the imaging system, subsequent image stabilization control can be optimized.
In recent years, most of the commercially available cameras incorporate AF (Auto Focus) units for automatically focusing an image so as to reduce, for example, a load from a photographer. An application of the image stabilization device to an AF camera poses some problems. Prior to a description of these problems, an AF unit will be generally described.
Various types of AF unit are available. A single-lens reflex camera having many interchangeable lenses employs a TTL passive AF unit to cope with focal lengths of various interchangeable lenses from a wide angle lens to a telephoto lens. FIGS. 19(a) to 19(c) show operating states of such a TTL passive AF unit. This AF unit includes a field lens 11 located on an optically equivalent plane to a film surface as a primary imaging plane, a photographing lens 27, and secondary imaging lenses 13a and 13b. Two beams passing through different areas of the photographing lens 27 are independently sampled, and space images formed on the primary imaging plane are formed on distance measuring sensors 14a and 14b again. Each distance measuring sensor comprises a line photoelectric transducer element such as a BASIS or a CCD. Automatic gain control (AGC) for adjusting the photographing condition to the brightness of external light is generally performed by changing an accumulation time of the photoelectric transducer element.
In this AF unit, an in-focus state (FIGS. 19(a) and 20(a)), a forward focus state (FIGS. 19(b) and 20(b)), and a backward focus state (FIGS. 19(c) and 20(c)) are detected in accordance with distances between the object images on the distance measuring sensors 14a and 14b. A photographing lens drive mechanism (not shown) is driven in accordance with the detected state, and automatic focusing or focus adjustment can be achieved.
A camera with a telephoto lens is inevitably vibrated by the operator's hands or even if a tripod is used due to wind. This problem also occurs even in a camera having an AF unit. It is therefore also effective to mount an image stabilization device in the AF camera.
The following problem is posed when the image stabilization device and the AF unit as independent components are mounted in a camera.
Assume that the imaging system is moved to perform image stabilization in the radial direction while a distance measuring operation of the AF unit is being performed. In this case, displacement of an image formed on the distance measuring sensor can be prevented to obtain a good distance measuring effect. However, in the image stabilization device for centering the imaging system to the origin at the start of image stabilization operation, if the centering operation and the distance measuring operation are simultaneously performed, an error often occurs.
A cause of this erroneous operation will be described below.
Assume that charge is accumulated by the photoelectric transducer element serving as a distance measuring sensor, and that the imaging system centering operation of the image stabilization device is being performed. Under these conditions, an object image on the distance measuring sensor is abruptly moved during the accumulating operation. For this reason, a distance measuring disable state occurs due to movement of the image, thus causing a distance measuring error.
The above problems are also presented in association with another device for detecting photographic information by using a photoelectric transducer means.
In addition, the centering operation poses a problem in association with an exposure operation of a silver chloride film or the like. That is, an image stabilization operation must be effective during film exposure. However, when the imaging system 4 is deviated from the center of the stroke and then a release operation is started, the imaging system 4 tends to abut against the stroke end on the side having a small stroke margin. Then, the image stabilization operation tends to be invalidated. For this reason, it is preferable that every time the release operation is started, the centering operation is performed to locate the imaging system 4 at the center of the stroke, and the release operation is started.
However, the centering operation requires a period of 30 to 100 msec. If the release operation is started during the centering operation, the imaging system 4 is moved independently of hand trembling while the shutter is open and the film is exposed to light. Therefore, an image which is displaced in the direction of movement of the imaging system 4 is recorded on the film surface.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above situation, and has as its object to provide an image stabilization device comprising an automatic focus detecting means for receiving a beam from an object to use the beam as image information, image processing means such as exposing means, a displacement compensation means for driving an imaging system so as to compensate displacement of an image, initial setting means for setting the imaging system to an initial state for driving by the displacement correcting means, and interlocking control mean for preventing simultaneous driving of the image processing means and the initial setting means, wherein a problem caused by simultaneous driving of the image processing means and the initial setting means can be eliminated, and the image processing means can be optimally operated.
The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description of preferred embodiments in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a circuit arrangement of a camera having an image stabilization device according to a first embodiment of the present invention;
FIG. 2 is a flowchart for explaining control procedures of a CPU in the image stabilization device shown in FIG. 1;
FIG. 3 is a block diagram showing a circuit arrangement of a camera having an image stabilization device according to a second embodiment of the present invention;
FIG. 4 is a block diagram showing a hardware arrangement of a camera according to a third embodiment of the present invention;
FIGS. 5 and 6 are flowcharts for explaining control procedures of an image stabilization device of the third embodiment;
FIG. 7 is a block diagram showing a hardware arrangement of a camera according to a fourth embodiment of the present invention;
FIG. 8 consisting of FIGS. 8A, 8B and 8C, is a flowchart for explaining control procedures of an image stabilization device according to the fourth embodiment;
FIG. 9 is a block diagram showing a circuit arrangement of a camera having an image stabilization device according to a fifth embodiment of the present invention;
FIG. 10 is a flowchart for explaining control procedures of a CPU of the image stabilization device of FIG. 9;
FIG. 11 is a block diagram showing a circuit arrangement of a camera having an image stabilization device according to a sixth embodiment of the present invention;
FIG. 12 is a block diagram showing a hardware arrangement of a camera according to a seventh embodiment of the present invention;
FIGS. 13 and 14 are flowcharts for explaining control procedures of an image stabilization device according to the seventh embodiment;
FIG. 15 is a block diagram showing a hardware arrangement of a camera according to an eighth embodiment of the present invention;
FIGS. 16 and 17 are flowcharts for explaining control procedures of an image stabilization device according to the eighth embodiment;
FIG. 18 is a diagram showing an arrangement of a conventional image stabilization device;
FIGS. 19(a) to 19(c) and FIGS. 20(a) to 20(c) are views for explaining operating states of a conventional passive AF unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
FIG. 1 is a block diagram showing an image stabilization device for a camera according to a first embodiment of the present invention. The same reference numerals as in FIGS. 18 to 19(c) denote the same parts in FIG. 1, and a detailed description thereof will be omitted.
This embodiment exemplifies a single-lens reflex camera having an AF unit.
A central position of a quick return mirror 9 is constituted by a half mirror or a pattern mirror as a combination of a total reflection portion and a transparent portion for distance measurement. Light incident on a photographing lens is partially transmitted through the quick return mirror 9 at a predetermined ratio. A sub mirror 10 guides the light passing through the quick return mirror 9 to a distance measuring optical system. The single-lens reflex camera also includes a field lens 11, a fixed aperture 12, a pair of secondary imaging lenses 13, and a pair of line photoelectric transducer elements 14 serving as distance measuring sensors.
A sensor accumulation controller 15 controls the distance measuring sensors 14. A known central processing unit (CPU 1 ) 16 for an AF unit calculates a defocus amount on the basis of a distance measuring principle (described with reference to FIGS. 19(a) to 20(c)) using data from the distance measuring sensors 14 and performs focus adjustment upon driving of a focus adjusting driver 17.
A central processing unit (CPU 2 ) 18 for an image stabilization device performs the centering operation upon operation of an image stabilization start switch (not shown), as shown in a flowchart of FIG. 2. The output port of a parallel I/O (interface) 19 is connected to a one-shot circuit 20. The input port of the parallel I/O 19 is connected to the Q output of an RS flip-flop 21. The one-shot circuit 20 outputs an "H" pulse when an output from the parallel I/O 19 goes high.
The set (S) input terminal of the RS flip-flop 21 is connected to the output terminal of the one-shot circuit 20. The reset (R) input terminal of the flip-flop 21 is connected to a gate circuit 22. The Q output of the flip-flop 21 is connected to the reset input terminals of the integrators 2 and 3, a gate circuit 26, and the parallel I/O 19.
The gate circuit 22 serves as a priority circuit for eliminating an unstable state (R input=S input="H") of the RS flip-flop 21 and giving a priority to the S input over the R input.
A centering reference power source 24 generates a voltage for holding the imaging system 4 at the center (origin) in the stroke range and is arranged such that a voltage as a sum of the voltage of the centering reference power source 24 and an output voltage of the integrator 3, both of which are added by an adder 23, is applied to the operational amplifier 7.
A reset circuit 25 generates a reset output (="H") when the imaging system 4 comes close to the origin The input terminal of the reset circuit 25 is connected to the position detecting means 6. The output terminal of the reset circuit 25 is connected to the R input of the RS flip-flop 21 through the gate circuit 22.
An arrangement of the reset circuit 25 will be described in detail. The reset circuit 25 includes comparators 25a and 25b. Each comparator generates an output of "H" level when an input voltage applied to the + or noninverting terminal thereof is higher than the input voltage applied to the - or inverting terminal thereof. Otherwise, the comparator generates an output of "L" level. The reset circuit 25 also includes reference power sources 25c and 25d.
If a voltage of the centering reference power source 24, a voltage of the reference power source 25c, and a voltage of the reference power source 25d are defined as V 24 , V c , and V d , respectively, and if the voltages V c and V d are determined to satisfy the following equation:
V.sub.24 =V.sub.c +V.sub.d /2 (1)
then an output from the reset circuit 25 is set at "H" level only when a voltage V of the position detecting means 6 falls within the following range:
V.sub.c <V<V.sub.c +V.sub.d (2)
that is, an output from the comparator 25a is set at "H" level and at the same time an output from the comparator 25b is set at "L" level.
The gate circuit 26 controls a sensor accumulation controller 15 to inhibit an accumulating operation of the distance measuring sensors 14 when a Q output from the RS flip-flop 21 is set at "H" level.
An operation of the device having the above arrangement will be described below. FIG. 2 is a flowchart showing control procedures of the CPU 2 18 for the image stabilization device.
Assume that an output Q from the RS flip-flop 21 is set at "L" level, that the integrator 3 is connected to the operational amplifier 7 through the switch circuit 23, and that an image stabilization feedback system constituted by the components 1 to 8 and an automatic focus adjusting system constituted by the components 9 to 17 are rendered operative. Under these assumptions, the automatic focus adjusting system repeats the following operations:
(1) Accumulating operation of the distance measuring sensors 14;
(2) Calculation of defocus amount by using data from the distance measuring sensors 14 under the control of the CPU 1 16; and
(3) Driving of the focus adjusting driver 17 on the basis of the defocus amount calculated in step (2).
Centering of the imaging system 4 in the image stabilization system will be described below.
The CPU 2 18 for image stabilization detects an input from a switch (not shown) or saturation of outputs from the integrators 2 and 3 and sets an output of the parallel I/O 19 to be "H" level, thereby starting a centering operation. The one-shot circuit 20 outputs an "H" pulse when the parallel I/O 19 goes high. The RS flip-flop 21 is set in response to this "H" pulse, and a Q output from the flip-flop 21 goes high. When this output Q is set at "H" level, the integrators 2 and 3 are reset. When this output is set at "H" level, the integrators 2 and 3 are reset, and their outputs are cleared to 0. An instruction voltage applied to the operational amplifier 7 is given by only the voltage from the centering reference power source 24. For this reason, a feedback force toward a position designated by the voltage of the reference power source 24, that is, the force acting toward the origin of the imaging system 4, is applied to the components 4 to 8. This operation is called a centering operation. When the Q output from the flip-flop 21 is kept high, an accumulating operation of the distance measuring sensors 14 under the control of the sensor accumulation controller 15 is inhibited by the gate circuit 26. Therefore, distance measurement during centering can be prevented.
When the imaging system 4 comes sufficiently close to the origin as the reference position by the centering operation and the voltage V from the position detecting means 6 falls within the range given by inequality (2), an output from the reset circuit 25 goes high At the same time, the one-shot circuit 20 generates an output pulse. The Q output of the RS flip-flop 21 is reset to "L" level unless the gate circuit 22 inhibits such an operation. When the Q output is set at "L" level, reset inputs to the integrators 2 and 3 go low and a displacement signal d is output from the integrator 3. Therefore the centering operation is finished, and an image stabilization operation is started (restarted). In this case, an input to the gate circuit 26 also goes low, and accumulation inhibition of the distance measuring sensors 14 can be released.
In this embodiment, the Q output from the RS flip-flop 21 is input to the CPU 2 18 for image stabilization through the parallel I/O 19 to detect an end of centering upon monitoring of a change in logic level from "H" level to "L" level of the Q output, and the output from the parallel I/O 19 is set at "L" level (FIG. 2). The centering operation of the imaging system in the image stabilization device is thus completed.
Second Embodiment
An interlocking means is arranged to inhibit the operation of the sensor accumulation controller 15 for controlling the distance measuring sensors in the AF unit during the centering operation of the image stabilization device in the first embodiment described above. In a second embodiment shown in FIG. 3, an interlocking means is arranged to inhibit a centering operation of the image stabilization device during an operation of the sensor accumulation controller 15 in the AF unit.
A circuit arrangement of the second embodiment lies in a feature wherein a set (S) input and a reset (R) input to an RS flip-flop 21 for performing the centering operation are controlled by an output (a signal S' during sensor accumulating operation) from the sensor accumulation controller 15. More specifically, the set (S) input is obtained such that the signal S' is input to a one-shot circuit 20 through a gate circuit 22'. Only when the signal S' is set at "L" level, an "H" input is applied from the one-shot circuit 20 to the S terminal of the RS flip-flop 21.
The reset (R) input is applied as an "H" input to the R terminal when either the signal S' or an output from a reset circuit 25 is set at "H" level.
In the second embodiment, a circuit for inhibiting the operation of the sensor accumulation controller 15 during the centering operation of the image stabilization device is omitted. Other arrangements of this embodiment are substantially the same as those of the first embodiment shown in FIG. 1.
With the above arrangement, the centering operation of the image stabilization device is inhibited during the accumulating operation of the distance measuring sensors in the AF unit.
An operation will be described wherein an accumulating operation of the distance measuring sensors 14 is started during a centering operation. When the accumulating operation of the distance measuring sensors 14 is started, a center accumulating signal is set at "H" level by the sensor accumulation controller 15. An output from an OR gate 26' is set at "H" level accordingly, and the RS flip-flop 21 is reset. When the RS flip-flop 21 is reset and its Q output goes low, the centering operation is forcibly interrupted, and the image stabilization operation is re-started.
Third Embodiment
FIG. 4 is a block diagram showing a third embodiment of the present invention. A read-only memory (ROM) is often arranged in each interchangeable lens barrel to adjust differences in focal lengths in an AF single-lens reflex camera, while a camera body receives lens information required for focus adjustment and exposure control calculations from the lens barrel by means of communication. In this embodiment, an accumulation inhibiting means of photoelectric transducer elements in the AF unit utilizes communication.
Referring to FIG. 4, the camera includes a camera body 31, an interchangeable lens barrel 32, and a distance measuring portion 33 including distance measuring sensors and other optical systems. The distance measuring portion 33 corresponds to the components 10 to 15 in the embodiment of FIG. 1. A CPU 34 on the camera body side (to be referred to as a body CPU 34 hereinafter) performs distance measuring operations on the basis of data from the distance measuring portion 33 by means of communication and instructs the resultant lens drive amount to a CPU 40 on the lens barrel side (to be referred to as a lens CPU 40 hereinafter). The body CPU 34 also performs known control operations associated with data display and exposure. The body CPU 34 communicates with the lens CPU 40 through interfaces 35 and 41.
An image stabilization device in this embodiment is built into a lens barrel. An aperture driver 43 and a focusing driver 42 are also built into the lens barrel. An image stabilization CPU 37 controls image stabilization of the image stabilization device and the centering operation. An interface 38 is used as an interface for the image stabilization CPU 37. An image stabilization driver 39 corresponds to the components 1 to 8 in the embodiment of FIG. 1. The device of this embodiment is arranged to disable an operation of the lens CPU 40 under the control of the image stabilization CPU 37. The interfaces 38 and 41 in the lens barrel are connected in parallel with each other and are connected to the body interface 35 through signal terminals 36a to 36c arranged in a mount. Communication is serially performed, e.g., in units of bytes. A communication system is constituted as a communication synchronization clock line 36a for supplying a clock from the body, a signal line 36b for supplying a signal from the body to the lens, a signal line 36c for supplying a signal from the lens to the body, and a ground line (not shown).
An operation of the third embodiment will be described below.
An operation will be exemplified wherein image stabilization and automatic focus adjusting operations are being performed, but a centering operation is not performed.
In an automatic focus adjusting mode, the body CPU 34 sends a transmission request command for data required for distance measuring calculations (e.g., a focal length and sensitivity of a lens) to the lens CPU 40 through the interface 35. When the lens CPU 40 receives the command through the interface 41, the requested data is transmitted to the body in synchronism with a communication clock supplied from the body. The body CPU 34 enables the distance measuring portion 33, and the accumulating operation of the distance measuring sensors in the distance measuring portion 33 is performed. Distance measuring operations are performed on the basis of lens data and data from the distance measuring portion 33. The calculation results are used to calculate a focusing drive amount for achieving an in-focus state and this amount is supplied together with a focusing drive command (e.g., 20 H (H: hexadecimal notation)) to the lens CPU 40. The lens CPU 40 drives the focusing driver 42 in accordance with the received focusing drive amount. The above operations are the same as those known to a person skilled in the art. The foregoing operations are repeated to perform the automatic focus adjusting operation.
In this embodiment, the image stabilization CPU 37 monitors through the interface 38 communication between the body CPU 34 and the lens CPU 40. The image stabilization CPU 37 also monitors an integrator output in the image stabilization driver 39. The image stabilization driver 39 is arranged as an analog feedback system constituted by the components 1 to 8 of FIG. 1, and the image stabilization CPU 37 is not directly associated with a feedback loop.
A centering operation according to this embodiment will be described below.
When outputs from the integrators in the image stabilization driver 39 are saturated or the image stabilization CPU 37 receives a centering command (e.g., 30 H ) from the body CPU 34, the image stabilization CPU 37 performs the operations shown in a flowchart of FIG. 5. The image stabilization CPU 37 disables the lens CPU 40 and transmits a status word (e.g., 40 H ) representing that centering is being executed to the body CPU 34. The image stabilization CPU 37 supplies a centering operation execution signal to the image stabilization driver 39.
An operation of the body CPU 34 is shown the flowchart of FIG. 6. When the body CPU 34 receives the status word representing that centering is being executed, the body CPU 34 inhibits an accumulating operation of the distance measuring sensors in the distance measuring portion 33.
When the centering operation is completed, the image stabilization driver 39 automatically restarts an image stabilization operation, and the image stabilization CPU 37 transmits a status word (e.g., 50 h ) representing finishing of centering operation to the body CPU 34. At the same time, a disable state of the lens CPU 40 is cancelled.
When the CPU 34 receives the status word representing the finishing of centering operation, it releases inhibition of the accumulating operation of the distance measuring sensors and allows to an automatic focus adjusting operation restart.
The centering operation of the image stabilization device has a priority over a series of control operations of the AF unit. Therefore, simultaneous operations are inhibited, and a fail-safe AF operation can be assured.
In this embodiment, the image stabilization CPU 37 transmits to the body CPU 34 the status code representing that centering is being executed, thereby inhibiting the accumulating operation of the distance measuring sensors. However, the following arrangement may be alternatively employed. That is, when a lens communication and an accumulating operation of the distance measuring sensors are not simultaneously performed in the body sequence but may be serially performed and a hand shake line is provided to signal an end of communication preparation from the lens CPU to the body CPU (the hand shake line may be constituted by the synchronization clock line 36a), the image stabilization CPU 37 uses a means for forcibly setting the hand shake line in a communication disable state during centering to inhibit communication between the lens CPU and the body CPU. In this case, the body CPU is set in a communication wait state with respect to the lens CPU, and therefore the accumulating operation of the distance measuring sensors can be inhibited during centering. This system has an advantage in that only one hand shake line is used without employing a complex communication protocol.
Fourth Embodiment
In the third embodiment of FIG. 3, the operation of the lens CPU 40 is disabled by the image stabilization CPU 37 shown in FIG. 4. However, the control relationship of FIG. 4 may be reversed as in the relationship between the first and second embodiments.
The reversed relationship is realized in a fourth embodiment. A camera hardware arrangement of the fourth embodiment is shown in FIG. 7. The hardware arrangement of the fourth embodiment of FIG. 7 is substantially the same as that of FIG. 4 except that a lens CPU 40 is not connected to an image stabilization CPU 37.
An operation of the fourth embodiment will be described below.
Image stabilization and automatic focus adjusting operations in a centering disable state will be described below.
In the automatic focus adjusting operation, the body CPU 34 sends a transmission request command (e.g., 10 H ) for data required for distance measuring calculations to the lens CPU 40 through the interface 35. When the lens CPU 40 receives this command through the interface 41, the requested data is transmitted to the body in synchronism with a communication clock supplied from the body. The body CPU 34 enables the distance measuring portion 33 to cause the distance measuring sensors in the distance measuring portion 33 to start an accumulation operation. The body CPU 34 transmits a status code (e.g., 80 H ) representing that the accumulating operation is being executed. When the accumulating operation of the distance measuring sensors is finished, the body CPU 34 sends a status code (e.g., 90 H ) representing finishing of accumulating operation of the distance measuring sensor to the lens.
The body CPU 34 performs distance measuring calculations on the basis of the lens data received from the lens and the data from the distance measuring sensors in the distance measuring portion 33 to obtain a focusing drive amount so as to set the lens in the in-focus state. The focusing drive amount is sent together with a focusing drive command (e.g., 20H) to the lens CPU 40.
The lens CPU 40 drives the focusing driver 42 in accordance with the received focusing drive amount.
The above operations are known to those skilled in the art. The above operations are repeated to perform the AF operation.
Meanwhile, the image stabilization CPU 37 monitors through the interface 38 communication between the body CPU 34 and the lens CPU 40. When the image stabilization CPU 37 receives from the body a status word representing that the accumulating operation is being executed or representing finishing of the accumulating operation, it stores this status data in its internal memory. The image stabilization CPU 37 monitors to detect the saturation of the outputs from the integrators in the image stabilization driver 39.
An arrangement of the image stabilization driver 39 is the same as that of the third embodiment.
A centering operation will be described with reference to a flowchart in FIG. 8.
In this embodiment, a centering operation is started upon detection of the saturation of the outputs from the integrators in the image stabilization driver 39 or upon reception of a centering command (e.g., 30 H ) from the body CPU 34. For example, when the image stabilization CPU 37 detects the saturation of the outputs from the integrators in the image stabilization driver 39, the image stabilization CPU 37 refers to its internal memory to check if the distance measuring sensors in the body are accumulating charge.
If the memory content represents that the distance measuring sensors are not accumulating the charge, the centering operation is started. However, when the memory content represents that the accumulating operation is being executed, the image stabilization CPU 37 does not start the centering operation until the status word representing finishing of the accumulating operation of the distance measuring sensors is sent from the body CPU 34. When the status word representing finishing of the accumulating operation is received in this state, the image stabilization CPU 37 updates the status memory, thereby starting a routine for starting the centering operation.
When the centering operation is ended, the image stabilization driver 39 automatically restarts an image stabilization operation.
During the centering operation, when the status word representing that the accumulating operation of the distance measuring sensors is being executed is sent from the body and received by the image stabilization CPU 37, the image stabilization CPU 37 forcibly interrupts the centering operation and restarts an image stabilization operation (see a branch routine after starting of the centering operation in FIG. 8).
The centering operation of the image stabilization device can be effectively inhibited during the accumulating operation of the distance measuring sensors in the AF unit.
In the first to fourth embodiments, the centering and distance measuring operations are not simultaneously performed. According to the present invention, however, the accumulating signal of the distance measuring sensor may be cancelled during a centering operation, or signal projection may be inhibited during centering in an active AF unit. Any arrangement may be employed if image information received during the centering operation is not used in an AF operation to cause an operation failure.
Fifth Embodiment
FIG. 9 is a block diagram showing an image stabilization device for a camera according to a fifth embodiment of the present invention.
The same reference numerals as in FIG. 18 denote the same parts in FIG. 9, and a detailed description thereof will be omitted.
This embodiment exemplifies a case wherein the present invention is applied to a single-lens reflex camera. The single-lens reflex camera includes a quick return mirror 109, an aperture 110, a shutter 111, and a film 112. A known release control circuit 113 controls the quick return mirror 109, the aperture 110, and the shutter 111 when a release signal input through a parallel I/O 1 115 and a gate circuit 114 goes high. When the release operation is finished, a release operation end signal is output to a main CPU (CPU 1 ) 116 through the parallel interface I/O 1 115. A gate circuit 114 blocks a release signal output from the parallel I/O 1 115 to the release control circuit 113 when a Q output from a flip-flop 121 is set at "H" level.
The parallel I/O 1 115 interfaces signals between the main CPU (CPU 1 ) 116 and a release switch 117, the release control circuit 113, other switches (not shown), or other circuits (not shown).
The known main CPU (CPU 1/ ) 116 detects depression of the release switch 117 and generates a release signal. The CPU 1 116 also performs exposure and distance measuring calculations inside the camera.
The release switch 117 is connected to the parallel I/O 1 115 and a parallel I/O 2 119.
When a central processing unit (CPU 2 ) 118 for the image stabilization device detects depression of the release switch 117 through the parallel I/O 2 119, a centering operation is executed. The output port of the parallel I/O (PI/O 2 ) 119 is connected to a one-shot circuit 120, and an input port of the PI/O 2 119 is connected to the release switch 117 and the Q output of an RS flip-flop 121. The one-shot circuit 120 generates an "H" pulse when an output from the parallel I/O 2 119 goes high.
The set (S) input terminal of the RS flip-flop 121 is connected to the output terminal of the one-shot circuit 120, and the reset (R) input terminal of the flip-flop 121 is connected to a gate circuit 124. The Q output of the RS flip-flop 121 is connected to reset input terminals of the integrators 2 and 3, the gate circuit 114, and the parallel I/O 2 119.
The gate circuit 124 serves as a priority circuit for eliminating an unstable state (R input=S input="H") of the RS flip-flop 121 and giving a priority to the S input over the R input.
A reset circuit 123 generates a reset output (="H") when the imaging system 4 comes close to the origin. The input terminal of the reset circuit 123 is connected to the position detecting means 6, and the output terminal of the reset circuit 123 is connected to the R input of the RS flip-flop 121 through the gate circuit 124.
An arrangement of the reset circuit 123 will be described in detail below. The reset circuit 123 includes comparators 123a and 123b. When an input voltage applied to the +, or noninverting, input terminal of each comparator is higher than that to the -, or inverting, input terminal thereof, it generates an output of "H" level. Otherwise, the comparator generates an output of "L" level. The reset circuit 123 also includes reference power sources 123c and 123d.
If a voltage of the centering reference power source 122, a voltage of the reference power source 123c, and a voltage of the reference power source 123d are defined as V 22 , V c , and V d , respectively, and if the voltages V c and V d are determined to satisfy the following equation:
V.sub.22 =V.sub.c +V.sub.d /2 (3)
then an output from the reset circuit 123 is set at "H" level only when a voltage V of the position detecting means 6 falls within the following range:
V.sub.c <V <V.sub.c +V.sub.d (4)
that is, an output from the comparator 123a is set at "H" level and at the same time an output from the comparator 123b is set at "L" level.
An operation of the image stabilization device having the above arrangement will be described below. FIG. 10 is a flowchart for explaining control procedures of the CPU 2 118 of the image stabilization device.
A centering operation is preferably performed at the start of the image stabilization device and at the time of a release operation, as described above. The CPU 1 118 initializes the image stabilization device and repeats a loop until an image stabilization start switch (not shown) or the release switch 117 is depressed. When the image stabilization start switch or the release switch 117 is depressed, the CPU 2 118 sets an output from the parallel I/O 2 119 to be "H" level to start a centering operation. The main CPU 116 sets the release signal from the parallel I/O 1 115 to be "H" level. At this time, the main CPU 116 has a time lag given by software from ON detection of the release switch 117 to generation of the release signal.
The one-shot circuit 120 generates an "H" pulse when the parallel I/O 1 119 goes high. When the RS flip-flop 121 receives this "H" pulse, it is set in the set state, and its Q output is set at "H" level. A feedback force toward the position designated by the voltage from the reference power source 122, i.e., a force toward the origin for the imaging system 4, is applied to the components 4 to 8. When the Q output of the RS flip-flop 121 is set at "H" level, a release signal to the release control circuit 113 is inhibited by the gate circuit 114. Therefore, the release operation is not performed but inhibited. When the imaging system 4 comes sufficiently close to the origin as the reference position and the voltage V from the position detecting means 6 falls within the range defined by inequality (4), an output from the reset circuit 123 is set at "H" level, and at the same time, the one-shot circuit 120 generates an output pulse. The Q output from the RS flip-flop 121 is reset to "L" level unless the gate circuit 124 blocks the output pulse from the one-shot circuit 120. When the Q output is set at "L" level, reset inputs to the integrators 2 and 3 are set at "L" level. A displacement signal d is output from the integrator 3 to finish the centering operation and start (restart the image stabilization operation. At the same time, the input to the gate circuit 114 goes low, and blocking of the release signal is released.
In this embodiment, the Q output from the RS flip-flop 121 is input to the image stabilization CPU 2 118 through the parallel I/O 2 119. The CPU 2 118 monitors a change in logic level from "H" level to "L" level of the Q output and detects finishing of the centering operation. Then, the output from the parallel I/O 2 119 is set at "L" level (FIG. 10). The centering operation of the imaging system in the image stabilization device is thus completed.
In this embodiment, the overall release operation is limited. However, if a series of operations, e.g., up/down operation of the mirror 109 and stop-down step operation of the aperture 110, constitute a release sequence as in a single-lens reflex camera, this sequence may be interrupted at any time prior to opening of the shutter.
Sixth Embodiment
An interlocking control means is arranged such that the operation of the release control circuit 113 for controlling a release operation is inhibited during the centering operation of the image stabilization device in the fifth embodiment described above. However, an interlocking control means is arranged in the sixth embodiment such that the release operation has a priority over the centering operation as shown in FIG. 11. When the release operation is started, the centering operation is interrupted.
A circuit arrangement of the sixth embodiment lies in a feature wherein a reset (R) input to an RS flip-flop 121 is controlled by a signal (R') such as a mirror up end signal which is generated by a release control circuit 113' at any time prior to opening of the shutter during a release operation. A release control circuit in FIG. 11 of the sixth embodiment is represented by reference numeral 113' so as to distinguish it from the release control circuit 113 of FIG. 9.
The reset (R) input of "H" level is input to the R terminal when either the signal R' or an output from a reset circuit 123 is set at "H" level. In this embodiment, the circuit for blocking the release signal during centering operation of the fifth embodiment is omitted. Other circuit arrangements of the sixth embodiment are the same as those shown in FIG. 9. In the same manner as in the fifth embodiment, a main CPU 116 detects depression of a release button 7, waits for a predetermined period of time to give a priority to the centering operation over the release operation by software, and then generates a release signal. In this embodiment, however, a centering time varies according to the position of an imaging system 4 with respect to the stroke central position at the start of centering. In an extreme case wherein the imaging system 4 abuts against a stroke end, when centering is started, the centering time becomes longer than the wait time of a main CPU 116.
An operation for the above case will be described below.
When the wait time of the main CPU 116 has elapsed during the centering operation, a release signal is output from a parallel I/O 1 115 to the release control circuit 113'. The release control circuit 113' performs a series of release operations. When mirror up operation of the quick return mirror 9 is ended, the release control circuit 113' sets the R' signal to be "H" level. In this case, when the centering operation is not yet finished, an output from an OR gate 125 goes high accordingly, so that the RS flip-flop 121 is reset. After the Q output goes low, the centering operation is forcibly interrupted, and the image stabilization operation is restarted.
Seventh Embodiment
FIG. 12 is a circuit diagram showing an arrangement of a seventh embodiment of the present invention. A read-only memory (ROM) is often arranged in each interchangeable lens barrel to adjust differences in focal lengths in an AF single-lens reflex camera, while a camera body receives lens information required for focus adjustment and exposure control calculations from the lens barrel by means of communication. In this embodiment, an accumulation inhibiting means of photoelectric transducer elements in the AF unit utilizes communication.
Referring to FIG. 12, the camera includes a camera body 131, an interchangeable lens barrel 132, and a release control portion 133 corresponding to the component 3 in the fifth embodiment of FIG. 9. A CPU 134 on the camera body side (to be referred to as a body CPU 134 hereinafter) performs distance measuring operations on the basis of data from the distance measuring portion by means of communication and instructs the resultant lens drive amount to a CPU 140 on the lens barrel side (to be referred to as a lens CPU 140 hereinafter). The body CPU 134 also performs known control operations associated with data display and exposure. The body CPU 134 communicates with the lens CPU 140 through interfaces 135 and 141.
An image stabilization device in this embodiment is built into a lens barrel. An aperture driver 143 and a focusing driver 142 are also built into the lens barrel. An image stabilization CPU 137 controls image stabilization of the image stabilization device and the centering operation. An interface 138 is used as an interface for the image stabilization CPU 137. An image stabilization driver 139 corresponds to the components 1 to 8 in the embodiment of FIG. 1. The interfaces 138 and 141 in the lens barrel are connected in parallel with each other and are connected to the body interface 135 through signal terminals 136a to 136c arranged in a mount. Communication is serially performed, e.g., in units of bytes. A communication system is constituted by a communication synchronization clock line 136a for supplying a clock from the body, a signal line 136b for supplying a signal from the body to the lens, a signal line 136c for supplying a signal from the lens to the body, and a ground line (not shown).
In this embodiment, data transmission from the lens side to the body side is controlled by the lens CPU 140. The image stabilization CPU 137 monitors only communication between the body CPU 134 and the lens CPU 140 and does not perform data transmission to prevent collision of serial lines. However, the image stabilization CPU 137 is arranged to transmit a status code representing whether centering is being executed to the body CPU 134 through the lens CPU 140.
A release operation of the seventh embodiment will be described with reference to flowcharts of FIGS. 13 and 14.
FIG. 13 is a flowchart showing an operation of a release sequence of the body CPU 134.
FIG. 14 is a flowchart showing an operation of the image stabilization CPU 137.
When a release switch (not shown) is depressed, the body CPU 134 starts a release sequence.
The body CPU 134 sends out a release sequence command (e.g., 10 H ) representing that the release sequence is started. When the image stabilization CPU 137 receives this command through the interface 138, the image stabilization CPU 137 sends a status code (e.g., 40 H ) representing that the centering operation is being executed to the body CPU 134 through the lens CPU 140. The image stabilization CPU 137 then sends a centering execution signal to the image stabilization driver 139 to start a centering operation. The image stabilization CPU 137 waits until the end of the centering operation. When the centering operation is completed, the image stabilization CPU 137 sends a centering end command (e.g., 50 H ) to the body CPU 134 through the lens CPU 140 and waits until a release operation is started again. When the centering operation is completed, the image stabilization driver 139 automatically starts (restarts) the image stabilization operation.
Meanwhile, the body CPU 134 sends out to the lens CPU 140 a "stopping-down steps" command (e.g., 20 H ) for designating stop-down steps determined by exposure calculations beforehand. When the lens CPU 140 receives this command, the aperture driver 143 is operated to perform a stop-down operation by the designated steps.
The quick return mirror in the body is moved upward through the release control portion 133. When a centering operation is represented by a communication signal from the lens side, the release operation is interrupted until the status representing completion of centering operation is transmitted from the lens side.
When the status representing completion of centering is transmitted, the release operation is restarted to control the shutter through the release control portion 133. A "full aperture" command (e.g., 30 H ) is sent to the lens side so that the quick return mirror is then moved downward, and the aperture is set in a full aperture state. When the lens CPU 140 receives this command, the aperture driver 143 is operated to set the aperture in a full aperture state.
The body CPU 134 winds the film by one frame, and the shutter is charged, thereby completing the release operation.
In this embodiment, the centering operation of the image stabilization device has a priority over the release operation to inhibit simultaneous processing thereof. Therefore, a fail-safe release operation is assured.
In this embodiment, the status code representing that the centering operation is being executed is sent from the image stabilization CPU 137 to the body CPU 134 to inhibit the release operation. When lens communication and the release operation are not simultaneously performed in the body sequence but may be serially performed and a hand shake line is provided to signal an end of communication preparation from the lens CPU 140 to the body CPU 134 (the hand shake line may be constituted by the synchronization clock line 136a), the image stabilization CPU 137 uses a means for forcibly setting the hand shake line in a communication disable state during centering to inhibit communication between the lens CPU 140 and the body CPU 134. In this case, the body CPU 134 is set in a communication wait state with respect to the lens CPU 140, and therefore the release operation can be inhibited during centering. This system has an advantage in that only one hand shake line is used without employing a complex communication protocol.
In this embodiment, the body side is arranged to interrupt the release operation after the mirror up operation. However, the release operation interruption may be performed any time prior to the opening of the shutter during the release operation.
Eighth Embodiment
The release operation on the body side is interrupted by the image stabilization device of the lens side during centering operation in the seventh embodiment of FIG. 12. However, this relationship may be reversed as in the relationship between the fifth and sixth embodiments.
The reversed relationship will be described with reference to an eighth embodiment. A camera hardware arrangement is shown in FIG. 15. The hardware arrangement of FIG. 15 is substantially the same as that of FIG. 12 except that the lens CPU 140 is not connected to the image stabilization CPU 137.
An operation of the eighth embodiment will be described with reference to flowcharts of FIGS. 16 and 17.
FIG. 16 is a flowchart showing an operation of a release sequence of the body CPU 134, and FIG. 17 is a flowchart showing an operation of the image stabilization CPU 137.
Unlike the seventh embodiment wherein the status code representing that the centering operation is sent from the lens side to the body side, a control start command (e.g., 60 H ) is sent from the body side after a mirror up operation. When a centering operation is kept continuous upon reception of this command by the lens stabilization CPU 137, the centering operation is forcibly interrupted. The operation of the eighth embodiment will be described in more detail below.
The operation of the body CPU 134 until the mirror up operation is the same as that of the seventh embodiment. Meanwhile, the image stabilization CPU 137 receives a release sequence start command to start a centering operation. The lens CPU 140 drives the aperture driver 143 to perform a stopping-down operation by predetermined steps.
The image stabilization CPU 137 repeats a loop until a communication signal is sent from the body CPU 134 or centering operations ends upon starting of the centering operation.
When the centering operation is completed, the image stabilization driver 139 automatically starts (restarts) the image stabilization operation. The image stabilization CPU 137 restores a release operation wait state. If a communication signal is sent from the body CPU 134 prior to the end of centering operation, the flow advances to a branch step in FIG. 17. If a communication signal from the body CPU 134 represents a command except for the shutter control start command, the image stabilization CPU 137 restores a loop for waiting for a communication signal from the body CPU 134 or a centering operation. If the communication signal from the body CPU 134 represents the shutter control start command (60 H ), the image stabilization CPU 137 forcibly interrupts the centering operation and restores a state for waiting for the next release operation. After the body CPU 134 sends out the shutter control start command (60 H ), it controls the shutter. The subsequent operations are the same as those of the seventh embodiment, and a detailed description thereof will be omitted.
The centering operation of the image stabilization device during the release operation can be appropriately inhibited.
The present invention is not limited to the particular embodiments described above. Various changes and modifications may be made within the spirit and scope of the invention.
In each of the third, fourth, seventh, and eighth embodiments, the image stabilization unit, the focusing driver, and the aperture driver portion are built into one lens. However, only the image stabilization unit may be separated from the focusing driver and the drive lens portion and may be combined with a conventional extender to constitute an image stabilization adapter. In this case, an image stabilization function can be advantageously added to interchangeable lenses having no image stabilization functions.
In each of the third, fourth, seventh, and eighth embodiments, the image stabilization CPU is independent of the lens CPU. However, these CPUs may be replaced with one CPU.
The present invention is not limited to the single-lens reflex camera but can be extended to a leaf shutter camera. Various modifications may be made for the communicating means and the release sequence in each of the seventh and eighth embodiments.
In each embodiment described above, the present invention is applied to the relationship between the centering operation and the automatic focus adjusting operation or exposure operation. However, the present invention may be applied to a relationship between the centering operation and any other operation. For example, when a spot photometric technique for measuring 2 to 3% of the frame is used while a camera with a telephoto lens having a very long focal length is held by hand to take a picture, a desired object cannot be appropriately shot because of hand trembling. The image stabilization device is very effective in such a case since it can stabilize a finder image. However, when an image is greatly shifted by the centering operation of the imaging system in the image stabilization device, the photometric technique is used to measure light of a small portion of the frame to result in a photometric error. Therefore, the present invention is applied to prevent the centering and spot photometric operations from being simultaneously performed. Therefore, a spot photometric system can thus be effectively utilized.
The present invention is not limited to- a camera using a silver chloride film but can be effectively utilized for a video camera and an electronic camera having a mechanical or electro-optical shutter. That is, in a so-called electronic camera for recording an image on an image pickup element such as a CCD in a video floppy disk or a memory, inhibition of an accumulating operation of the image pickup element during the centering operation, and inhibition of the centering operation during the accumulation operation can prevent image displacement during the centering, thus providing a great advantage.
The present invention is not limited to the image stabilization devices of the above embodiments but can be applied to any image stabilization device which drives an imaging system (including an imaging surface) to an initial position for preventing the image deviation by centering the imaging system or the like. The present invention may include any arrangement wherein an operation of an image processing means, such as an automatic focus detecting means or an exposing means, which receives a beam from an object and utilizes the beam as image information is not simultaneously effected with a driving of the image system to an initial state so as to compensate for displacement of the image. | An image stabilization device includes image processing means for receiving a beam from an object and utilizing the beam as image information, blur correcting means for driving an imaging system to correct blurring of an image, initial setting means for setting the imaging means to an initial drive state of the blur correcting means, and interlocking control means for inhibiting a simultaneous operation of the image processing means and the initial setting means. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of European Application No. 02257634.2 filed on Nov. 5, 2002.
TECHNICAL FIELD
[0002] The present invention relates to mobile communications.
BACKGROUND OF THE INVENTION
[0003] In a code division multiple access (CDMA) system for mobile telecommunications such as a Universal Mobile Telecommunications System (UMTS), a mobile user terminal may be in a region in which soft-handover (also known as soft-handoff) is possible. In a soft-handover scenario, the signal from a mobile user terminal can be received by more than one cell of a network.
[0004] For soft-handover to work, one important aspect is to have measurement reporting by the mobile user terminal (sometimes referred to as user equipment, UE) of e.g. the strength of signals received from cells above a predetermined threshold. The measurement reporting from the mobile user terminal is controlled by the UMTS terrestrial radio access network (UTRAN) by way of sending reporting criteria to the mobile user terminal. Each base station has different reporting criteria (i.e. reporting criteria may differ on a per cell basis). It is necessary that the correct reporting criteria be used to give up-to-date measurement reporting. The reporting criteria normally consists of event-triggered conditions.
[0005] For inter-frequency handover (i.e. from one set of frequency bands to another) and inter-radio access technology handover (i.e. from one radio access technology to another, often referred to as inter-RAT handover, e.g. from a UTRAN network to a General Packet Radio Service (GPRS) network), measurement reporting criteria are also needed by the mobile user terminal in order to make a measurement report to the UTRAN network.
[0006] The known approach is that the serving radio network controller (RNC) controlling communications with the mobile user terminal has to know the reporting criteria of every cell it controls as well as neighboring cells controlled by the drift radio network controller. In object oriented design of a radio network controller (RNC), the reporting criteria is stored in each cell server within the radio network controller (RNC).
[0007] There are several problems with the known approach as follows. Firstly, any change in the reporting criteria in a cell as a result of a change in a neighboring cell associated with another radio network controller (the drift radio network controller) requires communication from the drift radio network controller to the serving radio network controller via an operations and maintenance center (OMC-U). This is a tedious manual update procedure, and is prone to human error. The task is even more complicated if the serving radio network controller and drift radio network controller are under the control of different vendors. There is no standard interoperability when a serving radio network controller is controlled by an operations and maintenance center of one vendor and another by an operations and maintenance center of another vendor.
[0008] Secondly, it is likely that the reporting criteria are the same for most cells in a network. The reporting criteria only needs to be customized for each cell in certain relative small areas (e.g. densely urban areas).
[0009] Thirdly, as shown in FIG. 1 the reporting criteria of different cells controlled by a radio network controller (RNC) are stored in different servers, (server # 1 (denoted 11 in FIG. 1 stores the data for cell number 1 to cell number I, and server # 2 stores the data for cell number i+1 to cell number j) within the radio network controller. In order to retrieve the reporting criteria for a cell, an internal query mechanism needs to be set up and the information is obtained (by a system controller 15 ), using this mechanism, from one of the servers or another 11 , 13 . In the worst case scenario, there will thus be a lot of internal traffic if the reporting criteria are stored in different servers and this will thus reduce the radio network controller performance.
[0010] Fourthly, using an object-orientated query mechanism within the radio network controller (RNC), as shown in FIG. 2 each call for reporting criteria of a cell requires a system object 17 to query the appropriate cell object 19 which itself queries an associated set of reporting criteria 21 for that cell. Accordingly, a large amount of memory is required in the radio network controller to store the reporting criteria information for each cell.
SUMMARY OF THE INVENTION
[0011] An embodiment of the present invention provides a method of providing to a mobile user terminal a set of measurement reporting criteria to be applied by the mobile user terminal in respect of a predetermined cell of a radio telecommunications network, the network comprising a plurality of cells and a controller, the method comprising the controller selecting the set of criteria from stored sets of criteria, one set of which is a default set for cells under the control of the controller, and another set of which is a cell-specific set of criteria.
[0012] In an embodiment of the invention the network is a Universal Mobile Telecommunications System (UMTS) network, the controller being a Radio Network Controller (RNC) controlling a plurality of base stations each of which has at least one associated cell.
[0013] In an embodiment, reporting criteria are obtained by, within the controller, a system object being directed to a cell object, each cell object having a pointer to the stored set of reporting criteria for that cell, at least two cell objects pointing to the same set of reporting criteria. Alternatively, reporting criteria are obtained by, within the controller, a system object being directed to the default set of reporting criteria upon determination that the cell object for the cell has no pointer to another stored set of reporting criteria.
[0014] The stored sets of criteria further comprise a set of criteria applicable to a subset of the cells controlled by the controller, the subset comprising at least two cells.
[0015] In an embodiment, the network comprises a further controller controlling further cells, the further controller being operative to provide to the controller the set of reporting criteria applicable to one of the further cells in response to a request from the controller. Preferably the request is a call set up request.
[0016] In an embodiment for a cell controlled by the serving radio network controller, the measurement reporting criteria information may be on cell level (i.e. different for different cells) or at a higher applicable to some or all the cells controlled by a radio network controller. Two level or multi-level measurement reporting criteria are thus provided. The number of reporting criteria objects, and hence the amount of queries between objects, required in the radio network controller is reduced. In consequence, the performance of the radio network controller is enhanced.
[0017] Embodiments of the present invention have several advantages. A need to perform manual input by the operator of measurement reporting criteria for each cell is overcome. The number of objects required to store the measurement reporting criteria is reduced. The amount of inter-server traffic within a radio network controller in looking up reporting criteria for cells is reduced and thus radio network controller performance is improved. Furthermore, the amount of duplicated information in a database in the radio network controller is reduced.
[0018] Improvements are thus provided in the provision of measurement reporting criteria at a radio network controller for use by a mobile user terminal for soft-, inter-frequency, or inter-radio access technology handovers. Radio network controller performance is increased in dealing with soft-handover, inter-frequency handover and inter-radio access technology handover situations.
[0019] In some embodiments, a cell controlled by a radio network controller other than the serving radio network controller will provide the measurement reporting criteria information when a radio connection is established to the cell in the soft-handover case. Communication is provided of the measurement reporting criteria from neighboring radio network controller (RNC) while setting up radio connections. This will ensure that the serving radio network controller does not have to contain all the measurement reporting criteria information of cells belonging to other radio network controllers (RNC) obtained via the operations and maintenance center (OMC-U). There is thus improved inter-operability between radio network controllers (RNCs) from different vendors. Use of explicit signalling is possible for the serving radio network controller to request measurement reporting criteria from the radio network controller which controls the cell or contains the cell information, particularly in the case of inter-RAT and inter-frequency handovers.
[0020] An embodiment of the present invention also provides a radio telecommunications network comprising a plurality of cells and a controller, and operative to provide to a mobile user terminal in respect of a predetermined cell a set of measurement reporting criteria to be applied for that cell, the controller comprising storage means operative to store sets of criteria, one set of which is a default set for cells under the control of the controller, and another set of which is a cell-specific set of criteria, and selection means operative to select the set of criteria applicable to the cell.
[0021] An embodiment of the present invention also provides a radio telecommunications controller operative to provide for a mobile user terminal in respect of a predetermined cell of a telecommunications network a set of measurement reporting criteria to be applied for that cell, the controller comprising storage means operative to store sets of criteria, one set of which is a default set for all under the control of the controller, and another set of which is a cell-specific set of criteria, and selection means operative to select the set of criteria applicable to the cell.
BRIEF DESCRIPTION OF THE DRAWING
[0022] An embodiment of the present invention will now be described by way of example and with reference to the drawings, in which:
[0023] [0023]FIG. 1 is a diagram illustrating how reporting criteria of a cell are obtained by its controlling radio network controller (prior art),
[0024] [0024]FIG. 2 is a diagram illustrating objects used by a radio network controller in determining reporting criteria of cells that it controls (prior art),
[0025] [0025]FIG. 3 is a diagram illustrating a Universal Mobile Telecommunications System (UMTS) terrestrial radio access network (UTRAN),
[0026] [0026]FIG. 4 is a diagram illustrating regions of coverage by the network,
[0027] [0027]FIG. 5 is a diagram illustrating some objects used by a radio network controller in determining reporting criteria of cells that it controls,
[0028] [0028]FIG. 6 is a diagram illustrating one option for configuring the objects shown in FIG. 5 so as to determine the reporting criteria of the cells,
[0029] [0029]FIG. 7 is a diagram illustrating another option for configuring the objects shown in FIG. 5 so as to determine the reporting criteria of the cells,
[0030] [0030]FIG. 8 is a diagram illustrating how reporting criteria usable in respect by one or some cells can be obtained, and
[0031] [0031]FIG. 9 is a diagram illustrating how reporting criteria are obtained for a cell under the control of another radio network controller.
DETAILED DESCRIPTION
[0032] In the described embodiment, the network is a code division multiple access (CDMA) system for mobile telecommunications, in particular a Universal Mobile Telecommunications System (UMTS) terrestrial access network (UTRAN). When a mobile user terminal is in a region in which soft-handover is possible, the signal from a mobile user terminal can be received by more than one cell of the network. Combining the signals from different cells provides soft-handover gain (i.e. the benefit of being able to select the strongest signal in the uplink (i.e. in the direction from a mobile to the base station).
[0033] For soft-handover to work, one important aspect is to have measurement reporting from the mobile user terminal (sometimes referred to as user equipment, UE). The measurement reporting from the mobile user terminal is controlled by the network by way of sending reporting criteria to the mobile user terminal. Reporting criteria of a cell are obtained by its controlling radio network controller for transmission to and use by a mobile user terminal. Different reporting criteria can be applied in each cell (i.e. reporting criteria may differ on a per cell basis). It is necessary that the correct reporting criteria are used to give up-to-date measurement reporting. The reporting criteria normally consists of event-triggered conditions. (Examples of event-triggered condition can be found in for example Third Generation Partnership Project (3GPP) Technical Specification 25.331 Section 14.1.2). The reporting criteria includes, for example, whether the signal strength from the cell is above a first threshold whereby the cell is to be included in the active set of cells having a radio connection to a mobile user terminal; or is below a second threshold whereby the cell is removed from the active set by taking down the radio connection. Another measurement criterion depends on hysteresis (i.e. the time for which the criteria must be met before that is reported).
[0034] For inter-frequency handover (i.e. from one set of frequency bands to another) and inter-radio access technology handover (i.e. from one radio access technology to another, e.g. from a UTRAN network to a General Packet Radio Service (GPRS)network), measurement reporting criteria are also needed by the mobile user terminal in order to make a measurement report to the UTRAN network.
[0035] The architecture of the UTRAN network is basically, as shown in FIG. 3. In the Figure only two radio network controllers 10 , three base stations 12 , nine cells 14 and one mobile user terminal 16 are shown for simplicity. Each base station 12 (Node B in UMTS terminology) of the network typically has three radio coverage areas (i.e. cells, also known as sectors) as the base station has three directional antennas angled at 120 degrees to each other. Radio network controllers (RNC) each control several base stations and hence a number of cells.
[0036] [0036]FIG. 3 shows three radio connections in a soft-handover scenario. Two of the radio connections 18 are to cells (cell 5 and cell 6 in FIG. 3) controlled via a base station (Node B) by a serving radio network controller (SRNC) 20 and the other radio connection 22 is to a cell (cell 7 ) controlled (via another base station) by another radio network controller, known as a drift radio network controller (DRNC) 24 . The mobile user terminal 16 is provided with the reporting criteria for one of Cell 5 , 6 or 7 shown in FIG. 1 dependent on which of those cells gives the strongest signal.
[0037] As shown in FIG. 3, each radio network controller (RNC) 10 , regardless of whether a serving radio network controller (SRNC) 20 or drift radio network controller (DRNC) 24 , controls an associated set of cells 14 via base stations 12 . Each radio network controller (RNC) 10 stores information, including the reporting criteria of the cells 14 that it controls. Within a radio network controller (RNC) 10 it is not necessary to store reporting criteria and possible other information of each cell as those criteria are likely to be the same.
[0038] Turning now to FIG. 4, each of geographical regions 1 , 2 , 3 , and 4 contain a set of cells (not shown in the Figure) controlled by a respective single radio network controller (not shown in the Figure). For region 1 , as the radio propagation environment is uniform across that region, the cells within that region have the same (i.e. common) reporting criteria. Similarly for region 2 , as the channel environment is uniform across that region, the cells within that region have the same reporting criteria. Similarly for region 3 , as the radio propagation environment is uniform across that region, the cells within that region have the same reporting criteria. However for region 4 , the radio propagation environment varies (due to the terrain being mountainous for example. Thus each of the cells within region 4 requires different reporting criteria.
[0039] Hierarchical Measurement Reporting Criteria
[0040] As generally most of the cells have the same measurement reporting criteria, it is wise to have the measurement reporting criteria on two-levels: one being on cell level (i.e. different for different cells) and the other being at a higher level. The higher level criteria can apply to a subset of the cells controlled by a radio network controller (RNC), all of the cells controlled by a radio network controller (RNC), or even the cells controlled by more than one radio network controller (RNC). The lower level (i.e. the cell level) is more tailored for a particular cell so when cell-specific measurement criteria exist, these take precedence. An illustration is provided in FIG. 5.
[0041] [0041]FIG. 5 illustrates an object-orientated query mechanism which occurs within the radio network controller (RNC) to determine the reporting criteria for a cell controlled by the radio network controller. The system object 26 requesting the information makes a reference to (in other words has a pointer to) another object, namely a cell object for the cell under consideration (be that cell object A 28 , cell object B 30 , or cell object C 32 . As is well known in the field of object-orientated design, an object is a database plus some computational intelligence with which to process data. In FIG. 5, cell object A and cell object C use the reporting criteria 34 which are kept as default in the system object 26 while cell object B uses its own cell-specific reporting criteria 36 which is part of cell object B.
[0042] The basic approach shown in FIG. 5 can be implemented in different ways as described immediately below.
[0043] First Option
[0044] As shown in FIG. 6, within a radio network controller (RNC), the set of reporting criteria is obtained for the system object using pointers 29 from cell objects. When reporting criteria 34 ′ for cell object A or cell object C is required by the system object 26 ′, the system object 26 ′ asks cell object A ( 28 ′) or cell object C ( 32 ′) for the reporting criteria 34 ′to be applied. Hence the number of objects for reporting criteria is small but the large number of queries from the system object remains.
[0045] (Incidentally as shown in the FIG. 6, when reporting criteria 36 ′ for cell object B is required, the system object 26 ′ asks cell object B ( 30 ′) for the reporting criteria 34 ′ to be applied. Cell object B ( 30 ′) has a pointer to the reporting criteria 36 ′)
[0046] Second Option
[0047] As shown in FIG. 7, reporting criteria for the system object 26 ″ is obtained using a pointer from the system object itself directly to the reporting criteria 34 ′ for cell A or cell C. Incidentally as shown in the FIG. 7, when reporting criteria 36 ″ for cell object B is required, the system object 26 ″ asks cell object B ( 30 ″) for the reporting criteria 34 ″ to be applied. Cell object B ( 30 ″) has a pointer 29 ′ to the reporting criteria 36 ″
[0048] This second option reduces both the number of objects as well as the number of inter-object queries whereas the first option only reduces the number of objects (compared to the prior art approach illustrated in FIG. 2 in which each cell has its associated reporting criteria stored in the radio network controller).
[0049] Extension to other Levels
[0050] This approach can be extended to multiple levels as shown in FIG. 8. As shown in FIG. 8, the cells in region 1 ′ can use cell specific reporting criteria, reporting criteria applicable across region 1 ′ only, or a standard reporting criteria for cells controlled by the radio network controller. For example with reference to FIG. 8, uses radio network controller (RNC) level reporting criteria, cell B′ uses cell specific reporting criteria, and cells C′ and D′ use region 1 ′ specific reporting criteria.
[0051] Sending Measurement Reporting Criteria as Part of Radio Connection Establishment
[0052] The measurement reporting criteria from cells connected to a drift radio network controller are sent whenever a radio connection is established. FIG. 9 shows in example case 1 the normal scenario of setting up radio connections including sending radio connection set up requests 38 , 38 ′ to the two drift radio network controllers 24 ′, 24 ″ (also denoted DRNC 1 , DRNC 2 in FIG. 9) and the responses 40 , 40 ′ from the two drift radio network controllers 24 ′, 24 ″, those responses containing the measurement reporting criteria for the cells (denoted cell # 1 , cell # 2 in FIG. 9) connected to the drift radio network controllers. If no measurement reporting criteria is in the response message 40 , 40 ′, the serving radio network controller (SRNC) 20 ′ uses its own default measurement reporting criteria rather than cell-specific measurement criteria.
[0053] Example case 2 in FIG. 9 shows the case when a radio connection between a mobile user terminal and a neighboring cell is already established (using radio connection set up request 42 and response 42 ′) under the control of the drift radio network controller ( 24 ′, DRNC 1 in FIG. 9) and later, a second radio connection with the mobile user terminal is requested 44 to be set up under the control of the same drift radio network controller ( 24 ′, DRNC 1 ) and with the same measurement reporting criteria as the first radio connection. In this case, the second radio link setup response 44 ′ from the drift radio network controller ( 24 ′, DRNC 1 ) does not include the measurement reporting criteria.
[0054] Explicit Message Requesting Reporting Criteria
[0055] In an alternative embodiment, rather than getting the measurement reporting criteria in reply to a radio link setup request, (i.e. instead of having the drift radio network controller respond with reporting criteria whenever a radio connection in being set up under the control of the drift radio network controller), the serving RNC requests the measurement reporting criteria from the drift radio network controller (DRNC) using an explicit message whenever it needs to.
[0056] For example, serving radio network controller can request the measurement reporting criteria for the strongest cell. In other words, the serving radio network controller requests the reporting criteria from the drift radio network controller only if the cell (to which the radio connection is to be set up) is the cell with least signal attenuation to and from the mobile user terminal (i.e. strongest cell) within the set of cells (the “active set”)in radio connection with the mobile user terminal.
[0057] This mechanism is particular suitable for inter-radio access technology and inter-frequency handovers. | A method is provided of providing to a mobile user terminal a set of measurement reporting criteria to be applied by the mobile user terminal in respect of a predetermined cell of a radio telecommunications network. The network comprises a plurality of cells and a controller. The method comprises the controller selecting the set of criteria from stored sets of criteria, one set of which is a default set for all cells under the control of the controller, and another set of which is a cell-specific set of criteria. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] NOT APPLICABLE
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention has been created without the sponsorship or funding of any federally sponsored research or development program.
FIELD OF THE INVENTION
[0003] This invention relates to the field of mass spectrometry. More particularly, it relates to the field of tandem mass spectrometry.
BACKGROUND OF THE INVENTION
[0004] In the field of tandem mass spectrometry, it is common to use different kinds of mass analyzers and mass filters in series to improve analytical performance of the combined system. However coupling between different mass analyzers is not always technically easy or even possible. The most common combinations of the mass analyzers are triple quadrupole instruments, where two linear quadrupole filters are connected by a collision cell positioned in-between. An efficient way to couple linear quadrupole, collision cell and a time of flight (TOF) analyzer is disclosed in EP1006559. Magnetic and electric sector analyzers are also commonly used in tandem. These instruments are typically expensive, free standing instruments. Several systems have been recently developed to couple an ion trap with a time of flight mass analyzer. For example, U.S. Pat. No. 5,569,917 describes a combination of an ion trap followed by time of flight mass analyzer. However, the resulting combination is characterized by substantially increased cost and the necessity to operate time of flight at very high energy to obtain reasonable accuracy and resolution of analysis readings.
[0005] In another tandem mass spectrometry system, the time of flight mass analyzer was coupled with a quadrupole collision cell followed by a second time of flight analyzer, see WO 0077823 and WO 0077822. In this configuration, it was possible to achieve fragmentation information for the molecule of interest using two time of flight mass analyzers. Like previous systems the final configuration is somewhat expensive and bulky.
[0006] In still another tandem mass spectrometry system, two linear quadrupoles were connected by a placing ion trap mass analyzer in-between (Kofel. P.; Peinhard, H.; Schlunegger, U.; Org. Mass Spectrum., 1991, 26, 463). This mass spectrometer system contained two precisionly machined quadrupoles. This results in a complex and expensive system with moderate performance, with the difficulty of coupling an ion beam from a quadrupole mass filter to an ion trap mass analyzer. These and other difficulties experienced with the prior art tandem mass spectrometry systems may be obviated by the present invention.
[0007] What is needed is an economical and efficient way to select ions of a specific mass range that can be injected into a mass analyzer from a continuous ion source to improve selectivity and sensitivity for the mass spectrometer system.
SUMMARY OF THE INVENTION
[0008] Apparatus for and method of delivering ions to a mass analyzer. The apparatus includes a time of flight ion guide, a pulsing device for receiving a continuous ion stream containing ions of different atomic mass and for delivering pulses of ions from the continuous stream of ions into the entrance end of the ion guide so that ions in each pulse reach the exit end of the ion guide in ascending order of their atomic mass, and a gating device at the exit end of the ion guide operating in timed sequence with the pulsing device for allowing only ions of a predetermined atomic mass in each pulse to pass through the gating device to the mass analyzer. The invention also includes a mass spectrometer that includes the apparatus for delivering ions described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated in the accompanying drawings, in which:
[0010] FIG. 1 is a diagrammatic view of a example of an ion delivery system of the present invention applied to an ion trap mass spectrometer;
[0011] FIG. 2 is an example of a timing diagram for the present invention;
[0012] FIG. 3 is an isometric view of a two part ion lens which serves as the ion gating device portion of the present invention;
[0013] FIGS. 4-7 are mass spectra obtained from an ion trap mass spectrometer, utilizing an ion delivery system of the present invention; and
[0014] FIG. 8 is an example of a timing diagram for the selection of two mass ranges of ions for injection into the mass spectrometer system.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring to FIG. 1 , an example is shown of a mass spectrometer system incorporating the present invention including of an ion source, generally indicated by the reference numeral 26 , a linear time of flight mass separator, generally indicated by the reference numeral 1 and a quadrupole ion trap mass analyzer, generally indicated by the reference numeral 6 . The time of flight mass separator 1 comprises a first or preliminary ion guide, generally indicated by the reference numeral 2 , a second ion guide, generally indicated by the reference numeral 4 , a gating device, generally indicated by the reference numeral 5 , and an ion trap entrance lens, generally indicated by the reference numeral 30 . A pulsing device, generally indicated by the reference numeral 11 , is located between ion guides 2 and 4 and defines an ion pulse region, generally indicated by the reference numeral 3 . The first ion guide 2 may be a radio frequency (RF) ion guide, or it may be any other type of ion guide, such as, by way of example and not limitation, a direct current (DC) ion guide, a stacked ring ion guide or an ion lens system. If it is an RF or a DC guide, it may comprise a multipole structure. Similarly, the second ion guide 4 may be any type of ion guide, with examples similar to those given for ion guide 2 . In some exemplary systems incorporating the invention, first ion guide 2 may be omitted.
[0016] The ion source 26 may be any ion source known in the art that can be used for generating ions from an analyte sample and delivering them to a mass spectrometer system. Examples include atmospheric pressure ionization (API) sources, such as electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) sources. The analyte sample may be in liquid or gas form, for example, and is introduced into the ion source 26 by means well known in the art. The ion source 26 communicates with an interface 9 that comprises functions of transmitting ions from the ion source 26 to the mass spectrometer system and, optionally, allowing a reduction of gas pressure from that of the ion source 26 to that of the mass spectrometer system. Interface 9 may be an orifice, a capillary, a tube, a passageway or any other such device for ion transport and, optionally, pressure reduction.
[0017] The exemplary mass spectrometer system comprises one or more vacuum chambers, for example chambers 15 , 16 and 25 shown in FIG. 1 , that may optionally be separately pumped by vacuum pumps (not shown). In FIG. 1 , an optional skimmer 14 is shown dividing chamber 15 and 16 , the first ion guide 2 is shown within chamber 16 , and second ion guide 4 is shown as located within chamber 25 . The quadrupole ion trap mass analyzer 6 comprises a quadrupole ion trap, generally indicated by the reference number 23 , and an ion detector 7 . The quadrupole ion trap comprises end cap electrodes 17 and 18 and a ring electrode 24 .
[0018] The various components of the mass spectrometer system shown in FIG. 1 , such as the interface 9 , skimmer 14 , ions guide 2 and 4 , pulsing device 11 , and lens 30 , gating device 5 and ion trap 23 are connected to conventional electrical power sources and controls in a manner well known in the art of mass spectrometers to produce the electrical potential, voltages, and timing described in the example of systems described in this application.
[0019] The power supplies for each of the electrical components of the exemplary mass spectrometer system of the present invention are shown diagrammatically in FIG. 1 . The power to interface 9 is indicated by block 54 . The power supply to skimmer 14 and first ion guide 2 are represented by blocks 55 and 56 , respectively. The power supply to lenses 10 and 20 are represented by block 57 . The power supply to the split lens 27 is represented by block 58 . Power supplies 57 and 58 are connected to a master clock represented by block 59 to insure that the lens 27 operates in timed sequence with the operation of the lenses 10 and 20 . The power supply, i.e. radio frequency generator, to the second ion guide 4 is represented by block 60 . The power supply to the quadrupole ion trap 28 is represented by block 61 .
[0020] According to the present example of the invention, a continuous beam of ions 8 from the interface 9 pass through the skimmer 14 and enter the first or preliminary ion guide 2 . The ions travel along a preliminary ion path through the ion guide 2 and accumulate in the ion pulse region 3 . After accumulation, ions are pulsed out into the second ion guide 4 , that serves as the free flight region for the time of flight mass separator 1 . All of the pulsed ions have substantially the same energy. Therefore, the flight time of ions through the second ion guide 4 depends only on their m/z. The gating device 5 at the exit of the second ion guide operates with a controlled time delay, synchronized with the ion pulse and stays open also for a predetermined period of time. This allows only ions having masses within a selected m/z range to enter the ion trap mass analyzer 23 .
[0021] A typical timing diagram for the control pulses is shown in FIG. 2 . Ions are typically stored in the ion pulse region during D 1 and P 2 time intervals, then ions are pulsed out of region 3 during P 1 time interval and the process continues in cycles. During the D 1 time interval, the pulsed out ions separate in their positions along the longitudinal axis of the second ion guide 4 according their m/z values, while the new portion of ions is accumulated in the ion pulse region 3 . The typical time for the pulses P 1 is 10 microseconds, while the whole cycle (P 1 +D 1 +P 2 ) is 100 microseconds, thus resulting in 10 kH z repetition rate.
[0022] In an example, the first ion guide 2 is an octapole ion guide 25 mm long with 3 mm inscribed diameter. The second ion guide 4 is 260 mm long with the same inscribed diameter as the first ion guide. Both ion guides 2 and 4 operated at 2.2 Mhz, 150 V peak-to-peak radio frequency voltage applied in the usual manner for an octapole RF ion guide. Pulsing device 11 comprises two lenses 10 and 20 . Lens 20 has a 3.5 mm ID aperture 22 . Lens 10 has an aperture 21 that is substantially larger than aperture 22 . The pressure in the pulse region 3 is in the range of about 10 to about 10 −1 mTorr, due to the neutral gas accompanying the ion beam 8 into first ion guide 2 . The presence of the neutral gas is useful for the efficient ion accumulation in the pulse region 3 . Several DC voltages are applied to the ion optical elements to produce continuous cycles of ion accumulation in the pulse region 3 . Ion guide 2 is maintained typically at 1.8V DC, lens 10 at 1V DC, lens 20 is pulsed from 30V DC during ion accumulation to 0V DC during ion pulse out (P 1 ), the second ion guide 4 is maintained at −21V.
[0023] The gating device 5 is a split lens, generally indicated by the reference numeral 27 , shown also in FIG. 3 . The split lens 27 is an electric lens comprising a first element 40 and a second element 50 . The lens 27 has an aperture 41 . A first portion 42 of the aperture 41 is located in the element 40 . A second portion 52 of the aperture 41 is located in the element 50 . Both lens elements 40 and 50 for the gating device 5 are maintained at the same potential of −5V during (P 2 ) pulse to provide ion transmission for the ions of selected mass range. During the rest of the time, the lens element 50 is switched to −100V to deflect the ion beam. The ion lens 30 serves as a refocusing element to direct the ion beam into the ion trap 23 and is maintained at −70V for the experiments. Refocusing can be accomplished by any number of ion lenses known in the art for example, an aperture lens, a system of aperture lenses, one or more einzle lenses, a dc quadrapole lens system, a cylinder lens or system thereof, or any combination of the above lenses.
[0024] Tests with the system of the present invention were performed on a modified Ion Trap MSD instrument from Agilent Technologies, wherein the standard ion optics in the third vacuum chamber were replaced with TOF ion optics as described in the above described example. The standard calibration mix sample from Agilent Technologies (part# G2431A) was introduced through a standard electrospray nebulizer. This sample has several ion species across the complete range of the mass analyzer; with m/z of 118, 322, 622, 922, 1522, and 2122 Da.
[0025] FIG. 4 shows a mass spectrum obtained with P 1 =10 microseconds, D 1 =19 microseconds and P 2 =15 microseconds. Only masses within the mass range from 70 to 250 are selectively injected into the ion trap with the main peak at mass 118 Da.
[0026] FIG. 5 shows the spectrum obtained at P 1 =10 microseconds, D 1 =30 microseconds and P 2 =15 microseconds. As expected, the increase in the delay time D 1 between pulses P 1 and P 2 shifts the transmitted mass range to the higher m/z values.
[0027] FIG. 6 shows a spectrum with maximum of the transmission window positioned around the m/z 1522 Da peak, which is obtained with P 1 =10 microseconds, D 1 =6 microseconds and P 2 =15 microseconds.
[0028] FIG. 7 shows the transmission window positioned around the m/z 2122 Da microseconds peak with P 1 =10 microseconds, D 1 =76 microseconds and P 2 =15 microseconds. All the spectra were obtained with total of 10 time of flight cycles with 100 microseconds duration time for each cycle. For the analytical applications, the optimum number of time of flight cycles injected into the ion trap can be calculated based on the previous scan information. Alternatively, a special short scan can be used to evaluate the number of cycles that are needed during the following main scan to target the same number of ions injected into an ion trap. This short scan can have a small fixed number of ions from time-of-flight cycles injected into an ion trap, with fast scanning of the trap analyzer to evaluate the intensity of the injected beam for the main scan. It is recognized, that it is also beneficial to synchronize the pulse P 1 with the phase of the main radio frequency voltage of the ion trap mass analyzer in a way that ions of interest arrive at the ion trap entrance at the most favorable phase for the injection, thus further improving sensitivity for the tandem system. It is also recognized that two or more mass ranges can be selected to transmit ions from within those ranges into an ion trap and to reject ions outside of the selected ranges.
[0029] FIG. 8 shows the timing diagram for the selection of two mass ranges for the injection into the ion trap. Ions are pulsed out from the storage region 3 during the pulse P 1 . during D 1 , a new portion of ions are accumulated in the storage region 3 , while pulsed out ions are separated in a second ion guide according to their m/z values. The gating device 5 opens twice. In the first opening, the ions in the first mass region first pass during the P 21 pulse. After time delay D 2 , gating device 5 opens a second time to pass ions for the second mass region during the time P 22 . This mode can be of particular benefit when rejection of a single matrix ion is desired.
[0030] Although examples of the invention are described, the invention is not limited to any particular implementation. For example, the radio frequency ion guide can be a quadrupole, hexapole or other multipole device, as well as a structure of rings or a multipole sliced into several segments as is well known in the art. The gating device can be of different geometry and design as well known in the prior art. The ion delivery system of the present invention can be used with different ionization techniques including electrospray, electron impact, etc. The ion delivery system of the present invention operates at relatively low energy and only allows ions within a predetermined mass range to enter the ion trap of quadrupole ion trap mass analyzer. This also may result in improved sensitivity, selectively and signal-to-noise ratio for the mass analyzer.
[0031] According to the present invention the time of flight mass separator can operate at unusually low accelerating energy (below several hundred volts), since ions are guided in free flight region by an ion guide (otherwise the ions would disperse). Low ion energy simplifies the design, and also results in small, portable instruments. Another advantage of the device may be high duty cycle (close to 100%), since ions can be accumulated in the ion pulse region for about the same period of time that it takes for the heavier mass of interest to reach the exit of the second ion guide. Also, since virtually no ions are lost during accumulation in the pulsed region, the ion transmission in the selected mass window may be close to 100%. Therefore, the tandem combination of a linear time of flight mass analyzer and an ion trap mass analyzer allows selecting a predetermined mass range to be injected into an ion trap without appreciable losses in the ion intensities. This results in filling the ion trap to capacity only with ions of interest within a specified mass range and rejecting the interfering matrix ions outside of the transmission window, thus improving sensitivity, selectivity and signal to noise ratio for the ion trap mass analyzer. | Apparatus for delivering ions to a mass analyzer. The apparatus includes a time of flight ion guide, a pulsing device for receiving a continuous ion stream containing ions of different atomic mass and for delivering pulses of ions to the ion guide wherein ions in each of the pulses of ions exit the ion guide in ascending order of their atomic mass, and a gating device at the exit end of the ion guide for allowing ions of a predetermined atomic mass to pass to the mass analyzer. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to abdominal wall reinforcement devices, and in particular devices used for the treatment of inguinal hernias by either an anterior or laparoscopic route.
[0003] 2. Description of the Related Art
[0004] Providing a permanent mechanical support for the repair of abdominal wall hernias is well known in the art. Various implants and surgical techniques have been developed to assist surgeons during reconstructive procedures to improve the outcome of such procedures, both in terms of its effectiveness and tolerance by the patient. It is known, for example, that reinforcement of the operative area by a mechanical implant is improved when the implant quickly integrates in the tissue. As disclosed in U.S. Pat. No. 6,596,002 (assigned to Sofradim), to achieve intimate and early integration of the implant without formation of a peripheral fibrous shell, the macroporosities of the implant must be as widely open as possible to the outside and the elasticity of the reinforcement must allow it to follow the physiological deformations of the wall onto which the device is placed. The suitability of such a device is related to the mechanical resistance of the textile material used to form the implant. It is reported that such resistance must be greater than 10 decanewtons using the standardized IS05081 test. Such devices should prevent hernia recurrence through the pores of the tissue, which must be a maximum of 7 to 10 millimeters in diameter.
[0005] The invention disclosed in U.S. Pat. No. 6,596,002, involves a knitted mesh useful for the treatment of inguinal hernias by the anterior access route, which is placed in a premuscular location. The knitted mesh is characterized as affording the practitioner with an implant device that is easy to use, quickly securable in place, and that effectively repairs abdominal wall deficiencies. The knitted mesh includes a reinforcement piece and a flap piece connected to the reinforcement piece. The reinforcement piece is cut from an open-worked prosthetic knit web. The web is made of multifilament yarns. The reinforcement piece includes a radial slit and annular cut-out region approximately in the center of the reinforcement piece that allows the surgeon to place the piece around the spermatic cord. According to the patent, the reinforcement piece has the general shape of an ellipse, and it satisfies the requirements mentioned above. In particular, the shape allows the surgeon to cover all the potential parietal weakness. The device is described as being easy to put into place.
[0006] The aforementioned flap piece is made such that it may be folded over the slit on the reinforcement piece to close it. The flap is described as having a “gripping means” integral with the flap itself, or attached to it, for fastening or joining the flap piece to the knitted structure of the reinforcement piece. In one embodiment, the flap is described as having spike naps projecting from its face. The spiked naps are formed by a monofilament yarn and have a length allowing them to penetrate into and attach themselves to the knitted structure of the reinforcement piece without protruding from the latter. That is, on one end, the spiked naps are embedded into the knit web to secure them, and on the other end project above the surface of the flap piece, generally extending above the plane of the flap piece in a perpendicular direction. Depending on the particular applications for the device, the spike naps are made of a biocompatible polymer or of bioabsorbable material, such as polylactic acid (PLA). In use, the flap is folded over the reinforcement piece such that the spiked naps engage in and between the multifilament yarns of the knit of the reinforcement piece, similar to a hook and loop fastener. This ensures that the flap piece is locked in position, securely closing the slit and holding the spermatic cord in position. The spiked naps are not permanent, however. The flap piece may be unfastened and repositioned, if necessary.
[0007] The density of the spiked naps is reportedly determined as a function of the prosthetic knit being used, but is reportedly best in the range of between 50 and 90 naps per cm 2 . The length of the naps, measured from the base projecting from the attachment sheet to the top of the spike, will depend on the thickness of the prosthetic knit forming the reinforcement piece, but is reportedly best in the range between 1 and 2 millimeters.
[0008] In the aforementioned patent, the reinforcement piece is described as having a grip or gripping means, which is integral with the knit or attached to it, and is used for fastening or joining The same spiked naps described above may be used on one face of the reinforcement piece, just as they are used on the flap piece. The grip/gripping means devices project from one and/or the other of the faces of the knit, and are used to fasten or join the reinforcement piece to the tissues the device is place in contact with. The knit from which the reinforcement piece is made is described as a “flat knit” type or one having two porous layers connected by connecting yarns. The weave of the knit forms run-proof transverse channels opening out from the two porous layers.
[0009] A commercial embodiment of the knitted mesh device called ProGrip™ is available from Covidien (Massachusetts). Its use is described in Philippe Chastan, M.D., “Tension-Free Open Inguinal Hernia Repair Using an Innovative Self Gripping Semi-Resorbable Mesh,” published in the Journal of Minimal Access Surgery, 2006 (see pp 139-43 describing results based on a published study of the Parietene™ (polypropylene) version of the ProGrip™). In its literature, Covidien states that the biocompatible monofilament knit making up the knitted mesh is made from non-resorbable polyethylene teraphthalate (PET), and the spike naps are made from a resorbable poly lactic acid (PLA). The monofilament knit is hydrophilic, so it works with the body's natural systems to improve tissue integration while reducing foreign material response. The entire mesh with the spike naps reportedly provides “immediate fixation” to the underlying tissue. The knit material is substantially stronger than using fibrin glue, and is equivalent to incorporation by hernia stapler fixation at five days after placement. Compared to suture fixation, the device is 100% stronger at four weeks. The literature also notes that the device can be positioned and placed in less than 60 seconds, and unlike standard open repair of parietal deficiencies, the device does not require additional fixation methods. The device has a reported density of 73.0 g/m 2 before resorption of the spiked naps, and a reported density of 38.0 g/m 2 after resorption (a change of 53 g/m 2 or 48-percent).
[0010] Despite the features and advantages of the invention described above, experience has shown that the spike naps may adhere too quickly for some applications, i.e., “immediate fixation” or adherence in less than 60 seconds. Removing the device (so it can be repositioned) is difficult after attachment, and it can be traumatic to the underlying tissue. Often, repositioning cannot be done, so a new device is requires, at relatively substantial expense to the patient or practitioner. Also, the device is expected to attach quickly to intra-abdominal tissues (e.g., smooth tissues such as bowel), and so the device is not useful for intra-abdominal implantation using, for example, laparoscopy instruments to place the device interiorly of, for example, an abddominal wall hernia. Accordingly, there exists a need for such a device.
[0011] It is well known in the medical arts to apply a measured amount of a spreadable “gel” to form a temporary layer, which may then provide the benefit of protecting, at least temporarily, another layer, material, or object, or to reduce the friction between two surfaces separated by the gel layer. Such a gel, if applied to the spiked naps of the aforementioned product, would reduce the gripping ability of the spiked naps and allow the practitioner to place and then replace the knitted mesh device before the spiked naps begin to adhere to the parietal tissues. However, if the gel has a high viscosity, the ability of the spiked naps to be reabsorbed by the underlying tissue may be greatly reduced, causing the knitted mesh to be too loose and require additional sutures. Also, low viscous gels are unsuitable from a manufacturing perspective, because they are difficult to apply to a mesh, and would require special or different packaging materials compared to a knitted mesh without a gel layer. Further, many gels may be easily disturbed by the practitioner's fingers and/or instruments used by the practitioner, thereby reducing or eliminating their effectiveness.
[0012] It is also well known in the medical arts to use adhesives to attached a device to a patient or substrate. An adhesive layer applies to the knitted mesh and/or spiked naps of the aforementioned device would immediately cause fixation, making it more difficult to remove or reposition. Also, unlike the spiked naps of the aforementioned knitted mesh device, an adhesive is generally not reabsorbed (at least not immediately), and so it can form (at least temporarily) a generally impenetrable layer between the device and the underlying tissue, which may not be desirable in certain applications.
[0013] It is also known in the medical arts to use a removable, protective film or layer over another layer. Thus, a film could be used over an adhesive layer on a device that prevents the adhesive from sticking until the device is used. Such protective films are relatively inexpensive to make from various inert, compatible, and stable polymeric materials. In use, the practitioner simply removes and discards the film, then positions the device and permanently places it using the underlying adhesive to hold the device in place. Adding a film to an adhesive layer may be feasible, but it may not be suitable for adding directly to the knitted mesh device described above without at least some adhesive between the file and underlying PET knit and PLA spiked naps extending from the knit. If the film attaches to the spiked naps, it may not be cleanly removable without destroying some of the spiked naps, thereby reducing the effectiveness of those devices for their intended purpose. Also, removing the film intra-abdominally presents all sorts of challenges to the practitioner and is, practically speaking, not feasible (i.e., the film would have to be removed exteriorly of the patient).
[0014] Accordingly, there exists a need for a material that reduces the time before the spiked naps of the aforementioned invention begins to adhere and reabsorb in the tissue so that it can be removed and repositioned quickly, is suitable for manual placement by a practitioner's fingers or using a laparoscopy instrument, and is relatively inexpensive to manufacture.
SUMMARY AND OBJECTS OF THE INVENTION
[0015] Accordingly, it is a principal object of the present invention to provide a reinforcing device for effective parietal hernia repair and other reconstructive tissue repairs that can be positioned by a practitioner using an anterior route as well and a laparoscopic route.
[0016] It is also an object of the invention to provide a reinforcing device that is suitable for placement in an intra-abdominal or intra-pelvic location using a laparoscopic device that does not require conventional sutures or staples.
[0017] It is still another object of the invention to provide a reinforcing device made from a knitted mesh having spiked naps in which at least a portion or all of the knitted mesh and spiked naps on one of the faces of the device are covered with a layer that is dissolvable in a rate-controlling manner.
[0018] It is another object of the invention to provide a dissolvable material that may be coated on a monofilament strand of PET and/or a spiked nap of PLA to a pre-determined thickness and that dissolves at a pre-determine rate from the outer contact surface exposed to various solvents.
[0019] It is still another object of the invention to include a formulation for a dissolvable matrix having one or more of a biodegradable component, an antibacterial component, an excipient, a therapeutic drug, a plasticizer, and a binder component.
[0020] It is another object of the invention to provide a device that is relatively easy for a practitioner to use.
[0021] It is still another object of the invention to provide a device that is relatively easy to manufacture.
[0022] Briefly described, the above and other objects and advantages of the present invention are accomplished, as embodied and fully described herein, by a reinforcement device for reinforcing tissues having one or more structural deficiencies, such as parietal tissues. The device includes a longitudinally-extending reinforcing layer for treating the structural deficiency, the layer having an upper and a lower face, a flap portion, a slit portion, and a cut-out portion; a plurality of spiked naps distributed across one or both of the faces and the flap portion and projecting therefrom for adhering to the tissue; and a first dissolvable matrix layer covering at least a portion of the reinforcing layer and a portion of the plurality of spiked naps, the matrix layer increasing the time before the spiked naps substantially adhere to the tissue.
[0023] The above and other objects and advantages of the present invention are also accomplished, as embodied and fully described herein, by a method for reinforcing tissues having one or more structural deficiencies, the treatment method including the steps of providing a reinforcement device as described above, and holding the reinforcement device at the tissue until at least a portion of the dissolvable matrix layer dissolves, allowing the device to adhere to the tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a perspective schematic drawing of a reinforcing device according to the prior art;
[0025] FIG. 2 is a plan view of the reinforcing device of FIG. 1 ;
[0026] FIG. 3 is a partial cross-sectional elevation view of the reinforcing device according to one aspect of the present invention;
[0027] FIG. 4 is a partial cross-sectional elevation view of the reinforcing device according to another aspect of the present invention;
[0028] FIG. 5 is a plan view of the reinforcing device of FIG. 1 according to another aspect of the present invention;
[0029] FIG. 6 is a partial cross-sectional view of section A-A of FIG. 5 showing the partial coverage of the reinforcing device with a dissolvable matrix layer and a bioadhesive layer;
[0030] FIG. 7 shows the change in the thickness, d (millimeters), of the dissolvable matrix layer over time; and
[0031] FIG. 8 is a partial cross-sectional view of a single spiked nap according to one aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Several preferred embodiments of the present invention are described for illustrative purposes, it being understood that the invention may be embodied in other forms not specifically shown in the drawings. The figures will be described with respect to the structure and functions that achieve one or more of the objects of the invention and/or receive the benefits derived from the advantages of the invention as set forth above.
[0033] Turning first to FIG. 1 , shown therein is a perspective schematic drawing of a reinforcing device 102 according to the present invention. The reinforcing device 102 is made substantially in accordance with the device disclosed in U.S. Pat. No. 6,596,002, i.e., a knit which satisfies the requirements of the knits mentioned in the background section of the present description. Thus, the knit may be three-dimensional and open-worked, with two porous faces connected by connecting yarns.
[0034] The reinforcing device 102 has an upper face 104 and a lower face 106 and is formed with a cut-out 108 approximately in the center of the reinforcing device 102 as shown. The cut-out 108 has a diameter of about 3 to 7 millimeters.
[0035] The knit may be made of a monofilament yarn such as polyester, including PET or similar materials. The knit is flexible, as depicted in FIG. 1 , but it could also be made semi-rigid by coating or reacting the yarn with a suitable polymer, plasticizer, or other material.
[0036] Turning now to FIG. 2 , shown therein is a plan view of the reinforcing device 102 of the previous figure. As further disclosed in the aforementioned patent, which is incorporated herein by reference, the reinforcing device 102 is generally in the shape of an ellipse. This ellipse includes a large radius of curvature on the upper and lower edges, and a smaller radius of curvature on the left and right edges, respectively. The reinforcing device 102 may be made to other shapes and sizes as needed. It is preferable that the specific edge shape correspond to one or more edges formed by the practitioner in a patient undergoing a procedure to place the reinforcing device 102 . This will allow the device to be positioned in the best anatomical position in which it will remain after the procedure.
[0037] The reinforcing device 102 includes, about halfway along the length of the upper edge and extending from the cut-out 108 to the upper edge, an end portion 206 , which is covered by a flap portion 202 . The combination of the flap portion 202 and the end portion 206 forms a slit or opening that is generally perpendicular to the upper edge and parallel to the end portion 206 .
[0038] Near one edge of the reinforcing device 102 is a cord 204 made from a biocompatible yarn material that is generally stronger than the rest of the material of the reinforcing device 102 , and provides a suitable anchor for fixing a conventional suture or staple, if needed. Additional cords 104 could also be added to the reinforcing device 102 .
[0039] The flap portion 202 has may have the shape shown, i.e., rectilinear polygon, or the shape of a sector of a circular annulus, or some other suitable shape. It may also be a separate piece that is attached to the reinforcing device 102 at one of its linear or arcuate edges. The flap portion 202 extends over a portion of the upper face 104 of the reinforcing device 102 such that when it is joined to the reinforcing device 102 the lower edge is lined up with an edge of the cut-out 108 .
[0040] As noted in the referenced patent, the flap portion 202 is composed of an open-worked, run-proof knit made, for example, of multifilament synthetic yarns of polyester. In the case where the flap portion 202 is a separate piece, it may be joined or attached to the reinforcing device 102 by a longitudinal stitch or seam that runs parallel to one of the edge of the end portion 206 .
[0041] The knit used to make the flap portion 202 includes one or more monofilament yarns forming spiked naps projecting from the flap portion 202 or the lower face 106 of the reinforcing device 102 (and/or also projecting from the upper face 104 ). Depending on the specific medical application, the yarn for these spiked naps may be made of a biocompatible polymer. Suitable polymers include, but are not limited to, polypropylene, or a bioabsorbable material. The bioabsorbable material may include, but is not limited to, polymers of p-dioxanone, polyglycolides, polyorthoesters, polymers of trimethylene carbonate, stereocopolymers of L-lactic acid and D-lactic acid, homopolymers of L-lactic acid, copolymers of lactic acid and a compatible comonomer, such as derivatives of alpha-hydroxy acids.
[0042] Turning now to FIG. 3 , shown therein is a partial cross-sectional elevation view of the reinforcing device 102 according to one aspect of the present invention. Shown therein are several spiked naps 304 , similar to those described above in connection with the flap portion 202 , projecting from the lower face 106 of the reinforcing device 102 . Each of the spiked naps 304 has a length sufficient to penetrate into the knit of the reinforcing device 102 (i.e., between the filaments of the yarns of the knitted structure of the reinforcing device 102 ). If the knit making up the reinforcing device 102 has a thickness of between 1.5 and 2.2 millimeters, as taught in the referenced patent, the length of the spiked naps 304 measured from their base, projecting from the lower face 106 to the summit of the spike could be between 1 and 2 millimeters, as also taught in the referenced patent. The spiked naps 304 do not have to be linear, and in fact may all have arcuate shaped elongated members terminating with an excess of the PLA material generally in the shape of a flattened ball at the distal end of the spiked naps 304 . The terminating end of the spiked naps 304 may also have other shapes, including, but not limited to, a tapered point or J-hook shape.
[0043] The density of the spiked naps 304 depends on several factors, but is based on the degree of adhesion required or desired for a particular application. Between 50 and 90 spiked naps 304 per square centimeter of the reinforcing device 102 is disclosed in the referenced patent and is suitable for most parietal reconstruction done from an anterior route. A lower or higher density may be suitable for other types of tissue and procedures.
[0044] Covering substantially all of the spiked naps 304 is a dissolvable matrix layer 302 shown in the figure as a thin layer having approximately the same thickness as the reinforcing device 102 , i.e., about 1.5 to 2.2 millimeters, though other thicknesses may be used. The dissolvable matrix layer 302 allows the reinforcing device 102 to float as it is being positioned over an area of tissue so that the spiked naps 304 do not immediately adhere to the underlying tissue. As the dissolvable matrix layer 302 dissolves, more of the spiked naps 304 are exposed allowing them to contact the tissue and begin to “adhere” by physical and/or chemical means. The dissolvable matrix layer 302 may extend across the entire lower face 106 (and/or the upper face 104 ) of the reinforcing device 102 , or only a portion of the lower face 106 (or upper face 104 ).
[0045] The dissolvable matrix layer 302 may include one or more of a biodegradable component, an antibacterial component, an excipient, a therapeutic drug, a plasticizer, and a binder component. Other ingredients may also be included.
[0046] A variety of polymers are available for the biodegradable component. Suitable polyers include, but are not limited to, methyl cellulose (MC), hydoxy propyl methyl cellulose (HPMC) (commercially: hypromellose), hydroxyl propyl cellulose (HPC), starch and modified starch, Pullulan, Pectin, Gelatin, and carboxy methyl cellulose (CMC). The polymer should account for about 45-percent to 85-percent w/w of the total weight of the dissolvable matrix layer 302 . The polymers identified above may be used alone or in combination to obtain the desired rate of mass transfer from the layer to the surrounding. The polymers provide strength and resist damage while handling or during transportation in conventional packaging materials. The strength depends on the type of the polymer(s) and their relative amounts in the dissolvable matrix layer 302 . The polymers are non-toxic, non-irritating, and lack leachable impurities. They have good wetting and spreadability properties, making them relatively easy to use in various unit chemical operations such as spray coating, fluidized reactors, pumping, etc. When in use (i.e., in a room temperature aqueous environment), they exhibit gel-like properties since most of the polymers are hydrophilic, and so they exhibit generally low peel strengths making them relatively easy to “float” over a substrate. In solid form, they exhibit good shear and tensile strengths and therefore resist damage from medical instruments. Methyl cellulose in particular can be used as a mild glue which can be washed away with water.
[0047] An antibacterial component may optionally be included in the dissolvable matrix layer 302 . A suitable non-toxic antibacterial agent includes, but is not limited to, silver ion powder (silver ions in an inert crystalline material). The antibacterial component should account for about 0 to about 5% w/w of the dissolvable matrix layer 302 , though higher percentages may be used. The antibacterial component in the dissolvable matrix layer 302 provides a germicidal effect that kills microbial organisms.
[0048] A therapeutic drug component may optionally be included in the dissolvable matrix layer 302 . The amount of such component may be determined based on the desired dosage, i.e., a mass of drug to a body mass ratio. The therapeutic drug component may be layered deep within the dissolvable matrix layer 302 to reduce loss after the reinforcing device 102 is placed in its final position and is washed (with a saline or water lavage), which can wash away the drug component. It may also be uniformly distributed within the dissolvable matrix layer 302 . The drug component can be added to the dissolvable matrix layer 302 as a milled, micronized, nanocrystal, or macro particle, depending upon the release profile desired.
[0049] A plasticizer may optionally be included in the dissolvable matrix layer 302 . Suitable plasticizers include glycerol, propylene glycol, low molecular weight polyethylene glycols, phthalate derivatives like dimethyl, diethyl and dibutyl phthalate, citrate derivatives such as tributyl, triethyl, acetyl citrate, triacetin and castor oil are some of the commonly used plasticizers used in dissolvable matrices like oral dissolvable strips. The plasticizers account for about 0 to about 20-percent w/w of the dry polymer weight, though a higher percentage may be used. The plasticizers improve the handling properties of the polymer and provide flexibility and reduce the brittleness of the dissolvable matrix layer 302 . Other advantages of plasticizers for use in dissolvable layers are discussed in Dixit et al., “Oral Strip Technology: Overview and Future Potential,” J. Controlled Release, 139: 94-107 (2009), the content of which is incorporated herein in its entirety.
[0050] An optional binder may also be included in the dissolvable matrix layer 302 . Suitable non-toxic binders are well known in the controlled release arts. The amount of binder will depend upon the desired rate of dissolution.
[0051] Turning now to FIG. 4 , shown therein is a partial cross-sectional elevation view of the reinforcing device 102 according to another aspect of the present invention. In the embodiment shown, a bioadhesive layer 402 may added between the knitted mesh of the reinforcing device 102 and the dissolvable matrix layer 302 such that when the dissolvable matrix layer 302 is removed, the bioadhesive layer is exposed and attaches or adheres to the underlying tissue. The bioadhesive layer 402 may have a variable thickness across the width of the reinforcing device 102 , and in another embodiment, only a portion of the knitted mesh is layered with the bioadhesive layer 402 . As shown in the figure, it has a thickness of about half or two-thirds of the thickness of the dissolvable matrix layer 302 , but the actual layer can be determined based on the specific application in which the reinforcing device 102 is used. The bioadhesive layer 402 is a natural polymeric materials that act as an adhesive, and may be dissolvable or resistant to dissolving (fixed thickness), and, as noted above, is used to supplement the adhesive function of the spiked naps 304 of the reinforcing device 102 . Suitable bioadhesives include gelatin, starch, modified starch, certain proteins, carbohydrates, glycoproteins, and mucopolysaccharides, and hydrogels, which can simulate natural tissue.
[0052] One of ordinary skill in the art will appreciate that other layers, or combinations of layers, and their position on the reinforcing device 102 , may be used for a particular application. For example, in FIG. 5 the dissolvable matrix layer 302 is shown applied to discrete locations on the reinforcing device 102 . Two of the locations are the left and right ends of the device, and the other location is concentric with the cut-out 108 . FIG. 6 is a partial cross-sectional view of section A-A ( FIG. 5 ), showing the partial coverage of the reinforcing device 102 with the dissolvable matrix layer 302 , and a bioadhesive layer 402 , which may be slowly or rapidly dissolvable. The dissolvable matrix layer 302 could be interchanged with the bioadhesive layer 402 in the embodiment shown, such that the dissolvable matrix layer 302 covers the bioadhesive layer 402 .
[0053] The dissolvable matrix layer 302 is dissolvable according to a pre-determined, controlled rate, which may be adjusted by using different ingredients or different concentrations of the same ingredients, or by using different solvents or combinations of solvents. Well known mass transfer principles may be used to describe the rate at which the layer dissolves (i.e., convective and diffusive degradation at the solid-liquid interface). FIG. 7 shows the change in the thickness, d (millimeters), of the dissolvable matrix layer 302 over time. Each of the lines shown has a different first- or higher-order dissolution rate over time. Line 702 , for example, represents a constant or first-order mass transfer rate at the surface of the dissolvable matrix layer 302 (transfer of solid to a surrounding convective fluid layer at the surface, i.e., the fluid provided by the practitioner as a water lavage when the device is positioned, and/or provided by natural bodily fluids at the site of the reinforcing device 102 ). Line 704 includes two different rates, 704 a and 704 b, each with a different rate of mass transfer. Line 706 represents a variable rate of mass transfer, which is rapid initially. Line 708 represents a low rate of mass transfer, whereby the thickness, d, changes slowly over time. Once the dissolvable matrix layer 304 is reduced by about 50-percent, most of the terminal ends of the spiked naps 304 will be exposed.
[0054] FIG. 8 is a partial cross-sectional view of a single spiked nap 304 having an elongated member 804 and terminating end 802 . The spiked nap 304 is shown coated with the dissolvable matrix layer 302 having a thickness, d (millimeters). Since the spiked nap 304 thus coated with the dissolvable matrix layer 302 may extend farther into a bulk fluid (e.g., solvent, such as water), the rate at which the thickness, d, changes over time may be greater than the layer 302 covering the knit of the reinforcing device 102 because of the increased prominence of convective mass transfer compared to diffusive mass transfer closer to the surface of the reinforcing device 102 .
[0055] In use, the reinforcing device 102 with the dissolvable matrix layer 302 is removed from its packaging material. In the case where a thin film covers the dissolvable matrix layer 302 , it is removed by the practitioner prior to use. In a conventional procedure to treat an inguinal hernia, the device is positioned in the anterior inguinal region of a patient and then the area is wetted with a water lavage (or some other solvent is used), which maintains a constant moisture source and helps dissolve the dissolvable matrix layer 302 . Dissolution occurs from both sides of the dissolvable matrix layer 302 . The anterior surface closest to the knitted mesh of the reinforcing device 102 is dissolved by the solvent as it penetrates the mess. The opposite surface is dissolved by the solvent as it penetrates from the sides of the reinforcing device 102 , between the space between the dissolvable matrix layer 302 and the underlying tissue, and by bodily fluids present at the site.
[0056] Depending on the thickness of the dissolvable matrix layer 302 or its composition, the spiked naps 304 will begin to be exposed and contact the underlying tissue, at which time they will begin to adhere to the tissue. Without the dissolvable matrix layer 302 , the reinforcing device 102 attaches almost immediately, but at least within about 30 seconds. Thus, the time until substantial attachment or adherence is in the range of about 0 to 30 seconds, which is increased with the dissolvable matrix layer 302 , such that substantial attachment occurs in a range from about 30 seconds to several minutes, depending, again, on the thickness and composition of the dissolvable matrix layer, and the amount and flow rate of the solvent.
[0057] Substantial attachment or adherence is measured in terms of peel strength, i.e., the force, measure in pounds or Newtons per area, required to remove the reinforcing device 102 after its placement on tissue after a pre-determined time period. This parameter is measurable; for example, the peel strength of two objects (one flexible, one rigid) joined together is the average load per unit width of bond line required to part the bonded materials from each other where the angle of separation is 180 degrees and separation rate is 6 in/min (ASTM D-903).
[0058] Preferably, the “float” period (i.e., the period before substantial adhesion) according to the present invention is from about 1 to 2 minutes at a peel strength of about 1 to about 3 N/cm, but a much lower peel strength may be desired. That is, when wetted, the dissolvable matrix layer 302 may form a gel that reduces the ability of the spiked naps 304 to adhere and become resorbable. This provides the practitioner sufficient time to assess the initial placement of the reinforcing device 102 and reposition the device as needed before adhesion begins. A faster adhesion would create a higher peel strength and would likely cause trauma to the underlying tissue and damage the reinforcing device 102 if attempts to remove it at that point were to occur.
[0059] Although certain presently preferred embodiments of the disclosed invention have been specifically described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the various embodiments shown and described herein may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law. | A reinforcement device for reinforcing tissues having one or more structural deficiencies includes a longitudinally-extending reinforcing layer for treating the structural deficiency, a plurality of spiked naps distributed across the reinforcing layer and projecting therefrom for adhering to the tissue, and a dissolvable matrix layer covering at least a portion of the reinforcing layer and a portion of the plurality of spiked naps. The matrix layer increases the time before the spiked naps substantially adhere to the tissue, thereby allowing the practitioner additional time to position the reinforcement device. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a process and a device for cooling the internal wall of a pipe made of plastics material during its extrusion.
2. Description of the Prior Art:
Modern manufacture of pipes made of plastics material by extrusion demands high-output extruders. Nevertheless, in order to produce large quantities of high quality pipes it is essential that the pipes are cooled during their extrusion in the most intensive and effective manner possible.
Conventional cooling using a water jet on the external surface is no longer suitable, given that the cooling is limited by the length of the cooling distance. The heat to be dissipated also depends on the thickness of the pipe wall and on the extrusion speed.
A solution has therefore been sought based on cooling via the inside of the pipe. Proposals based on the use of counter-current air or water or based on indirect cooling give results which are less than satisfactory.
Internal cooling by the dispersion of water has proved to be more promising. For this purpose small water droplets are sprayed in the form of a mist onto the internal wall of the pipe. From the heat transfer point of view the spraying of droplets represents a good solution, given that the quantity of heat necessary for the evaporation of water (latent heat) and therefore the heat removed from the pipe to be cooled, is about five times the quantity of heat which is removed by the water in a convective process.
Various modifications of this type of cooling are described in German Patent Applications DE-A 2455779, DE-A 3241005 and DE-A 3414029. According to these modifications, the cooling agent is sprayed in the form of droplets via a fixed device comprising a central orifice or a plurality of orifices distributed around the circumference. The device is disposed fixed, and is fixed in relation to the tube which travels axially.
It has been found that this cooling system comprises disadvantages and shortcomings.
In practice an important phenomenon which affects the cooling of pipes stems from the thermal conduction of the constituent material. The coefficient of thermal conduction of plastic materials is low. It follows from this that heat located at the surface or near the surface will be easily removed, but heat located at some depth in the pipes requires a period of time in order to reach the surface. Spraying droplets as proposed in the prior art only enables heat to be removed from the surface of the pipe.
Moreover, if a film of water is atomised onto the hot wall of the extruded pipe, part of the water is evaporated but the major part of the dispersed water runs from the pipe wall towards the bottom and converges in this region. The water then only contributes to the internal cooling of the pipe in this region. The cooling of the pipe is asymmetric. Furthermore, it has been noted that water droplets dispersed on a pipe made of plastic material preserve their form, given that the wetting between the water and the plastic material is poor, particularly when high density polyethylene is used. This phenomenon also impairs the efficacy of cooling with the aid of dispersed droplets.
SUMMARY OF THE INVENTION
The object of the present invention is to remedy these disadvantages and to provide a process and a device which enable improved cooling of the internal wall of an extruded pipe to be effected.
According to the invention a cooling agent is dispersed on the surface of the internal wall of the pipe in a plurality of successive iterations or cycles at given time intervals.
The element of time is thus caused to act in the cooling procedure. The heat inside the pipe wall has time to reach the surface after the heat near the surface has been removed. By spraying the same surface several times in succession, the disadvantages resulting from the prior art are overcome.
According to one advantageous process and device, the cooling agent is dispersed by means of a device placed inside the extruded pipe which is displaced in a reciprocating axial movement, i.e. in an oscillating movement.
According to a preferred embodiment, the cooling agent is dispersed in accordance with a rotating movement.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail below by way of example only, with the aid of an example of an embodiment and with reference to the accompanying Figures, where:
FIG. 1 is a schematic longitudinal section through an embodiment of the invention;
FIG. 2 is a section along the line X--X of FIG. 1;
FIG. 3 is a schematic section through a rotating dispersion injector.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, this illustrates a pipe extrusion injection head 1 having a chuck 2 and a support 3. The chuck 2 has a central bore through which a coolant dispersion tube 4 is introduced. This tube, therefore has one end situated inside the extruded plastic pipe 5. The central bore comprises a front sliding bush or bushing 6 and a rear sliding bush or bushing 7 which can guide the dispersion tube 4 with low friction during the oscillating movements of the latter. The sealing of the central bore around the tube 4 does not have to be perfect; it only has to prevent the propellant air used for dispersing the cooling agent from flowing back towards the rear. A labyrinth seal (not shown) installed in the rear sliding bush 7 may, therefore suffice.
The oscillating movement of the dispersion tube 4 may be produced in various ways. According to the example, a pneumatic piston 8 acting in both directions and provided with a rod 9 travels in a cylinder 10 comprising an air inlet 11 at both ends.
The piston rod 9 carries a pinion 12 which rotates between a fixed rack 13 and a displaceable rack 14 driven by the piston 8 and extending axially to the rear end 15 of the tube 4 and integral with the latter. The speed of the piston is preferably adjustable so that the displacement to the left (in the drawing), which causes a displacement of the tube 4 inside the extruded pipe 5 in the direction of cooling of the pipe (active phase), can be adjusted.
The rate of displacement of the tube 4 determines the number of oscillations and, therefore, the efficiency of cooling of the pipe.
The travel of the piston 8 in the opposite direction (to the right in the drawing), which causes a displacement of the tube 4 inside the extruded pipe in the direction of the injection head 1 (inactive phase), can be effected very rapidly. The speed of displacement of the tube 4 can be adjusted by various means; a simple solution is to equip the air inlets 11 with sized constrictions.
The speed of displacement of the tube during the active phase can thus be adjusted in relation to the wall thickness of the extruded pipe, the type of plastic material used and the extrusion output. These are the parameters which broadly define the quantity of heat to be removed. The travel of the tube 4 during the inactive phase is preferably as rapid as possible.
An example may illustrate the considerations on the subject of the speed of displacement of the tube 4.
EXAMPLE 1
Extrusion of high-density polyethylene pipe
For an extrusion output of 200 kg/h and a pipe of outside diameter 160 mm and of wall thickness 9.5 mm, the extrusion speed is 750 mm/min. If it is desired to remove 50% of the heat emitted by the wall above 100° C. by internal cooling, it will be necessary to remove about 6000 kcal/h for a (pipe) discharge temperature from the extruder of 200° C. and a specific heat of high-density polyethylene of 0.6 kcal/kg. With a heat of vaporisation of water (at 15° C.) of 590 kcal/g, the quantity of water which is required to be evaporated will be about 10 kg/h.
Starting from the principle that each part of the surface of the pipe wall must be sprayed ten times (at successive intervals), that the effective oscillating stroke of the tube 4 is 750 mm (reference numeral 20 in FIG. 1) and that the speed of the tube (in the active phase) is set at 7500 mm/min, 10 strokes per minute will be required (provided that the short time of the return stroke--the inactive phase--is neglected).
Returning to FIG. 1, reference numerals 21 and 22 represent the admission of the cooling agent, generally water, and the admission of air used as the propellant gas for the cooling agent, respectively.
The tube 4 comprises a dispersing ejector 23 in the form of an injector, spray nozzle or atomizer at its front end (the opposite end from the rack 14). The Figure shows the two extreme positions of the tube during cooling (the fully advanced position and the withdrawn position). According to an advantageous embodiment of the invention, the injector is constructed so as to produce a rotating cone of dispersed droplets. The advantage of rotating the dispersed droplets results from the fact that the cooling agent forms fine and extremely fine droplets which produce direct and indirect wetting of the wall to be cooled. On account of the centrifugal force the fine droplets flow against the wall, whilst the extremely fine droplets form a mist in the propellant air which flows axially over a long distance (cyclone principle). Dispersion by means of the injector and the rotation of the cone therefore provides a double cooling effect; direct cooling by the droplets and secondary cooling caused by the mist.
FIG. 2 illustrates the circulation of the cooling agent in the atomising cone 24.
With reference to FIG. 3, this shows in detail an example of an injector which produces a rotating cone. It comprises a channel 32 in the centre for the propellant air (primary air) surrounded by a channel 31 for introducing the cooling agent with the secondary air. The two channels terminate in a part in the form of a nozzle 33. In the ends of the channels 31 and 32, just in front of the nozzle 33, the injector comprises vanes 34 which produce a rotating cone of dispersed droplets. The channels 31 and 32 are connected to the inlets 21 and 22 (FIG. 1) and comprise a metering pump (not shown) for the admission of cooling agent, which enables the necessary quantity of cooling agent to be regulated. The injector is designed so that it can be introduced into or withdrawn from the chuck without problems.
It is clear that the invention is not restricted to the example described. Any system of dispersing or atomising a cooling agent inside an extruded pipe which gives rise to successive dispersions in such a way that the cooling agent is dispersed on the wall and that when the cooling agent has evaporated cooling agent is again dispersed on the wall provides the effect sought by the invention.
This may be achieved for example by any system for dispersing a cooling agent inside an extruded pipe which can be displaced in a reciprocating axial movement. All such systems fall within the scope of the invention.
It is advantageous, but not essential, if the injector is equipped with means providing a rotating cone of dispersion.
It is evident that the cooling system described may suitably be combined with conventional cooling of the extruded pipe, i.e. by a cooling agent acting on the external wall surface of the pipe. Other advantageous arrangements will be apparent to the skilled person which do not depart from the spirit of the invention which is defined in the appended claims. | The invention proposes an improved process and a device for cooling the internal surface of the wall of a pipe made of plastic during its manufacture by extrusion. The cooling agent is dispersed on the internal surface of the pipe by successive atomization at given time intervals. The cooling agent is advantageously dispersed by means of an injection which is displaced axially inside the pipe in a reciprocating movement. The injector may be advantageously equipped with means providing a rotating cone of dispersed droplets. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2011-0055338, filed on Jun. 8, 2011, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates to a solar power conversion apparatus, and more particularly, to a solar power conversion apparatus using a neutral-point-clamped multilevel method as a hybrid method and having higher output level and lower distortion than a solar power conversion apparatus of the related art.
[0003] Solar power conversion apparatuses are apparatuses for converting a direct current generated in solar cells to an alternating current and transmit the alternating current to a gird. Full bridge type hardware is mainly used in solar power conversion. However, because of bad quality of power and low efficiency, recently, studies and demands on multilevel power conversion products are increasing.
[0004] Solar power conversion apparatuses of the related art have low power conversion efficiency because solar power conversion is inefficient and whole arrays are used as one input. Also, because of being operated usually in two or three output levels, solar power conversion apparatuses of the related art may have some problems such as not various power levels, low quality of power, and impossible modularization.
[0005] In order to solve those problems mentioned above, a multilevel power conversion apparatus has been developed. A multilevel power conversion apparatus has better efficiency and more stable quality than a full bridge type. There are three multilevel power conversion apparatus topologies: an H-bridge, a neutral-point-clamped, and a flying capacitor.
[0006] However, such a multilevel type also has a little high distortion and low power level.
SUMMARY
[0007] Embodiments provide a solar power conversion apparatus using multi levels, and more particularly, a solar power conversion apparatus having lower distortion and higher output level than a related art solar power conversion apparatus by using a neutral-point-clamped multilevel method.
[0008] Embodiments also provide a solar power conversion apparatus having high efficiency by connecting two solar cells generating electric energy to a module as a solar power converting unit in order to increase efficiency.
[0009] In one embodiment, a solar power conversion apparatus includes: at least one solar array receiving light and generating a DC power; a converter unit converting amplitude of the generated DC power; a multilevel inverter unit receiving the DC power from the converter unit to output AC power with multi levels and comprising a plurality of multilevel inverters; an AC filter insulating the inverter unit from a power grid; and a control unit applying a control signal to the converter unit and the multilevel inverter.
[0010] Also, the converter unit may include at least one converter corresponding to the number of the solar arrays.
[0011] Also, the number of the multilevel inverters connected may correspond to the number of the converters.
[0012] Also, when a plurality of the multilevel inverters are connected in series, each of the multi level inverters may output power of five levels.
[0013] Also, when a plurality of the multilevel inverters connected in series, the multilevel inverters may output power of nine levels.
[0014] Also, the multilevel inverters may include: a plurality of switching elements; a plurality of clamping diodes connected between the switching elements; and a plurality of bus capacitors.
[0015] Also, the switching elements may be insulated gate bipolar transistors (IGBTs).
[0016] Also, the multilevel inverter unit may include (m −1 ) clamping diodes where the m denotes the number of output levels.
[0017] Also, the multilevel inverter unit may include (m−1)/2 DC bus capacitors limiting a ripple of DC power.
[0018] Also, the multilevel inverter unit may generate five power levels according to turned-on states of switching element of the multilevel inverter unit.
[0019] Also, the control unit may include: a converter gating unit for applying a gating signal to perform MPPT (maximum power point tracking) control on the converter; and an inverter gating unit for applying a gating signal to control the inverter
[0020] Also, the gating signal may be a PWM signal based on a carrier or a space vector PWM signal.
[0021] Also, the converter unit may perform maximum power point tracking (MPPT) control about the DC power.
[0022] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a block diagram schematically illustrating a solar power conversion apparatus according to an embodiment.
[0024] FIG. 2 is a view illustrating the solar power conversion apparatus in detail according to the embodiment.
[0025] FIG. 3 is a view illustrating one operation of the solar array, the DC-DC converter, and the multilevel inverter according to the embodiment.
[0026] FIG. 4 is a view illustrating states of the switching elements in the inverter according to each output level of the embodiment.
[0027] FIG. 5 is a view showing a switching order of the switching elements in the inverter according to the embodiment.
[0028] FIG. 6 is a view illustrating an output signal of the solar power conversion apparatus according to the embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.
[0030] It should be understood that the terms and words used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation for the invention.
[0031] Therefore, embodiments described in the specification and the example illustrated in the accompanying drawings herein is just a mere example for the purpose of illustrations only, not intended to represent all the technical aspects of the embodiment, the scope of the invention, so it should be understood that various equivalents and modifications thereof could be made at the time of filing.
[0032] FIG. 1 is a block diagram schematically illustrating a solar power conversion apparatus according to an embodiment.
[0033] Referring to FIG. 1 , a solar power conversion apparatus 10 includes the first and second solar arrays 11 and 12 , a converter 20 , a multilevel inverter 30 , an AC filter 40 , a transformer 50 , and a control unit 60 .
[0034] The solar arrays 11 and 12 receive light and generate DC power. That is, the solar arrays 11 and 12 may be solar cell arrays in which a plurality of solar cells are arranged to receive sunlight and generate power.
[0035] The converter 20 may include a DC-DC converter or a plurality of DC-DC converters respectively corresponding to the first and second solar arrays 11 and 12 .
[0036] The multilevel inverter 30 may include a first multilevel inverter 31 and a second multilevel inverter 32 . The first and second multilevel inverters 31 and 32 may output five power levels, respectively. If the first and second multilevel inverters 31 and 32 are connected in series, the first and second multilevel inverters 31 and 32 may output nine power levels. That is, the output level of the first and the second multilevel inverters 31 and 32 may depend on the configuration of the multilevel inverter 30 .
[0037] In addition, although the first and the second multilevel inverters 31 and 32 are connected in series to generate nine power levels normally, if an error occurs at one of the first and the second multilevel inverters 31 and 32 , the other normal multilevel inverter may be operated alone to output five power levels.
[0038] The AC filter 40 insulates the inverter 30 from a power grid.
[0039] The control unit 60 may apply a control signal to the converter and the multilevel inverter 30 .
[0040] FIG. 2 is a view illustrating the solar power conversion apparatus in detail according to the embodiment.
[0041] Referring to FIG. 2 , first and second converters 21 and 22 of the AC-DC converter 20 may include diodes D 1 , D 2 , D 3 , and D 4 , capacitors C 1 and C 2 , inductors L 1 and L 2 , and switching elements T 1 and T 2 , respectively.
[0042] The multilevel inverter 30 may include a plurality of switching elements, an insulated gate bipolar (IGBT), and a bus capacitor limiting a ripple of DC voltage. The respective inverters 31 and 32 are connected in series. The detail structure and operation of the multilevel inverter 30 will be described later.
[0043] The control unit 60 may include a converter gating unit 61 and an inverter gating unit 62 .
[0044] The converter gating unit 61 applies a gating signal to the converter 20 for maximum power point tracking (MPPT) control.
[0045] The inverter gating unit 62 applies a gating signal for controlling the operation of the inverter 30 . The inverter gating unit 62 may use a pulse width modulation signal (PWM) signal based on a carrier or a space vector PWM signal as a gating signal for controlling the operation of the inverter 30 .
[0046] FIG. 3 is a view illustrating one operation of the solar array, the DC-DC converter, and the multilevel inverter according to the embodiment. If one of the inverters 31 and 32 of the solar power conversion apparatus in FIG. 2 cannot be operated due to an error, the apparatus may be operated on the condition illustrated in FIG. 3 .
[0047] A DC power generated in the solar array 11 is MPPT-controlled by the converter 21 in order to output a maximum output value and is transmitted to the multilevel inverter 31 . The first converter 21 and the inverter 31 may be controlled by gating signals of the control unit 60 , respectively.
[0048] The inverter 31 may output total five power levels according to the gating signal of the control unit 60 . The inverter 31 may include a plurality of switching elements and two bust capacitors C 3 and C 4 limiting a ripple of DC voltage. Also as illustrated in FIG. 3 , the switching elements are arranged in two rows each having 4 elements, and clamping diodes may be arranged between the switching elements. The switching elements may preferably be insulated gate bipolar transistors (IGBTs).
[0049] FIG. 4 is a view illustrating states of the switching elements in the inverter according to each output level of the embodiment.
[0050] The multilevel inverter 31 may output total five power levels such as 2E, E, 0, −E, and −2E. ‘2E’ means a voltage of power applied to the inverter 31 . When outputting the power levels such as 2E, E, 0, −E, and −2E, the switching elements may be turned on as shown in the table of FIG. 5 .
[0051] FIG. 5 is a view showing a switching order of the switching elements in the inverter according to the embodiment.
[0052] As shown in FIG. 5 , if the state of switching is 1, the switching element may be on. If the state of switching also is 0, the switching element may be off. The five power levels may be generated by turning on the switching elements in an order according to a system clock as described above.
[0053] In FIG. 3 or FIG. 4 , the multilevel inverter 31 includes four pairs of interacting IGBT switches: (TA 11 +, TA 11 −), (TA 22 +, TA 22 −), (TB 11 +, TB 11 −), and (TB 22 +, TB 22 −).
[0054] In FIG. 4 , (a), (b), (c), and (d) are exemplary views illustrating turned-on states of the switching elements according to output levels, wherein (a) shows the output power level 2E, (b) shows the output power level E, (C) shows the output power level −E, and (d) shows the output power level −2E.
[0055] Meanwhile, the number of elements required according to the number (m) of outputting multi levels is shown in Table 1 below.
[0000]
TABLE 1
Flying
H-bridge
Capacitor
cascade
Diode clamp
Hybrid diode
method
method
method
clamp method
Main
(m − 1) × 2
(m − 1) × 2
(m − 1) × 2
(m − 1) × 2
switching
element
Clamping
0
0
(m − 1) ×
(m − 1)
diode
(m − 2)
DC bus
(m − 1)
(m − 1 )/2
(m − 1)
(m − 1)/2
capacitor
Balance
(m − 1 ) ×
0
0
0
capacitor
(m − 2)/2
[0056] In Table 1, the hybrid diode clamp method is the method that the multilevel inverters are connected in series according to the embodiment.
[0057] Also, if two multilevel inverters are connected in series as illustrated in FIG. 2 , total nine power levels such as 4E, 3E, 2E, E, 0, −E, −2E, −3E, and −4E, may be outputted.
[0058] FIG. 6 is a view illustrating an output signal of the solar power conversion apparatus according to the embodiment.
[0059] As illustrated in FIG. 6 , a signal of a required power level may be extracted from the output signal and then be transmitted to the power grid.
[0060] Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. | Provided is a solar power conversion apparatus which includes at least one solar array receiving light and generating a DC power, a converter unit converting amplitude of the generated DC power, a multilevel inverter unit receiving the DC power from the converter unit to output AC power with multi levels and comprising a plurality of multilevel inverters, an AC filter insulating the inverter unit from a power grid, and a control unit applying a control signal to the converter unit and the multilevel inverter. | 8 |
RELATED APPLICATIONS
[0001] This application is a Continuation application of U.S. patent application Ser. No. 11/361,987 filed Feb. 27, 2006, which is a Continuation application of U.S. application Ser. No. 10/338,884, filed Jan. 9, 2003 now U.S. Pat. No. 7,018,745, which is a Continuation of U.S. application Ser. No. 09/674,302, filed Jan. 16, 2001, which is the U.S. National Stage of PCT/AU99/00417 filed May 29, 1999, which claims priority from Australian Application No. PP3816 filed May 19, 1998. The subject matter of which are incorporated fully by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of constructing Bragg gratings or the like in UV or like photosensitive waveguides utilizing a UV or like interference pattern.
BACKGROUND OF THE INVENTION
[0003] The present invention is directed to writing gratings or other structures in a photosensitive optical waveguide. The creation of a grating utilizing the interference pattern from two interfering coherent UV beams is well known. This technique for construction of Bragg gratings is fully described in U.S. Pat. No. 4,725,110 issued to W H Glenn et al and U.S. Pat. No. 4,807,950 issued to W H Glenn et al.
[0004] Bragg grating structures have become increasingly useful and the demand for longer and longer grating structures having higher and higher quality properties has lead to the general need to create improved grating structures.
SUMMARY OF THE INVENTION
[0005] In accordance with a first aspect of the present invention there is provided a method of writing an extended grating structure in a photosensitive waveguide comprising the steps of utilising at least two overlapping beams of light to form an interference pattern, moving the waveguide through said overlapping beams, simultaneously controlling a relative phase delay between the beams utilising a phase modulator, thereby controlling the positions of maxima within said interference pattern to move at approximately the same velocity as the photosensitive waveguide, wherein the phase modulator does not comprise a mechanical means for effecting the phase modulation, and modifying the relative phase delay between the beams during the writing of the grating structure, whereby a deliberate detuning of the velocity of the positions of maxima within said interference pattern and the velocity of the photosensitive waveguide is utilised to vary a period of the written grating structure in the photosensitive waveguide.
[0006] Preferably, the at least two overlapping beams are formed by the splitting of a single coherent beam of light.
[0007] In one embodiment, the steps of controlling and modifying of the relative phase delay is performed before the splitting of the single coherent beam.
[0008] In one embodiment, the steps of controlling and modifying of the relative phase delay may be performed after the splitting of the single coherent beam.
[0009] In one embodiment, the steps of controlling and modifying of the relative phase delay is performed prior to the splitting of the single coherent beam.
[0010] Said modulator may comprise one or more of a group comprising an electro-optic phase modulator, a magneto-optic phase modulator, a frequency shifter, an acousto-optic frequency shifter, a controllable optical retarder, and an optical delay line.
[0011] In one embodiment, the method further comprises, after the splitting of the single coherent beam, the step of reflecting said beams at a series of reflection elements for effecting the overlapping of the beams to form the interference pattern.
[0012] The method may further comprise utilising a feedback loop in controlling and modifying of the phase delay to improve the noise properties of the grating structure. The feedback loop comprises an opto-electronic feedback loop.
[0013] The grating structure may comprise a chirped grating and/or an apodized grating.
[0014] The grating structure may have one or more of a group comprising a predetermined strength profile, a predetermined period profile, and a predetermined phase profile.
[0015] In one embodiment, the two beams have substantially orthogonal polarization states and wherein the modulator modulates the relative phase delay between the polarization states and wherein the method further comprises the step of aligning the polarization states of the beams subsequent to modulating the relative phase delay for forming the interference pattern.
[0016] The two beams having the substantially orthogonal polarization states may initially from a single beam of light, and a polarization splitter element is utilised to separate the two beams from each other. The modulator may modulate the relative phase delay between the polarisation states in the single beam.
[0017] According to one embodiment, there is provided a method of writing a grating structure with at least one of predetermined amplitude, period and phase properties in a photosensitive waveguide. The method comprises: providing at least two light beams which overlap in an overlap region to form an interference pattern; moving the photosensitive waveguide through the overlap region; and modulating the phase of at least one of the light beams relative to the phase of the other light beams using a non-mechanical beam modulator so that the interference pattern appears to move through the overlap region, the apparent movement being variably controlled in response to the movement of the photosensitive waveguide such that a grating structure is written with the at least one of predetermined amplitude, period and phase properties.
[0018] In accordance with a second aspect of the present invention, there is provided a device for writing an extended grating structure in a photosensitive waveguide comprising an interferometer arranged to form an interference pattern utilising at least two overlapping beams of light; a phase modulator for controlling a relative phase delay between the beams whereby, in use, the positions of maxima within said interference pattern are controlled to move at approximately the same velocity as the photosensitive waveguide moving through said overlapping beams, wherein the phase modulator does not comprise a mechanical means for effecting the phase modulation, and wherein the phase modulator is arranged, in use, to modify the relative phase delay between the beams during the writing of the grating structure, whereby a deliberate detuning of the velocity of the positions of maxima within said interference pattern and the velocity of the photosensitive waveguide is utilised to vary a period of the written grating structure in the photosensitive waveguide.
[0019] Preferably, the device comprises a beam splitter element for splitting of a single coherent beam of light into said at least two overlapping beams.
[0020] In one embodiment, the device is arranged, in use, such that the controlling and modifying of the relative phase delay is performed before the splitting of the single coherent beam.
[0021] In one embodiment, the device is arranged, in use, such that the controlling and modifying of the relative phase delay is performed after the splitting of the single coherent beam.
[0022] In one embodiment, the device is arranged, in use, such that the controlling and modifying of the relative phase delay is performed prior to the splitting of the single coherent beam.
[0023] Said modulator may comprise one or more of a group comprising an electro-optic phase modulator, a magneto-optic phase modulator, a frequency shifter, an acousto-optic frequency shifter, a controllable optical retarder, and an optical delay line.
[0024] In one embodiment, the device further comprises a series of optical reflection elements for effecting the overlapping of the beams to form the interference pattern.
[0025] The device may further comprise a feedback unit for facilitating the controlling and modifying of the phase delay to improve the noise properties of the grating structure. The feedback unit may comprise an opto-electronic feedback loop.
[0026] In one embodiment, the two beams have substantially orthogonal polarization states and the modulator is arranged, in use, to modulate the relative phase delay between the polarization states and wherein the device further comprises a polarisation manipulation element for aligning the polarization states of the beams subsequent to modulating the relative phase delay for forming the interference pattern.
[0027] The two beams having the substantially orthogonal polarization states may initially from a single beam of light, and the device compresses a polarization splitter element for separating the two beams from each other.
[0028] The modulator may be arranged, in use, to modulate the relative phase delay between the polarisation states in the single beam.
[0029] According to one embodiment, there is provided an apparatus for variably controlling the apparent movement of an interference pattern with reference to a moving photosensitive waveguide to write a grating structure in the photosensitive waveguide. The apparatus comprises: at least one light beam source for providing at least two light beams; a beam director for directing at least one of the light beams so that the light beams overlap in an overlap region to form the interference pattern; at least one non-mechanical beam modulator for modulating the phase of at least one of the light beams relative to the phase of the other light beams so that the interference pattern appears to move through the overlap region; and a beam modulator controller for controlling the modulation of the beam modulator so that the apparent movement of the interference pattern is variably controlled in response to the movement of the photosensitive waveguide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0031] FIG. 1 illustrates schematically a first embodiment of the present invention;
[0032] FIG. 2 illustrates one form of driving of the electro-optic modulator in accordance with the principles of the present invention;
[0033] FIG. 3 illustrates an alternative embodiment of the present invention; and
[0034] FIG. 4 illustrates a further alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0035] Turning initially to FIG. 1 , there is illustrated the arrangement 1 of a preferred embodiment which is similar to the aforementioned arrangement of Glenn et al with the additional inclusion of an optical phase modulating element 2 . The basic operation of the arrangement of FIG. 1 is that a UV source 3 undergoes beam splitting by beamsplitter 4 so as to form two coherent beams 5 , 6 . A phase mask placed appropriately into a setup can be used to split the beam. Each beam is reflected by a suitably positioned mirror e.g. 7 , 8 so that the beams interfere in the region 9 . In this region, there is placed a photosensitive optical waveguide 10 on which an extended grating structure is to be written. The essence of the preferred embodiment is to utilize the phase modulator 2 so as to modulate the relative phase difference between the two beams 5 , 6 at the point of interference 9 such that the interference pattern remains static in the reference frame of the optical waveguide 10 as the waveguide is moved generally in the direction 12 . The phase modulator 2 can be an electro-optic modulator of a known type including an ADP, KD*P, BBO crystal type transparent at the UV source wavelength. Suitable electro-optic crystals are available from many optical components manufacturers including Leysop Limited under the model numbers EM200A and EM200K. The modulator operates so as to provide for a controlled phase delay of the beam 5 relative to the beam 6 . In a first example, the control is achieved by setting the level of an input signal given the fibre 10 is moving at a constant velocity. The input signal in this case can comprise a saw tooth wave form as illustrated in FIG. 2 , the maximum saw tooth magnitude being set to be equivalent to a 2π phase delay. The slope of the saw tooth wave form is set so as to closely match the velocity of the changing maxima of the interference pattern to that of the fibre 10 .
[0036] Hence, prior known mechanical methods of movement of the portion of the apparatus is dispensed with and long or stitched interference patterns can be obtained through the utilization of the phase modulating device 2 to introduce the required optical phase difference between the interfering UV beams 5 and 6 . AS the phase is invariant with respect to a 2π change, there is no need to introduce large phase differences thus limiting the required amplitude of the phase change to 2π and allowing it to operate near the balance point of the interferometer. The electro-optically induced phase change will make the interference pattern move along the fibre as the fibre itself moves and the direction and velocity of the move can be set in accordance with requirements. The saw tooth wave form achieving the effect of “running lights”.
[0037] Electro-optic modulators such as those aforementioned can operate with very low response time and extremely high cut off frequencies. Hence, the saw tooth edge fall can be practically invisible and a near perfect stitch can be achieved. At 6 mm per minute scanning speed, the modulation frequency can be about 200 Hz.
[0038] Further, by applying a differential velocity between the fibre and the pattern or through appropriate control of the phase delay, a wavelength shift with respect to the static case can be obtained. An acceleration or appropriate control of the phase delay can be used to produce a chirp and so on. Apodisation can also be provided by proper additional modulation of the electro-optic modulator.
[0039] The embodiment described has an advantage of having all optical elements static except for the moving fibre. Therefore, it allow for focussing of the interfering beams tightly onto the fibre and achieving spatial resolution reaching fundamental limits (of the order of the UV writing wavelength, the practical limit being the fibre core diameter). The static interferometer arrangement itself leads to reduced phase and amplitude noise of the interference pattern. Additionally, the ability to control the phase and amplitude of the pattern using a feedback loop provides a means to improve the noise properties of the interferometer substantially.
[0040] A number of further refinements are possible. For example, in order to accurately match the velocity of the fibre 10 and the electro-optic modulator frequency, a simple scanning Fabry-Perot interferometeric sensor can be used to measure the relative positions of the fibre and the interference pattern 9 . A high finesse (F) resonator can be used to achieve the accuracy of distance measurements much better than the wavelength of the narrow line width source which would be employed in the sensor.
[0041] By scanning the Fabry-Perot at a constant rate or sweeping the laser frequency the position can be precisely (½F) determined. To increase the resolution further a conversion of the interferometer into a laser at threshold may be needed. In this case the finesse F of the cavity is close to infinity and the resolution is enhanced. Other types of interferometric sensors such as a Michelson interferometer can be used to accurately determine the fibre position with respect to the interference pattern.
[0042] Of course, other arrangements utilizing this principle are possible. For example, the teachings of PCT patent application no. PCT/AU96/00782 by Ouellette et al discloses an improved low noise sensitivity interferometric arrangement which operates on a “Sagnac loop” type arrangement. Turning now to FIG. 3 there is illustrated a modified form of the Ouellette arrangement to incorporate the principles of the present invention. In this modified form, an initial input UV beam 20 is diffracted by phase mask 21 so as to produce two output beams 22 , 23 . The beam 23 is reflected by mirrors 24 , 25 so as to fall upon the fibre 26 in the area 27 . Similarly, beam 22 is reflected by mirror 25 and mirror 24 before passing through an electro-optic modulator 28 which modifies the phase of the beam relative to the beam 23 . The two beams interfere in the area 27 . The phase of the interference patterns can be controlled by the modulator 28 in the same manner as the aforementioned. In this manner, the advantages of the previous Ouellette arrangement can be utilized in a stable mechanical arrangement in that it is not necessary to sweep the beam across the phase mask 21 or perform any other movements other than the electrical modulation of the modulator element 28 whilst forming an extended grating structure. Moreover, the interferometer can be adjusted to operate near its balance point and a low coherence length UV source can be used in the arrangement.
[0043] Further, a phase modulator based on a magneto-optic effect could be used instead of an electro-optic modulator. In the Sagnac interferometer arrangement, it can be placed such that both of the interfering beams pass the Faraday cell in opposite directions such that a non-reciprocal controlled relative phase delay is introduced between the counter propagating beams.
[0044] Turning now to FIG. 4 there is illustrated an alternative arrangement to incorporate the principles of the present invention. In this arrangement, the output from a UV laser 30 is initially linearly polarized 31 before passing through an electro-optic modulator 32 which modifies the polarization state of the beam. The polarization plane of the UV beam with respect to the birefringent axes of the electro-optic modulator 32 is such that two orthogonal polarization eigenstates with equal intensities propagate in the modulator, with one of the eigenstates being phase modulated while the other one being not. The arrangement uses polarization beam splitter 33 to separate the polarization states and half-wave plate 34 is used to 90 degree rotate the polarization of one of the resulting beams to allow for the interference taking place between the beams. The beams are further reflected by mirrors 36 and 37 so as to fall upon the fibre 38 in the area 39 to produce an interference pattern in conjunction with movement of the fibre 38 . The phase of the interference pattern can be controlled by the modulator 32 in the same manner as the aforementioned to produce an extended grating structure.
[0045] In a further alternative embodiment, a travelling wave acousto-optic (AO) modulator transparent at the wavelength of the UV source 3 can be used as a modulating element 2 to frequency shift the diffracted light. The interference between the two beams at different frequencies in region 9 will result in a interference pattern travelling at a velocity v=Δν·Λ/2. For example, for Δν=200 Hz frequency shift and Λ/2=1 μm interference pattern period the velocity of the pattern is v=6 mm/min and the optical waveguide 10 should be translated at this speed in the same direction. No special modulation waveforms need to be applied in this case, with the control parameter being the frequency shift. As most commercial acousto-optic modulators operate in a MHz range, a frequency shift of the second interfering beam may be required to achieve the differential frequency shift in the Hz-kHz range. There may be also need for a minor adjustment compared to the electro-optic modulator arrangement of FIG. 2 as the Bragg angle will vary with the frequency of the applied to the AO modulator signal resulting in a displacement of the diffracted beam. However the effect of this displacement can be reduced by making the setup compact. There could also be a further adjustment since AO modulators may exhibit resonances.
[0046] In a modified embodiment, an optical phase mask, optical wedge or an optical waveplate can be utilized. The optical phase mask can also have a function of the beamsplitter. The embodiment utilizing the phase mask works for all known phase-mask based interferometer arrangements, such as phase mask direct writing technique, or for a Sagnac interferometer writing technique (such as that due to Ouellette disclosed on PCT application number PCT/AU96/00782) or when utilizing the aforementioned system due to Glenn et al.
[0047] It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive. | A method of writing a grating structure with at least one of predetermined amplitude, period and phase properties in a photosensitive waveguide, the method comprising providing at least two light beams which overlap in an overlap region to form an interference pattern; moving the photosensitive waveguide through the overlap region; and modulating the phase of at least one of the light beams relative to the phase of the other light beams using a non-mechanical beam modulator so that the interference pattern appears to move through the overlap region, the apparent movement being variably controlled in response to the movement of the photosensitive waveguide such that a grating structure is written with the at least one of predetermined amplitude, period and phase properties. The apparent movement of the interference pattern may be variably controlled to match the movement of the waveguide, or to be deliberately detuned. The grating structure may be chirped or apodized. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates in general to sigma-delta modulators and, more particularly, to a method of improving the signal/noise ratio of a sigma-delta modulator during the re-establishment of its stability, and to a circuit that uses the method.
[0003] 2. Description of the Related Art
[0004] As is known, sigma-delta modulation is a technique which enables a high-resolution analogue-digital conversion to be achieved. According to this technique, an analogue signal is “over-sampled,” that is, it is sampled at a rate much faster than is necessary for a conventional analogue-digital converter operating at the Nyquist rate. A sigma-delta modulator integrates the analogue signal and performs a conventional delta modulation on the integral of the signal. For this purpose, the modulator uses a low-resolution quantizer. The output signal of the quantizer is added, with its sign reversed, to the analogue input signal, by a feedback loop containing a digital-analogue converter.
[0005] To produce a digital signal corresponding to the analogue input signal, the signal output by the modulator is subjected to the action of a so-called digital decimation filter which produces a digital output signal with a sampling rate equal to twice the Nyquist rate. By virtue of the over-sampling and of the digital decimation, this technique achieves a better resolution and less distortion than can be achieved with the technique of conversion at the Nyquist rate. Moreover, since the error signal, that is, the difference between the input signal and the sampled signal, is integrated, the sigma-delta modulator acts as a low-pass filter for the signal and as a high-pass filter for the quantization noise. It thus attenuates the noise in the signal band particularly effectively.
[0006] The noise attenuation is appreciable even with a first-order sigma-delta modulator, that is, a sigma-delta modulator comprising a single integrator upstream of the quantizer; however, to achieve the high signal-noise ratios required of high-resolution analogue-digital converters, it is necessary to use higher-order modulators, that is, modulators comprising several integrators in cascade.
[0007] With a higher-order modulator, however, problems of stability arise. The system may in fact be stable or unstable in dependence on the type of input signal (in particular, it is unstable for signals which exceed the input volume range of the circuit), in dependence on the starting conditions upon switching-on, and in dependence on the presence of any fluctuations in the supply voltage.
[0008] As soon as there is a departure from ideal operating conditions and, more precisely, when the gain of an element of the feedback loop falls below a certain limit, the modulator becomes unstable and tends to oscillate. The quantizer is an element of the feedback loop. The gain of the feedback loop is subject to variations as the operating conditions vary. Conditions of instability arise when the voltages of the internal analogue nodes reach values above the maximum design swing. In order to re-establish conditions of stability, intervention from outside the circuit is required. Various methods of doing this have been proposed and differ from one another in the manner in which the instability is detected and in the action undertaken to re-establish stability.
[0009] A first method provides for the connection of limiter elements in parallel with the capacitors of the integrators. The selection of the thresholds of the limiters is critical; in fact, if the thresholds are close to the limits of the dynamic range of the operational amplifiers of the integrators, the signal may also be limited during normal operation with high input signal levels, causing distortion; if, however, the thresholds are too low, there is a low signal/noise ratio. This solution cannot therefore be used in applications in which linearity is essential and a high signal/noise ratio is required.
[0010] A second method provides for detection of the oscillation which occurs in conditions of instability by measuring the analogue voltages of the internal nodes of the circuit and comparing them with respective predetermined reference values. If the reference values are exceeded, the system is considered unstable and the state variables of the modulator are reset to zero. In this case also, unnecessary limitations may occur since, in normal operation, some internal nodes may often be overloaded temporarily without this necessarily causing a condition of instability.
[0011] It has also been proposed to allow the modulator to become unstable and to detect the instability by monitoring the digital output signal. More particularly, a sequence of bits which corresponds to an instability state is defined and the output flow of bits is kept under surveillance in order to identify the appearance of such a sequence and consequently to indicate an instability state. As soon as the instability is detected, the output voltages of all of the integrators, or at least of some of them, are reset to zero so that, if the cause of the instability has ceased, the modulator is returned to stable operating conditions.
[0012] This technique has the advantage of avoiding unnecessary limitations during normal operation since the resetting operation is enabled only when an instability state has occurred. However, the time required to detect the instability is not always negligible so that, before the modulator is reset and returned to normal operating conditions, a residual output signal is present which degrades the signal/noise ratio in a manner which may be unacceptable in some applications. This phenomenon becomes very noticeable in the event of overloads which persist for long periods, causing repeated resetting operations.
BRIEF SUMMARY OF THE INVENTION
[0013] The disclosed embodiments of the present invention provide a method that ensures a sufficiently high signal/noise ratio of the sigma-delta modulator, even during detection and stability re-establishment operations. A circuit for implementing the method is also provided.
[0014] In accordance with a method of the present invention, the signal-to-noise ratio of a sigma-delta modulator is improved during the re-establishment of its stability by defining a bit sequence corresponding to a state of instability of the modulator; monitoring the flow of bits output by the modulator to check whether it contains the instability bit sequence; and resetting the modulator to zero if the instability bit sequence is detected at the output, including delaying the flow of bits output by the modulator at least for the time required to detect the instability bit sequence, and modifying the output bit sequence during the delay time by replacing it with a predetermined bit sequence.
[0015] In accordance with another embodiment of the invention, a circuit is provided that includes a sigma-delta modulator having an analog signal input which is also the output of the circuit, a digital signal output, and at least one zero-resetting input; and a control logic unit connected to the output of the modulator and to the zero-resetting input and comprising means for storing a sequence of output bits corresponding to a state of instability of the modulator, means for monitoring the flow of bits output by the modulator, and means for applying zero-setting signals to the zero-setting input of the modulator when the instability sequence is identified in the flow of bits output by the modulator, a shift register having a data input connected to the output of the modulator, a data output that is also the output of the circuit, and a setting input, the control logic unit including means for applying a setting signal to the setting input of the shift register when the instability sequence is identified in the flow of bits output by the modulator.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0016] The invention will be understood better from the following detailed description of a non-limiting embodiment, given with reference to the appended drawings, in which:
[0017] [0017]FIG. 1 is a block diagram of a conventional, first-order sigma-delta modulator,
[0018] [0018]FIG. 2 is a block diagram of a circuit with a band-pass sigma-delta modulator according to the invention, and
[0019] [0019]FIGS. 3A and 3B show the output spectrum for a −20 dB input signal, measured at two nodes of the circuit with the sigma-delta modulator according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] [0020]FIG. 1 shows a conventional sigma-delta modulator that includes an analogue-digital converter (A/D) or quantizer 10 and a feedback circuit constituted by an adder node 11 , an integrator (H) 12 , and a digital-analogue converter (D/A) 13 . An analogue input signal X(z) is applied to the adder node 11 . The output signal of the adder node is integrated by the integrator 12 and is then converted into digital form by the quantizer 10 . The conversion takes place at a sampling frequency fs. The digital output Y(z) of the modulator is returned to analogue form by the digital-analogue converter 13 and is applied, with its sign reversed, to the adder node 11 .
[0021] The adder node 11 thus supplies an error signal to the integrator 12 . The effect of the feedback loop is such that the output Y(z) is a digital signal which oscillates about the value of the analogue input signal. The energy of this oscillating signal constitutes the quantization noise. The quantizer 10 and the digital-analogue converter 13 are typically single-bit converters and the quantization noise is therefore high. It can be shown that the transfer function Y(z)/X(z) of the signal is that of a low-pass filter the pass-band of which is determined by the characteristics of the integrator 12 , and the transfer function of the noise is that of a high-pass filter the pass-band of which is determined by the sampling frequency fs. If the output of the modulator is connected to a decimation filter, the resulting circuit is an analogue-digital converter. With an appropriate selection of the cut-off frequency of the decimation filter, the input signal is not attenuated significantly, whereas the quantization noise is greatly attenuated.
[0022] As already mentioned, to achieve a considerable attenuation of the quantization noise, as is necessary to produce high-resolution analogue-digital converters, it is necessary to use modulators of an order higher than one.
[0023] The embodiment of the invention shown in FIG. 2 has a circuit with a sixth-order modulator, that is, a modulator comprising six integrators, indicated H 1 -H 6 , in cascade. The input terminal of each integrator is connected to the output terminal of the preceding integrator by means of an adder. An input signal is applied to the various adders with different weights determined by suitable connection means with scale factors a 1 -a 6 . The output terminal of the last integrator H 6 is connected to the input terminal of a single-bit analogue-digital converter or quantizer 20 the output OUT of which is connected to the data input of a shift register 25 , preferably formed as a FIFO (first-in, first-out) memory. The data output OUT+Δt of the register 25 , which is also the output of the circuit, may be connected to a digital decimation filter, not shown. The output of the quantizer 20 is also connected to the various adders via a digital-analogue converter 21 which is also a single-bit converter, and via suitable connection means with scale factors b 1 -b 6 .
[0024] In this embodiment, the integrators are connected in pairs by suitable feedback means f 1 , f 2 and f 3 to form three resonators HH 1 , HH 2 , HH 3 . The modulator behaves as a band-pass filter the pass-band of which is centered on a frequency other than zero, determined by the feedback means f 1 , f 2 and f 3 . The scale factors and the feedback means are selected so as to achieve the desired transfer functions of the signal and of the noise. A control logic and stabilization unit 22 is connected to the output terminal OUT of the modulator, to a setting input, indicated SET, of the register 25 , and to the integrators, by means of respective zero-resetting terminals. The unit is preferably constituted by a so-called finite states machine (FSM) and is programmed so as to monitor the flow of bits output by the quantizer 20 to check whether a predetermined bit sequence SEQ corresponding to a condition of instability of the modulator appears therein. This sequence can be defined experimentally by bringing about a state of instability of the modulator and observing the output flow of bits. The sequence SEQ is entered and stored in the logic unit 22 . The unit 22 is also programmed to send a zero-resetting signal to the last integrator H 6 as soon as the instability sequence is identified in the output signal. The duration of the zero-resetting signal TRST, which is also entered and stored in the unit 22 , is selected so as to be long enough to ensure effective resetting of the integrator, that is, in practice, to discharge the capacitors of the integrator completely.
[0025] The resetting of the last integrator is normally sufficient to re-establish the stability of the modulator. In fact, an instability situation is caused by an overload at the node between the last integrator and the quantizer so that the gain of the quantizer, indicated k in FIG. 2, is too low and the feedback of the system becomes positive; when the last integrator is reset to zero, the gain of the quantizer increases and the feedback tends to become negative again, restoring the stability of the system. In other words, after the last integrator has been reset to zero and before it is reactivated, the modulator behaves as a modulator of an order lower by one and therefore tends to be more stable.
[0026] It is important to point out that the noise caused by the resetting operation is processed in accordance with the transfer functions of the preceding integrators H 1 to H 5 and that the time required for the modulator to start to operate again is very short since it is due to the recovery time of the last integrator H 6 alone.
[0027] If, after this operation, the unit 22 again identifies the instability sequence in the output flow of bits, a zero-resetting signal is applied both to the integrator H 6 and to the preceding integrator H 5 . If the instability is still not eliminated, the above-described operations are repeated, the number of stages reset being increased by one each time.
[0028] During normal operation of the modulator, the likelihood of finding an instability condition which requires intervention on all of the integrator stages is very low so that, in most cases, the noise of the resetting operation is processed by at least one integrator and the time taken to re-establish the operation of the modulator is always less than that which would be required if all of the integrators were reset simultaneously.
[0029] During normal operation, the register 25 has the sole effect of transferring the flow of data output by the quantizer 20 to the output OUT+Δt of the circuit with a predetermined delay Δt.
[0030] If, however, an instability bit sequence is detected in the flow of data output by the quantizer 20 , the logic circuit 22 applies to the setting input of the register 25 a signal which modifies the bit sequence contained in the register, replacing it with a predetermined bit sequence. In this example, the predetermined bit sequence is a series of zeroes; this corresponds to shifting the energy of the output signal associated with the instability from frequencies within the pass-band of the modulator to a region around the frequency 0 , as shown in FIGS. 3A and 3B for an output spectrum measured for a −20 dB input signal. FIG. 3A shows the effect of an operation to reset the modulator at the output OUT of the quantizer 20 as a result of a voltage peak; the energy contribution caused by the instability is within the pass-band. FIG. 3B shows the same spectrum measured at the output OUT+Δt of the register 25 ; the energy contribution caused by the instability has been shifted out of the pass-band and, more precisely, to the frequency 0 , and can easily be eliminated by suitable digital filters downstream of the modulator. Clearly, the signal/noise ratio of the modulator is thus considerably improved.
[0031] Although only one embodiment of the invention has been described and illustrated, naturally many variations and modifications are possible within the scope of the same inventive concept. For example, the register 25 may be included in the FSM unit 22 and may also serve for the function of monitoring the output flow of bits; it may also be a register other than a FIFO memory, provided that it can temporarily store an adequate number of output bits, and provided that it has means for modifying its content when required. Moreover, the invention may also advantageously be implemented with a low-pass modulator or with a high-pass modulator rather than with a band-pass modulator as described. | A method of improving the signal/noise ratio of a sigma-delta modulator during the re-establishment of its stability that includes: defining a bit sequence corresponding to a state of instability of the modulator, monitoring the flow of bits output by the modulator to check whether it contains the instability bit sequence, and resetting the modulator to zero if the instability bit sequence is detected at the output. To ensure a high signal/noise ratio of the modulator even during the detection and re-establishment of stability, the method also includes: delaying the flow of bits output by the modulator at least for the time required to detect the instability bit sequence and modifying the output bit sequence during the delay period by replacing it with a predetermined bit sequence. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an optical disc recording method apparatus of a mark length recording system in which the laser light is illuminated on a recording surface of an optical disc to form pits for information recording. More particularly, it relates to a method and apparatus for recording an optical disc in which recording is made at a speed higher than a quadrupled speed, such as octupled or duodeca-tupled speed.
[0003] 2. Description of Related Art
[0004] Up to now, in recording the information on a recording medium, such as an optical disc, in accordance with an optical modulation system, thermal control is exercised by pulsed light emission of the laser in order to form pits (marks) optimally on a disc. Specifically, the pulse waveform is set as a driving pulse for driving the laser, while the level (wave crest value) during each pulse period is also controlled to control the laser power and the laser illuminating period.
[0005] For example, in an optical recording and/or reproducing apparatus, typified by a CD-R (CD-Recordable) or CD-RW (CD-ReWritable), a pulse length controlling system or a pulse train recording system is used, in which the pulse length or the number of pulses of the laser light illuminated is varied depending on the recording mark length or space length to be recorded to control the laser power outputting domain.
[0006] The Orange-Book Part 2 (version 3.1), as the latest standard of CD-R, is premised, as the standard per se, on the mono-tupled speed, double-speed and quadrupled speed recording. The laser light emission control related to the write speed, that is recording strategy (recording compensation) is prescribed as shown in FIGS. 1 and 2. That is, in the CD-R standard, the information is recorded on an optical disc by the combination of pits (marks) and lands (spaces) of 3T to 11T. For the recording strategy for mono-tupled speed and double-speed recording, the laser power outputting domain of(n−θ)T+αT is prescribed, where θ=1T and α=0.13T, with the laser power forming nT pits (marks) being Pw, as shown in FIG. 1. For the recording strategy for quadrupled speed recording, (n−θ)T and ODT are prescribed as being output domains of the laser power Pw and the laser power ΔP, respectively, with the laser power forming nT pits (marks) being Pw+ΔP, where ΔP is 20 to 30% of Pw and ODT is set to 1.25T to 1.5T. It is noted that the mono-tupled speed herein means a speed of 1.2 to 1.4 m/s with the disc being run in rotation at a constant linear velocity (CLV).
[0007] Meanwhile, if the recording strategy prescribed by the above-mentioned Orange Book standard, premised on the mono-tupled speed recording, double speed recording and on the quadrupled speed recording, is to be applied to recording at a speed higher than the quadrupled speed, such as octupled speed recording or duodeca-tupled speed recording, thermal interference occurs between the pit and land codes to be recorded, with the result that recording signals are deteriorated in signal quality due to deformed pit shape or to increased jitter.
[0008] That is, the ideal relation between recording data and pits is such that, for recording data with a length equal to nT, a pit with a length equal to nT is formed to an oblong shape, as shown in FIG. 3. If now the octupled speed recording, for example, is to be made with the recording strategy for mono-tupled speed recording and double speed recording, a tear-shaped pit is formed in which the trailing end side of the pit is spread in a direction perpendicular to the track center, as shown in FIG. 4. If the recording strategy for quadrupled speed recording is used, there is again formed a tear-shaped pit which is only slightly improved over the case of the octupled speed recording as to spreading of the pit in the direction perpendicular to the track center, as shown in FIG. 5.
[0009] In FIGS. 4 and 5, the time periods A and B denote time delay as from the turning on of the laser emission until start of the pit forming process. On the other hand, the time periods a, b and c denote time delay as from the turning off of the laser light emission until termination of the pit forming process.
[0010] If the recording signal is deteriorated in quality due to deformed pit shape or increased jitter, there is a risk that regular reproduction cannot be realized.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of the present invention to provide an optical disc recording method and apparatus whereby pits can be formed to an optimal shape at a speed faster than the quadrupled speed, such as an octupled speed or duodeca-tupled speed.
[0012] In one aspect, the present invention provides an optical disc recording apparatus including recording pulse generating means for setting a recording power at approximately the leading end portion of a recording pulse in steps of a plurality of stages and for generating a recording pulse of a pulse width corresponding to a length of a pit to be formed, and laser means for illuminating the laser light by the recording pulse supplied to form a recording data string comprised of pits and lands defined between the lands on a recording medium, wherein the laser light emitting pulsed light by the recording pulse generated by the recording pulse generating means is illuminated on a write-once optical disc as the recording medium to effect recording.
[0013] In another aspect, the present invention provides a recording method for an optical disc including generating a recording pulse having a pulse width corresponding to a length of a pit formed, the recording pulse being so formed that a recording power at approximately the forward end thereof is stepped over plural stages and illuminating a laser light beam, excited in pulsed light by the recording pulse, on a write-once optical disc to effect recording.
[0014] In still another aspect, the present invention provides a recording apparatus for an optical recording medium including means for causing rotation of the recording medium, a controller for controlling the rotational speed of the rotating means, laser means for illuminating the laser light by drive pulses supplied to form a recording data string including a pit and lands ahead and at back of the pit on the recording medium, drive pulse generating means for generating a first pulse corresponding to recording data, a second pulse for synthesis to a leading end of the first pulse and a third pulse for synthesis to a leading end of the first pulse, and for synthesizing the first to third pulses to generate the drive pulse, and pulse generation controlling means for performing control so that the level or the pulse width of one or more of the first to third pulses generated by the drive pulse generating means is varied depending on at least one of the lengths of the pit and the land formed.
[0015] In yet another aspect, the present invention provides a recording method for forming a recording data string including generating a first pulse corresponding to recording data, a second pulse for synthesis to a leading end of the first pulse and a third pulse for synthesis to a leading end of the first pulse, as pulses the level or the pulse duration of which is varied depending on at least one of the length of the pit formed and the length of the land formed, synthesizing the first to third pulses to generate a recording pulse, and illuminating the laser light by the drive pulse to form a recording data string including pits and lands between for and aft side pits on a recording medium rotated at a pre-set speed.
[0016] According to the present invention, as described above, in which the recording pulse with a pulse width corresponding to a length of a pit formed, having a recording power at approximately the forward end thereof stepped over plural stages, is generated, and the laser light excited into pulsed light by the recording pulse is illuminated to effect recording, it becomes possible to reduce thermal interference due to inter-symbol interference between the codes, that is the pits and the lands recorded, with the result that pits/lands may be formed to an optimum shape to enable a sufficient replay margin to be produced even at a high-speed recording such as octupled speed recording. In addition, the recording quality may be improved through reduction in the recording jitter.
[0017] That is, with the present invention, recording with optimal pit shape may be achieved at a speed higher than the quadrupled speed, such as at an octupled or duodeca-tupled speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIGS. 1A and 1B show waveform diagrams showing recording strategies in mono-tupled speed recording and double speed recording as prescribed in the Orange-Book standard.
[0019] [0019]FIGS. 2A and 2B are waveform diagrams showing a recording strategy in quadrupled speed recording as prescribed in the Orange-Book standard.
[0020] [0020]FIGS. 3A and 3B illustrate an ideal recording state.
[0021] [0021]FIGS. 4A and 4B illustrate pit distortion in octupled speed recording using the recording strategies in mono-tupled speed recording and double speed recording.
[0022] [0022]FIGS. 5A and 5B illustrate pit distortion in octupled speed recording using the recording strategy in quadrupled speed recording.
[0023] [0023]FIG. 6 is a block diagram showing a structure of an optical disc recording and/or reproducing apparatus embodying the present invention.
[0024] [0024]FIG. 7 is a waveform diagram showing the recording strategy as used in the optical disc recording and/or reproducing apparatus shown in FIG. 6.
[0025] [0025]FIG. 8 is a block diagram showing a specified illustrative structure of a recording pulse generating circuit in the optical disc recording and/or reproducing apparatus shown in FIG. 6.
[0026] [0026]FIG. 9 is a waveform diagram showing the recording operation by the optical disc recording and/or reproducing apparatus shown in FIG. 6.
[0027] [0027]FIG. 10 is a graph showing measured results of replay 3T pit jitter characteristics obtained on octupled speed recording on a CD-R disc coated with a cyanine-based organic dyestuff.
[0028] [0028]FIG. 11 is a graph showing measured results of replay 3T land jitter characteristics obtained on octupled speed recording on a CD-R disc coated with a cyanine-based organic dyestuff.
[0029] [0029]FIG. 12 is a graph showing measured results of replay 3T pit jitter characteristics obtained on octupled speed recording on a CD-R disc coated with a phthalocyanine-based organic dyestuff.
[0030] [0030]FIG. 13 is a graph showing measured results of replay 3T land jitter characteristics obtained on octupled speed recording on a CD-R disc coated with a phthalocyanine-based organic dyestuff.
[0031] [0031]FIG. 14 is a waveform diagram showing a modification of a recording strategy as used in the optical disc recording and/or reproducing apparatus shown in FIG. 6.
[0032] [0032]FIG. 15 is a block diagram of a recording laser power controlling system embodying the present invention.
[0033] [0033]FIGS. 16A to 16 E illustrate recording laser patterns and driving pulses embodying the present invention.
[0034] FIGS. 17 to 22 illustrate typical recording laser patterns embodying the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Referring to the drawings, preferred embodiments of the present invention will be explained in detail.
[0036] The present invention is applied to an optical disc recording and/or reproducing apparatus 100 configured as shown for example in FIG. 6.
[0037] The optical disc recording and/or reproducing apparatus 100 , shown in FIG. 6, is a disc drive of the mark length recording system in which a CD-R (CD-Recordable), that is a write-once optical disc 1 , is run in rotation at a CLV by a spindle motor 2 , and in which the laser light is illuminated on the recording surface of the optical disc 1 by an optical head 3 to form pits to effect data recording and/or reproduction. The optical disc recording and/or reproducing apparatus 100 includes a servo circuit 4 , connected to the spindle motor 2 and to the optical head 3 , a recording pulse generating circuit 5 , connected to the optical head 3 , a replay signal processing circuit 6 , similarly connected to the optical head 3 , an encoder/decoder circuit 7 , connected to the recording pulse generating circuit 5 and to the replay signal processing circuit 6 , an SCSI interfacing circuit 8 , connected to the encoder/decoder circuit 7 , and a system controller 9 connected to the servo circuit 4 , encoder/decoder circuit 7 and to the SCSI interfacing circuit 8 , and is connected to an external host computer 10 through the SCSI interfacing circuit 8 .
[0038] The servo circuit 4 is controlled by the host computer 10 as to a control operation conforming to a control command supplied from the host computer 10 through the SCSI interfacing circuit 8 . The servo circuit 4 driving-controls the spindle motor 2 to cause the rotation of the optical disc at the CLV, so that, during data recording and/or reproduction, a target area on the recording surface of the optical disc 1 will be accessed by the optical head 3 . The servo circuit 4 also controls the optical head 3 as to its feed, focusing and tracking.
[0039] In this optical disc recording and/or reproducing apparatus 100 , data to be written is sent from the host computer 10 through the SCSI interfacing circuit 8 to the encoder/decoder circuit 7 where the data to be written is encoded into signals of the desired data format, for example, EFM signals, so as to be sent to the recording pulse generating circuit 5 .
[0040] The recording pulse generating circuit 5 in the optical disc recording and/or reproducing apparatus 100 performs recording strategy (recording compensation) processing on the EFM (eight-to-fourteen modulated) signals, supplied from the encoder/decoder circuit 7 , depending on dye materials of the recording medium, material type of the reflecting film, linear speed, or on recording speed characteristics of the optical system of the recording and/or reproducing apparatus, to generate recording pulses.
[0041] [0041]FIG. 7 shows typical recording pulses generated by the recording pulse generating circuit 5 .
[0042] In FIG. 7, the recording pulses ODT 1 and ODT 2 are variably set in the ranges of
OT≦ODT 1 ≦3.0 T, Pw* 0.0≦Δ P 1 ≦ Pw* 0.5
OT≦ODT 2 ≦3.0 T, Pw* 0.0≦Δ P 2 ≦ Pw* 0.5
[0043] within a recording pulse outputting period of 3T to 11T. It is noted that ODT 1 , ODT 2 , ΔP 1 and ΔP 2 are related to one another by
ODT 1 ≧ ODT 2
Δ P 1 ≧Δ P 2 .
[0044] Meanwhile, the outputting periods of the recording pulses ODT 1 and ODT 2 can be independently varied for each of the recording pulses 3T to 11T, if the relationship:
ODT 1 ( 3T )≧ ODT 1 ( 4T )≧. . . ODT 1 ( 11T )
ODT 2 ( 3T )≧ ODT 2 ( 4T )≧. . . ODT 2 ( 11T )
[0045] is maintained.
[0046] It is noted that, in recording on a recording medium, such as an optical disc, in accordance with the optical modulation recording system, the shorter the length of a land (space) lying directly ahead of the pit to be recorded, the more likely the thermal interference is produced, because the heat accumulated in recording the directly previous pit (mark) is not dissipated sufficiently. With the present recording pulse generating circuit 5 , the pulse lengths of the respective pulses can be variable optionally and independently by proper combinations of the pits (marks) and lands (spaces) to be recorded, thereby varying the recording pulse length such as to optimize the replay signal following the recording.
[0047] The recording pulses, generated by the recording pulse generating circuit 5 , are furnished to a laser diver circuit 30 for laser driving, enclosed in the optical head 3 . The laser diode is driven by the laser diver circuit 30 in accordance with the logic of the recording pulses to cause the laser diode to emit light to record data on the optical disc 1 .
[0048] The recording pulse generating circuit 5 for superposing two-step stacking portions ΔP 1 , ΔP 2 at approximately the leading end of an EQEFM recording pulse V 1 by the recording strategy processing to generate the recording pulse V 1 includes a pit/land length detection circuit 51 , an EQEFM generating circuit 52 , an ODP 1 generating circuit 53 and an ODP 2 generating circuit 54 , as shown for example in FIG. 8.
[0049] In this recording pulse generating circuit 5 , the pit/land length detection circuit 51 detects the pulse width of the EFM signal sent from the encoder/decoder circuit 7 and directly previous pit and land lengths. The EQEFM generating circuit 52 generates an EQEFM recording pulse V 1 of a pre-set level and pulse width derived from the EFM signal, while the ODP 1 generating circuit 53 generates an ODP 1 recording pulse V 2 to be added to approximately the leading end of the laser driving pulse and the ODP 2 generating circuit 54 generates an ODP 2 recording pulse V 3 to be added to approximately the leading end of the laser driving pulse. The recording pulses V 1 , V 2 , V 3 , generated by the EQEFM generating circuit 52 , ODP 1 generating circuit 53 and the ODP 2 generating circuit 54 , respectively, are variably controlled as to the pulse widths or pulse levels (voltage levels) depending on the pulse width of the EFM signal detected by the pit/land length detection circuit 51 or on directly previous pit lengths or land lengths.
[0050] It is noted that switches SW 1 , SW 2 and SW 3 are changeover circuits for enabling/disabling the recording pulses, ODP recording pulses V 2 and ODP recording pulses V 3 , respectively, and are controlled by the system controller 9 .
[0051] That is, the system controller 9 is responsive to the write command and the mode setting command sent from the host computer 10 to recognize with which multiple speed the recording data transferred from the host computer 10 is to be recorded on the disc. The switches SW 1 , SW 2 and SW 3 are changed over responsive to the write speed as required. For example, if the write speed is mono-tupled or double speed, the switches SW 2 and SW 3 are turned off to disable the ODP 1 generating circuit 53 and the ODP 2 generating circuit 54 so that ODP recording pulses V 2 or ODP recording pulses V 3 are not added as the recording pulse as shown in FIG. 1. If the write speed required is the quadrupled speed, only the switch SW 3 is turned off so as not to permit the ODP recording pulse V 3 to be added as the recording pulse shown in FIG. 2. In recording data with the octupled speed or duo-deca-tupled speed, as in the present invention, the switches SW 1 , SW 2 and SW 3 are all turned on to permit the recording pulse shown in FIG. 7 to be output.
[0052] The recording pulses V 1 to V 3 , generated in the recording pulse generating circuit 5 , are sent to the laser diver circuit 30 enclosed in the optical head 3 . The laser diode LD is driven by the laser diver circuit 30 in accordance with the logic of each recording pulse to cause the recording laser to emit light to record data on the optical disc 1 . In the laser diver circuit 30 , the recording pulses V 1 to V 3 , generated by the ODP 1 generating circuit 52 , ODP 1 generating circuit 53 and the ODP 2 generating circuit 54 , are converted by current/voltage converting circuits 31 to 33 into recording current signals I1 to I3, respectively, which are summed and synthesized together by an addition circuit 34 to generate a driving current i (=I1+I2+I3) which then is caused to flow through the laser diode LD to drive the laser diode LD to cause the recording laser to emit light to record data on the optical disc 1 .
[0053] That is, in this recording pulse generating circuit 5 , the driving current i, obtained on summing the recording pulses V 1 to V 3 , generated in the recording pulse generating circuit 5 , as current values, is caused to flow through the laser diode LD, and the recording laser of the light emission waveform having two-step stacked portions ΔP 1 and ΔP 2 in approximately the leading edge of the EQEFM signal is illuminated from the laser diode LD on the recording surface of the optical disc 1 , as shown in FIG. 9, to form a track comprised of a pit and a land on the recording surface.
[0054] In FIG. 9, the time period C indicates the time delay since the turning on of the laser light emission until a pit starts to be formed, while the time period c indicates the time delay since the turning off of the laser light emission until the pit has been formed. The time periods C and c may be represented by
[0055] C<B<A and
[0056] c<b<a,
[0057] where the time periods A and a are time periods in case recording is made using the recording strategy for mono-tupled and double speed recording, as shown in FIG. 4, and the time periods B and b are the time periods in case recording is made using the recording strategy for quadrupled speed recording, as shown in FIG. 5. That is, the above time period C and c are shorter than the time periods A and a or B and b.
[0058] Thus, with the optical disc recording and/or reproducing apparatus 100 according to the present invention, pits/lands can be produced which are adapted more accurately to the EFM signals in high-speed recording.
[0059] In this optical disc recording and/or reproducing apparatus 100 , in which the driving current i is generated by summing the ODP recording pulse V 2 and ODP recording pulse V 3 to the EQEFM recording pulse V 1 , the levels or the pulse widths of the pulses V 1 to V 3 are varied depending on the recording conditions, or on pulse widths of the EFM signals detected by the pit/land length detection circuit 51 or directly previous pit or land length, with the pulse length being optionally and independently set responsive to each of the durations of 3T to 11T.
[0060] In actuality, the pulse width or the pulse level is adjusted depending on such conditions as the disc material type (type of the dye film material), disc makers, recording linear velocity or optical properties of the optical head.
[0061] In particular, in view of difference in the thermal reaction caused by the difference in the type of the dye material, it is effective to check for the type of the disc loaded in recording or the disc producer to adjust the pulse width or level. It is similarly effective for the recording operation to adjust the pulse width or level after the start of the recording.
[0062] Of the cyanine-based or phthalocyanine-based disc, characteristics of the replay 3T pit/land jitter were measured, and the results shown in FIGS. 10 to 13 were obtained.
[0063] [0063]FIGS. 10 and 11 show measured results of replay 3T pit jitter characteristics and replay 3T land jitter characteristics, obtained on octupled speed recording on a CD-R medium coated with the cyanine-based organic dye. FIGS. 12 and 13 show measured results of replay 3T pit jitter characteristics and replay 3T land jitter characteristics, obtained on octupled speed recording on a CD-R medium coated with the phthalocyanine-based organic dye. In FIGS. 10 to 13 , the abscissa and the ordinate denote the recording power and the RF jitter contained in the replay RF signals.
[0064] In FIGS. 10 to 13 , the measured results in case recording is effected for θ=0.25, α=0.13T, using the recording strategy for conventional mono-tupled and double speed recording shown in FIG. 1, those in case recording is effected for θ=0.25, α=1.50T and ΔP=30%, using the recording strategy for conventional quadrupled speed recording shown in FIG. 2, and those in case recording is effected on the optical disc recording and/or reproducing apparatus 100 of the present invention with the optimized pulse lengths of the respective recording pulses, are indicated by ▪, ▴ and , respectively.
[0065] As may be seen from the measured results of the replay 3T pit/land jitter characteristics, shown in FIGS. 10 to 13 , the post-recording pit/land jitter is improved significantly, without regard to the type of the organic dye material or the recording medium used, whilst the lowering in the power margin of the jitter with respect to the recording power or in the recording power may be prohibited appreciably.
[0066] In the above-described optical disc recording and/or reproducing apparatus 100 , the recording laser light comprised of the EQEFM recording pulse V 1 , on approximately the leading edge of which ΔP 1 and ΔP 2 are stacked, is adapted to emit light. Alternatively, such a recording strategy may also be used in which the recording pulse generating circuit 5 generates the EQEFM recording pulse V 1 and m sorts of ODP 1 recording pulses, namely the ODP 1 recording pulse V 1 to ODPm recording pulse Vm, with pulse widths of L 1 to Lm, to cause the recording laser of a waveform having the m-stage stacked portions ΔP 1 to ΔPm at approximately the forward end of the EQEFM recording pulse V 1 to emit light to effect recording, as shown in FIG. 14.
[0067] The components of a modified embodiment of a disc drive device responsible for generating laser driving pulses at the time of recording are extracted and shown in FIG. 15. Meanwhile, the overall structure of the disc drive device is similar to that of the first embodiment shown in FIG. 1.
[0068] During recording, the EFM signals from the encoder/decoder circuit 7 are sent to a recording pulse generator 121 which is made up of a pit/land length detection circuit 131 , an end pulse generating circuit 132 , a first pulse generating circuit 133 and an EQEFM generating circuit 134 .
[0069] The EQEFM generating circuit 134 generates an EQEFM signal V 11 of a preset level and a pulse width derived from the EFM signal.
[0070] The first pulse generating circuit 133 generates a first over-drive pulse V 21 to be added to approximately the leading end of a laser driving pulse.
[0071] The end pulse generating circuit 132 generates an end over-drive pulse V 31 to be added to approximately the trailing end of the laser driving pulse.
[0072] The end pulse generating circuit 132 , first pulse generating circuit 133 and the EQEFM generating circuit 134 generate respective pulses V 11 , V 21 and V 31 with pulse. widths corresponding to the pulse width of the EFM signal. The pulse width or the pulse level (voltage level) is variably controlled depending on the current pulse width or the directly previous pit or land length of the EFM signal as detected by the pit/land length detection circuit.
[0073] The switches SW 1 , SW 2 and SW 3 are changeover circuits for enabling/disabling the EQEFM signal V 11 , first over-drive pulse V 21 and the end over-drive pulse V 31 , and are controlled by the system controller 9 . That is, the system controller 9 is responsive to the write command or the mode setting command sent from the host computer 10 to recognize with which multiple speed the recording data transferred from the host computer 10 is to be recorded on the disc. The system controller 9 changes over the switches SW 1 to SW 3 depending on the write speed as required. For example, if the write speed is the mono-tupled or double speed, the system controller 9 disables the first pulse generating circuit 133 and the end pulse generating circuit 132 by turning the switches SW 2 and SW 3 off so as to preclude the appendage of the first over-drive pulse V 21 and the end over-drive pulse V 31 , as indicated by the drive pulse shown in FIG. 1. If the write speed as requested is the quadrupled speed, only the switch SW 3 is turned off to preclude the outputting of the end over-drive pulse V 31 as indicated by the drive pulse shown in FIG. 2. In recording the data at an octupled speed, as newly proposed in accordance with the present invention, all of the switches SW 1 , SW 2 and SW 3 are turned on to output a drive pulse as indicated in FIGS. 17 to 22 .
[0074] The EQEFM signal V 11 , first over-drive pulse V 21 and the end over-drive pulse V 31 are converted respectively into current signals i 11 , i 21 and i 31 in the current/voltage converting circuits 137 , 136 , 135 in laser diver circuit 30 .
[0075] In the addition circuit 138 , the current signals i 17 , i 27 and i 37 are added to give the driving current i applied to the laser diode LD.
[0076] Meanwhile, in the present embodiment, control signals from the system controller 9 are input to the voltage/current converting circuits 137 , 136 , 135 . That is, if the level (amplitude) of each pulse is to be changed depending on e.g., the rotational speed of the disc (linear speed relative to the track) during recording, length of the pit recorded, the material type of the recording layer (dye layer) used in the disc, or ambient temperature, control signals or parameters are input by the system controller 9 . Thus, the level (amplitude) of the respective signals V 11 , V 21 , V 31 is individually controlled by parameters applied to the voltage/current converting circuits 137 , 136 , 135 . Although the voltage/current converting circuits 137 , 136 , 135 are provided in the present embodiment with the level adjustment function, it is also possible to provide a level adjustment circuit upstream or downstream of the voltage/current converting circuits 137 , 136 , 135 as a separate circuit.
[0077] The laser power controlled in the present stricture is as follows:
[0078] [0078]FIGS. 16C, 16D and 16 E show specified examples of the end over-drive pulse (ODP END; V 31 ), first over-drive pulse (ODP FIRST; V 21 ) and EQEFM signal V 11 , respectively.
[0079] The laser power output by the driving current i, corresponding to the current values rendered from the signals V 11 , V 21 and V 31 and summed together, is as shown in FIG. 16A. That is, the power by the first over-drive pulse is summed to the leading end of the EQEFM signal, whilst the power by the over-drive pulse is summed to the trailing end. It is noted that Pr, Pw and Pod are the replay laser level, recording laser level and the laser level by the over-drive pulse, respectively.
[0080] By the output laser power of the laser diode LD being controlled in this manner, a track by the pit P and the land L is formed on the disc 1 , as shown in FIG. 16B.
[0081] In FIG. 16, the time period C denotes the time delay as from the turning on of the laser light emission until the pit P starts to be formed, whilst the time period c denotes the time delay as from the turning off of the laser light emission until the end of forming of the pit P.
[0082] These time periods C and c are shorter than the time periods A, B, a and b shown in FIG. 5, meaning that, in the present embodiment the pits/lands coping accurately with the EFM signals can be formed even in recording at a high speed.
[0083] In the present embodiment, the end over-drive pulse and the first over-drive pulse are summed to the EQEFM signals to generate the driving signal i. The EQEFM signals end over-drive pulse and the first over-drive pulse, generated by the recording signal generating unit 121 , can be varied in level or pulse width depending on the pit or land length of the fore and aft side pits and lands as detected by the pit/land length detection circuit. The system controller 9 optionally variably sets the pulse width depending on the different pulses 3T to 11T.
[0084] That is, the pulse width is basically the pulse of (N−X(N))T pulse for the N(T) EFM pulse.
[0085] That is, the values X3 to X11 for setting the pulse widths of the EQEFM signal are optionally respectively set depending on the respective pulses of 3T to 11T.
[0086] For example, FIG. 16A is associated with the EFM signals of FIG. 3A, whereas EQEFM signal with the pulse width of (3−X3)T pulse width is generated during the 3T pulse period of the EFM signals. Also, during the 11T pulse period, the EQEFM signal with the pulse width of (11−X11)T is generated.
[0087] That is, the pulse width is controlled in accordance with the different in the pulse width, that is the difference in the heat storage on the recording track caused by the difference in the laser illuminating time period, thus enabling the pits/lands suitably conforming to the EFM signals.
[0088] By way of an example, the values of X3 to X11 may take on the values of 0.25 to 0.2.
[0089] To the EQEFM signal are summed the first over-drive pulse and the end over-drive pulse. As the synthesized waveform pattern (laser output level control pattern), a variety of patterns as shown for example in FIGS. 17 to 22 may be used. In FIGS. 17 to 22 , L 1 and L 2 denote pulse widths of the first over-drive pulse an the end over-drive pulse, respectively.
[0090] [0090]FIG. 17 shows a case in which L 1 -L 2 and in which the rising of the first over-drive pulse and the decay of the EQEFM signal are synchronized with the EQEFM signal.
[0091] [0091]FIG. 18 shows a case in which L 1 <L 2 and in which the rising of the first over-drive pulse and the decay of the EQEFM signal are synchronized with the EQEFM signal.
[0092] [0092]FIG. 19 shows a case in which L 1 >L 2 and in which the rising of the first over-drive pulse and the decay of the EQEFM signal are synchronized with the EQEFM signal.
[0093] [0093]FIG. 20 shows a case in which L 1 =L 2 and in which the rising of the first over-drive pulse is earlier than the EQEFM signal and the decay of the end over-drive pulse is later than the EQEFM signal.
[0094] [0094]FIG. 21 shows a case in which L 1 <L 2 and in which the rising of the first over-drive pulse is synchronized with the EQEFM signal and the decay of the end over-drive pulse is later than the EQEFM signal.
[0095] [0095]FIG. 22 shows a case in which L 1 >L 2 and in which the rising of the first over-drive pulse is earlier than the EQEFM signal and the decay of the end over-drive pulse is synchronized with the EQEFM signal.
[0096] In all of these figures, it is possible to realize a laser light emission pattern as indicated as an LD light output.
[0097] Other patterns than these may, of course, be realized.
[0098] The respective patterns may be selectively used, in particular the time periods L 1 and L 2 may be set, depending on the pit and land lengths directly before and after detection by the pit/land length detection circuit. For example, if the directly previous land domain is longer, the time period L 1 is longer, whereas, if the directly previous land domain is shorter, the time period L 1 is shorter.
[0099] That is, the laser driving pattern is controlled depending on variations in the heat storage caused by different pit/land lengths.
[0100] The lengths of the time periods L 1 and L 2 are variable in a range from 0T to 3T.
[0101] Although not shown, the levels (voltage values) of the end over-drive pulse and the first over-drive pulse may be varied depending on the lengths of the fore and aft side pit and land, as in L 1 and L 2 above.
[0102] That is, the heat quantity stored in the disc 1 is determined on the basis of both the laser light volume and the time period, such that optimum laser drive pattern may be set depending on the variations of the heat storage quantity by the pit length/land length.
[0103] For example, the level Pod in FIG. 16 is changed between e.g., a 20%-up value, 25%-up value and a 30%-up value of the recording laser power Pw.
[0104] So, when a CD-R as the disc 1 is run in rotation at an octupled speed for data recording, the parameters given in generating the respective pulses are hereinafter explained, taking a waveform pattern shown in FIG. 19 as an example.
[0105] With the EQEFM signal having a pulse width of (N−0.25)T, the first over-drive pulse and the end over-drive pulse, added to the EQEFM signal, are of pulse widths L 1 and L 2 equal to 1.75T and 1T, respectively, if the length of the lands formed directly ahead and at back is 8T. These pulses are of a level (amplitude) larger by approximately 30% than the level of the EQEFM signal. Meanwhile, the pulse width of the first over-drive pulse is varied, as the system controller 9 sets parameters for the recording signal generator 121 , depending on the length of the pit to be recorded (3T to 11T) or the length of the land (3T to 11T) formed directly before and after the pit. That is, there are a sum total of 729 parameters corresponding to different combinations of nine directly previous land lengths, nine recording pit lengths and nine directly following land lengths. For example, L 1 =1.75T is set to 1.05T and to 0.35T if the recording pit length is 4T and in a range of 5T to 11T, respectively. In addition, −0.2T to +0.2T is added to these values depending on the directly previous land lengths. For example, if L 1 =1.75T is a reference value, Li is set to a value from 1.55T to 1.95T.
[0106] In actuality, the pulse width and the pulse level are also adjusted depending on the type of the disc material (that of the dye film material), disc producer, recording linear speed, recording speed or characteristics of the optical system of the optical pickup 1 .
[0107] Moreover, since the difference in the thermal reaction is caused by e.g., the difference in the type of the dye film material, it is effective to discriminate the sort of the disc loaded or the maker at the time of recording to adjust the pulse width or the pulse level. The execution environment during recording, such as the recording linear speed or the recording speed, may be transmitted by e.g., the system controller 9 to the recording pulse generator 121 to adjust the pulse width or the pulse level for optimal recording.
[0108] Thus, by controlling the laser light emission by the driving current i corresponding to the sum of the EQEFM signal to the end over-drive pulse and to the first over-drive pulse as shown in FIG. 16A, by varying the level or the pulse width of the EQEFM signal, end over-drive pulse and the first over-drive pulse in the recording pulse generator 121 depending on recording conditions or on the lengths of fore and aft side pits and lands and by optionally variably setting the pulse width depending on different durations of 3T to 11T. The first and second embodiments of the present invention may also be applied in combination. | A method for recording on a write-once type optical disc. A laser light beam excited to light emission by a recording pulse having a pulse width corresponding to the length of a pit formed, with the recording power of substantially the leading end o the pulse being stepped over plural stages, is illuminated on a write-once type optical disc for recording. This enables recording with an optimal pit shape at a speed faster than a quadrupled speed, such as at an octupled speed or a duo-deca-tupled speed. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a clamp for releasably engaging struts and temporarily supporting pipes adjacent thereto until a permanent connection can be made.
2. Description of the Related Art
In construction of buildings struts are used to hold pipes, electrical conduit and other objects. For example, installing a long, heavy length of pipe to struts hanging from the ceiling currently takes two people, one at each end of the pipe. One person will hold the pipe on one end and the other person will connect the pipe to the previous section and make a permanent connection to the strut. The second person can then connect his end of the pipe to the strut. Typically these pipes are attached to the ceiling or a wall thus requiring two ladders or lifts and the coordinated movements of two people. If one end of the pipe is dropped it can be dangerous and can damage objects below. It is desired to have a device which will temporarily hold a pipe adjacent a strut in a secure manner to eliminate the need for a second person during installation of the pipe. It is further desired to have a simple tool for aligning the pitch of the pipes.
SUMMARY OF THE INVENTION
A clamp for attachment to struts is provided wherein two opposing jaws are drawn together and locked into position on the lips of the strut. The clamp has attachments for holding pipes or other devices needed for construction.
The clamp allows one person to do the job of two people by holding one end of a pipe adjacent a strut while the other end is being worked on. The clamp improves the safety of the handling of the pipes, while saving time by making it quicker to install pipe. The clamp can be used in all positions, be installed with one hand, will lock in place and stay tight. The clamp has adjustable pinch strength and can be used on horizontal or vertical installations. The clamp has a fixed jaw and a movable jaw, which engages and holds the lip of a strut. A handle on the clamp pulls the jaws together and locks them into place to fix the clamp to the struts. Attachments to the clamp hold pipes or other objects in place while being connected to the struts allowing one man to do the work of two or more men.
Attachments to the clamp allow for holding pipes or other objects until they are permanently attached to the struts. Other attachments to the clamp are used for leveling or pitching the pipes. A laser attached to a clamp can provide a site line for pipes or for positioning of struts. A trapeze strut can be adjusted on its rods for height by use of a laser for sighting pitch of the strut locations for pipes to rest on the struts.
OBJECTS OF THE INVENTION
It is an object of the invention to safely yet temporarily attach pipes to struts during the permanent installation process.
It is an object of the invention to hold pipes level for level installation.
It is an object of the invention to hold pipes at predetermined angles for pitched installation.
It is an object of the invention to provide the clamp with accessories for use in hanging objects from struts.
It is an object of the invention to provide the clamp with accessories for aligning or angling two struts for connection.
It is an object of the invention to allow one person to hang pipe from struts.
It is an object of the invention to allow quick and easy leveling of the strut hangers themselves.
It is an object of the invention to quickly and easily attach the clamp to a strut.
It is an object of the invention to quickly and easily remove the clamp from a strut.
It is an object of the invention to provide the clamp various easy to attach accessories allowing multiple uses for the clamp.
Other objects, advantages and novel features of the present invention will become apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the clamp on a strut ready to receive a pipe, conduit or other products.
FIG. 2 is a top view of a portion of the clamp engaging a strut with the jaws in a closed position.
FIG. 3 is a side schematic view of the clamp.
FIG. 4 is a side perspective view of the clamp.
FIG. 5 is a top cross section view of the tension pin engaging the main actuating arm and the jaws extended to the open position.
FIG. 6 is a side view of the clamp with a pipe holding attachment.
FIG. 7 is a top view of the clamp with a pipe holding attachment.
FIG. 8 is a side view of a pipe holding attachment.
FIG. 9 is a bottom perspective view of the clamp with an attachment arm integral with the housing.
FIG. 10 shows a clamp housing with posts for engaging pipes therebetween.
FIG. 11 shows a laser attachment on a clamp for sighting the pitch of pipes on a trapeze strut.
FIG. 12 shows a laser attachment on a clamp for sighting the pitch for pipes with struts attached to a wall or ceiling.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In construction projects gas pipes, water pipes, compressed air pipes, ducting, electrical conduit, fire sprinklers, hoses, cables, struts, supports, and other items are connected to or held by struts. The struts may be vertical or horizontal. Long heavy length of pipe generally require a two man crew to install the pipe, one to hold one end of the pipe and the other to hold the other end and attach it to an adjoining pipe and or secure it to a strut. Struts have a standardized shape the cross section of which can be seen in FIG. 1 .
FIG. 1 shows a clamp 10 attached to a vertical strut 80 secured to a wall, for holding pipes horizontally along the wall 400 . A pipe holding attachment 40 on clamp 10 defines a square bounded by the clamp 10 on the bottom, the pipe holding attachment 40 on the top and one side and the strut 80 on the other side into which a pipe may be held, such that the pipe cannot escape the area. In this manner the pipe may be held in place on one end, rather than have an assistant hold it, while being connected to another pipe and/or secured to a strut on the other end. Similarly the clamp, used in pairs can hold both ends of a pipe to make it easier to work on the pipe for connection to other pipes or securing the pipe to a strut.
Although pipes are used herein as the object held by the clamp electrical conduit or any other object can be held by this device.
FIG. 2 shows the means of engaging the clamp 10 to strut 80 . Struts 80 such as those made by Unistrut®, B-Line® and other manufacturers, have a C shapes with lips 82 curved inward at each end. Clamp 10 has a fixed jaw 60 and a moveable jaw 62 for engaging the lip 82 of the strut 80 . In an alternative embodiment moveable jaw 62 has lip portion 162 for wrapping around the lip 82 of the strut 80 for a better grip and stronger hold.
Fixed jaw 60 and moveable jaw 62 can have a roughened or textured surfaces 260 and 262 respectively to obtain a better grip on and hold the lips 82 on struts 80 .
The moveable jaws 62 are optionally biased by spring 126 to be pulled toward one another when not engaging strut 80 to better insert the moveable jaws 62 into or extract them from the strut 80 . As shown when the movable jaws 62 are drawn toward fixed jaws 60 the ramped portion 170 engages spreader pin 25 and moves the moveable jaws 62 apart as they transition from the thin portion 172 to the thick portion 174 . Thus as the movable jaws 62 are pulled toward the fixed jaws 60 they are pushed apart to engage the lips 82 of the strut 80 . Note that the inside width of the clamp housing 20 equals the width of the spreader pin 25 and the thick portion 174 of the moveable jaw arms 64 on movable jaw 62 .
The mechanics of tightening the clamp 10 are shown in FIG. 3 . The clamp can be adjusted to tighten on any size strut 80 by turning adjustment screw 14 . Adjustment screw 14 limits the travel of foot 15 in housing 20 and thereby fixes the position of maximum travel of jaw 62 and sets the pinch strength of the clamp 10 . Foot 15 is pivotally connected at point 38 to swing arm 17 , which is pivotally connected at point 30 to cam 18 on handle 12 . Swing arm 17 passes thought slot 22 (see FIG. 9) in housing 20 to connect to pivot point 38 on foot 15 . Handle 12 is pivotally connected at point 32 , to actuating arm 68 which rotates on pivot point 34 , on housing arm 28 . The actuating arm 68 passes through slot 22 in housing 20 and is pivotally connected, at pivot point 36 , to movable jaw arm 64 in housing 20 for locking the movable jaw 62 in place relative to fixed jaw 60 . The actuating arm 68 is shown curved, but it could be straight, such that as the handle 12 is pulled toward the housing 20 it passes a locking point when pivot point 32 is aligned with pivot point 30 . At that point, pivot point 30 goes past the straight line between pivot points 32 and 38 . The handle 12 then cams over center in the arc it swings thorough and the last part of the handles' stroke is devoted to locking the handle 12 in place. The handle stop 16 is adjustable to limit the movement of the handle 12 toward the housing 20 . The handle 12 is shown as being straight but it may be curved or angled.
The actuating arm 68 is pivotally connected to the moveable jaw arms 64 by floating tension pin 36 . As best seen in FIG. 5 the actuating arm 68 preferably has a curved surface for engaging the tension pin 36 allowing the tension pin to rock such that the moveable jaw arms 64 can independently engage the strut 80 while the moveable jaws 62 are being pulled backwards toward fixed jaws 60 .
As best seen in FIG. 2 showing the jaws 60 , 62 in a locked position on strut 80 the moveable jaw arms 64 preferably have a straight narrow section 172 , a curved section 170 , and a straight thick section 174 . The difference in thicknesses on the length of the moveable jaw arms 64 are for adjusting the width of the moveable jaws for engaging the struts 80 . When the jaws 62 are not engaging the struts 80 they are able to move toward each other for entering or exiting the strut. The jaw arms 64 on either side of the spreader pin 25 are in the narrow portion 172 during this phase of operation as shown in FIG. 5 . As the moveable jaw arms 64 are retracted by handle 12 the spreader pin 25 engages the curved section 170 pushing the moveable jaw arms 64 apart until the thick portion 174 is reached which maximizes the spreading of the moveable jaw arms 64 . The thick portion 174 of moveable jaw arms 64 plus the spreader pin 25 approximates the width of the inside of the housing 20 . The jaws 62 are spread apart to engage the strut lip 82 when the spreader pin 25 is adjacent the thick portion 174 of moveable jaw arms 64 . A spring 126 can be used to pull the moveable jaw arms together when spreader pin 25 is adjacent the narrow portion 172 of moveable jaw arms 64 .
The moveable jaw arms 64 have jaws 62 for engaging the lips 82 of strut 80 . Alternatively the moveable jaw arms 64 may have a lip 162 for hooking over the lips 82 of the strut for a more secure connection. Further, roughened surface area 260 on fixed jaw 60 can enhance the grip of the jaws 60 , 62 on strut 80 .
Return spring 50 extends between the actuating arm 68 and the spreader pin 25 to bias the handle 12 in the unlocked position with the narrow portion 174 of moveable jaw arms 64 adjacent spreader pin 25 for ease of inserting or extracting the jaws 62 into the strut 80 .
Many types of attachments may be used on the housing 20 . As best seen in FIG. 8, 6 , 1 and 4 a pipe holding attachment 40 , 140 may be bolted at apertures 43 , 45 , 143 , 145 to the housing 20 . A pipe may be inserted into the area bordered by strut 80 , housing 20 and attachment 40 , 140 . Attachment 40 , 140 may be a variety of shapes including C shaped or L shaped. When attachment 40 is C shaped as in FIG. 4, it forms a square with sides 44 , 42 , 46 on C shaped attachment 40 and the strut 80 , to insert pipes into as shown in FIG. 1 and 6. When an L shaped attachment is used the top portion is open making it easier to insert the pipes as shown in FIG. 8 . Alternatively an L shaped attachment 140 , having apertures 143 and 145 for connecting the attachment to the housing 20 of clamp 10 , has an arm 142 perpendicular to the housing 20 . A pipe 100 can rest between the strut 80 and arm 142 on the base portion 141 of L shaped attachment 140 . A spring loaded swing arm 145 on the L shaped attachment 140 allows a pipe to enter the attachment from the top by depressing the swing arm 145 . Swing arm 145 will then allow a pipe to be captured as in the C shaped attachment 40 . When swing arm 145 is swung downward to admit pipe 100 , spring 144 will pull the swing arm 145 back to engage pin 149 leaving swing arm 145 in a position perpendicular to arm 142 and preventing pipe 100 from being removed from the capture area.
Although bolts through apertures 143 and 145 can hold attachment 140 in place along the side of the clamp housing 20 other methods of placing attachments on the housing may be used. The attachment points may also be varied on the housing 20 . For example the attachment point can be on the top, or either side, or other location, of the housing 20 and be permanently or removeably attached. As shown in FIG. 9 attachment 40 may be integral with housing 20 .
FIG. 10 shows an alternative for positioning pipes relative to the housing 20 . One or more posts 500 can be attached to the housing 40 such as by insertion into apertures 510 shown on the top of housing 40 or by posts 500 on pads 520 sliding in tracks 530 and locked into position by position lock 540 . Pipes can be held in position either between adjacent posts 500 or between a post 500 and the strut 80 or between a post and an attachment 40 , 140 .
Other attachments for use with the clamp 10 such as a laser for leveling or angling (pitching) the pipes can be used. Therefore when it is desired to (pitch) angle a drain pipe for better drainage the attachment may be used to sight the angle.
For positioning pipes a laser attached to one clamp can be used to set the position of other clamps. The clamps once attached can then have the pipes held in the correct position for level or (pitched) angled piped.
For example in FIG. 11 a series of trapeze struts 300 are used to hold pipes 330 from a ceiling. The trapeze struts 300 have threaded rods 310 attached to a ceiling and are adjustably connected to struts 320 by nuts 315 . By adjusting the nuts 315 on the threaded rods 310 the struts 320 may be moved upward or downward on the threaded rods 310 .
A clamp 10 having a laser 340 attached to the housing 20 , is connected to strut 320 and laser beam 345 having an adjustable pitch is used for sighting the position of the next strut 321 . The pitch adjustment of the laser 340 can be used to adjust the second strut 321 to be level with or pitched up or down from the first strut 320 . The second strut 321 may have a clamp 10 with a target attachment 350 having gradient lines 360 thereon for adjusting the pitch of the second strut 321 relative to the first strut 320 .
Similarly in FIG. 12 the struts 410 and 411 are attached to a wall 400 . Clamps 10 with laser attachment 340 and target attachment 350 are used on the struts to position the pipes 430 being attached to the wall 400 . Clamps 10 are moved to positions for supporting the pipes 430 at the desired pitch and the pipes are then rested on the clamps 10 and then attached to the struts 410 and 411 .
Another attachment can be used for making angles connections between struts. A clamp at the end of one strut can hold a connector for two struts for assembling the struts either straight or at angles.
The struts 80 may be used horizontally or vertically along walls or ceilings in conjunction with the clamp 10 .
The clamp 10 may be made in various sizes to fit the sizes of the struts 80 they are to engage.
The clamps 10 can be used with pipe piers having a cross section with lips similar to struts 80 for the clamp jaws 60 , 62 to engage. Thus pipes 100 on pipe piers can be held in place in with clamps 10 and aligned using laser attachments 340 in the same manner as with struts 80 . Pipe piers are commonly used in the building industry for holding pipes on rooftops and in above ground installations.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A tool for clamping onto a strut for holding objects such as pipes in place while they are being attached to the struts is disclosed. The clamp has opposing jaws, which are drawn together by movement of a handle, for pinching the lips of the strut and holding firmly thereto while holding objects adjacent the clamp. A handle on the clamp locks into a pinching position and can be released by opposite motion of the handle. Various attachments to the clamp housing can be used for holding different objects. The clamp has adjustable jaw positions for adjustable pinch strengths. The jaws are biased together when not engaging the strut to allow easy access to the strut for engaging the strut lips or removing the clamp from the strut. Use of the clamp allows one man to install pipes faster safer and easier and without the aid of a helper. | 8 |
BACKGROUND OF THE INVENTION
Lancing devices are typically handheld units that permit users to draw blood for testing and diagnostic purposes. These devices include a housing with a piercing aperture, a lancet that contains one or more needles, and a firing mechanism. The firing mechanism typically includes a spring or other biasing means which can be cocked either by insertion of the lancet or by movement of a cocking member. Once the lancing device is cocked, it is placed against the user's skin, often the fingertip. The user can then press a trigger to actuate the firing mechanism, which momentarily drives the sharp tip of the needle through the piercing aperture to puncture the user's skin and draw blood.
A myriad of lancing devices have been proposed and/or commercialized. Whereas these devices are generally satisfactory, the cocking mechanism tends to be rather complex and expensive and the devices do not provide a storage facility to store the lancets prior to use.
SUMMARY OF THE INVENTION
Embodiments disclosed herein concern a lancing device of the type including an elongated housing; a lancet holder receiving the lancet and mounted for axial movement in the housing between a retracted position and operative position and a cocked position; a cocking mechanism operative to move the lancet holder from its retracted position to its cocked position; and a trigger mounted on the housing and operative to release the lancet holder for movement from the cocked position to the operative position.
In accordance with some embodiments of the invention, a lancing device is disclosed comprising an elongated housing, a lancet, a lancet holder receiving the lancet and configured to move axially in the housing between a retracted position, an extended position, and a cocked position, and a cocking mechanism mounted on the housing and configured to move first inward relative to the housing and subsequently outward relative to the housing. The lancet holder is further configured to move from its retracted position to its cocked position in response to the outward movement of the cocking mechanism. The device also comprises a trigger mounted on the housing and operative to release the lancet holder for movement from the cocked position to the extended position.
In accordance with other embodiments of the invention, a lancing device is disclosed comprising a lancet, a lancet holder configured to receive the lancet and mounted for axial movement in the housing between a retracted position, an extended position, and a cocked position, a lancet storage compartment defined within the housing and sized to accommodate a plurality of lancets, a door configured to move between an open position allowing access to the storage compartment and a closed position preventing access to the storage compartment, a cocking mechanism engaged with the door and configured to move the lancet holder from its retracted position to its cocked position when the door is moved from the open position to the closed position and a trigger mounted on the housing and configured to release the lancet holder to move from the cocked position to the extended position.
In accordance with yet other embodiments of the invention, a method of cocking a lancing device is disclosed. The method, for use with a housing having a lancet holder disposed therein and a storage compartment to accommodate a plurality of lancets, comprises opening a door of the storage compartment to remove or deposit one or more of the plurality of lancets, and closing the door of the storage compartment to cock the lancing device, wherein closing the door of the storage compartment moves the lancet holder from a neutral position to a cocked position.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 is a perspective view of a lancing device according to a first embodiment of the invention;
FIGS. 2 , 3 , 4 , 5 and 6 are schematic cross-sectional views of the lancing device of FIG. 1 showing successive steps in the usage of the invention lancing device;
FIG. 7 is an exploded perspective view showing a cocking mechanism, a lancet holder, and a trigger employed in the FIG. 1 embodiment;
FIG. 8 is a perspective view of a second embodiment of the invention;
FIG. 9 is a somewhat schematic longitudinal cross-sectional view of the lancing device of FIG. 8 ;
FIG. 10 is a somewhat schematic cross-sectional view taken on line 10 - 10 of FIG. 9 ;
FIG. 11 is a perspective view of a third embodiment of the invention; and
FIG. 12 is a somewhat schematic cross-sectional view of the lancing device of FIG. 11 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The lancing device 10 seen in FIGS. 1-7 embodiment, broadly considered, includes a housing 12 , a lancet 16 , a lancet holder 18 , a cocking mechanism 20 and a trigger mechanism 22 .
Housing 10 includes a main body housing member 24 and a front cap 26 .
Main body housing member 24 is elongated, has a generally rectangular cross-sectional configuration, and includes a top wall 24 a , a bottom wall 24 b , side walls 24 c , 24 d and a rear end wall 24 e . Top wall 24 a includes an aperture 24 f to accommodate the trigger mechanism.
Front cap 26 is sized to be secured to the front end of housing member 24 and includes a front wall 26 a defining a piercing aperture 26 b.
Lancet 16 is of known form and includes a generally cylindrical body 16 a carrying one or more needles 16 b.
Lancet holder 18 comprises a rod suitably mounted for axial movement in the housing and having a notch 18 a.
Cocking mechanism 20 includes a button 28 mounted in housing end wall 24 e for inward and outward movement relative to the housing end wall and an actuator 30 .
Actuator 30 includes a rearward rod portion 30 a , a forward guide portion 30 b and a central resilient portion 30 c.
The rear end 30 b of rod portion 36 is fixedly secured in a socket 28 a of button 28 .
Guide portion 30 b has a generally planar configuration. Resilient portion 30 c includes an upper resilient arm 30 e interconnecting rod portion 30 a and guide portion 30 b and a lower resilient arm structure 30 f further interconnecting rod portion 30 a and guide portion 30 b . Lower resilient arm structure 30 f defines a button 30 g and is bifurcated at its forward end to form a window 30 h to accommodate axial movement of lancet holder 18 .
Trigger mechanism 22 is in the form of a trigger button sized to fit in housing aperture 24 f and defining guide structure 22 a on the underface of the button for slidable receipt of guide portion 30 b of actuator 30 .
In assembled relation of the components of the lancing device, button 28 is slidably received in end wall 24 e , lancet 16 is suitably mounted on the front end of lancet holder 18 , the rear end of actuator rod portion 30 a is coupled to button 28 , the front planar guide portion 30 b of actuator 30 is slidably received in guide structure 22 a of trigger 22 , and button 30 g is resiliently positioned proximate the underside of lancet holder 18 .
Lancet holder 18 is suitably slidably guided in housing 12 for axial movement between a retracted position seen in FIGS. 2 , 3 and 6 , a cocked position seen in FIG. 4 , and an operative puncturing position seen in FIG. 5 .
With initial reference to FIG. 2 , showing the device with the lancet holder in its retracted position, button 28 is slidably mounted in housing end wall 24 e , the upper face 22 b of trigger 22 is flush with the upper face of housing upper wall 24 a , and button 30 g of actuator 30 is resiliently pressed against the underface of lancet holder 18 rearwardly of notch 18 a.
In the transitory position seen in FIG. 3 , button 28 has been pressed inwardly or forwardly to move button 30 g into alignment with notch 18 a with this forward movement of the actuator accommodated by sliding movement of actuator guide portion 30 b in trigger guide structure 22 a.
When button 30 g moves forwardly to a position of alignment with notch 18 a the resilient nature of actuator guide portion 30 c presses the button into the notch 18 a whereupon, following release of button 28 , the actuator and lancet holder move rearwardly within the housing under the impetus of, for example, a suitable coil compression spring 30 to the cocked position seen in FIG. 4 , wherein the needle 16 b of the lancet is, for example, positioned proximate the interface of cap 26 and main body housing member 24 and the upper face 22 b of trigger 22 is positioned above the upper face of housing upper wall 24 a . This rearward movement of the lancet holder is accompanied by compression of a suitable compression spring mechanism such as shown schematically at 34 , the spring device 34 being understood to exert a lesser biasing force than the spring 32 so as not to impede the rearward movement of the actuator and the lancet holder under the bias of spring 32 .
Once the lancing device has achieved the cocked position seen in FIG. 4 , trigger 22 may be depressed as seen in FIG. 5 to resiliently displace knob 13 g from notch 13 a and allow the lancet holder and lancet to be fired forwardly under the impetus of spring device 34 to achieve the piercing or puncture position of FIG. 5 wherein a needle 16 b extends marginally forwardly of the front wall 26 a of cap 26 to achieve the patient piercing function whereafter the lancet and lancet holder retreat to the retracted position seen in FIG. 6 , corresponding to the initial position of FIG. 2 . As the lancet holder and lancet are fired forwardly, and as seen in FIG. 5 , actuator 30 and button 28 undergo a slight rebound movement but thereafter return to their initial retracted position of FIGS. 2 and 6 .
The lancing device of the FIGS. 1-7 of the embodiment will be seen to provide a simple effective and inexpensive cocking mechanism.
The lancing device 40 of the FIGS. 8-10 embodiment, broadly considered, includes a housing 42 , a lancet 16 , a lancet holder 44 , a cocking mechanism 46 , and a trigger mechanism 48 .
Housing mechanism 42 includes a main body housing member 50 and a front cap 52 defining a piercing aperture 52 a.
Main body housing member 24 includes a top wall 50 a , a bottom wall 50 b , side walls 50 c , 50 d , and an end wall 50 e . Top wall 50 a includes an aperture 50 f to accommodate trigger mechanism 48 .
Main body housing member 50 defines a lancet storage compartment 50 g defined by end wall 50 e , a longitudinal partition 50 h , a transverse partition 50 i , and overlying and underlying portions 50 a , 50 b of top wall 50 a and bottom wall 50 b , respectively. As seen, compartment 50 g is of a size to accommodate a large plurality of lancets 16 . Main body housing member 50 further defines a door 54 pivotally mounted about a vertical axis 56 proximate a rear end of the lancing device for movement between an open position, as seen in FIGS. 8 and 9 and a closed position in which access to the lancets is precluded.
Lancet holder 44 has a rod configuration and includes a detent notch 44 a and a radial arm 44 b.
Lancet holder 44 , as seen in FIG. 9 , is suitably mounted for axial movement within housing 42 between a retracted position seen in solid lines, a cocked position, and an operative or piercing position.
Cocking mechanism 46 includes an arcuate rack 60 and a pinion 62 mounted for rotation in housing member 50 by a post 50 j and having an eccentric portion 62 a for coaction with radial arm 44 b of lancet holder 44 .
Trigger mechanism 48 is schematically illustrated and may, for example, include a trigger member 66 positioned in housing aperture 50 f and a detent mechanism 68 biased downwardly against lancet holder 44 via a suitable spring mechanism 70 . With the lancet holder 18 in the solid line retracted position, and with reference to FIG. 9 , closing movement of door 54 has the effect of moving the lancet holder to its cocked position. Specifically, as the door 54 is moved from its open to its closed position, arcuate rack 60 meshingly engages pinion 62 to rotate the pinion and bring eccentric portions 62 a into engagement with lancet holder radial arm 44 b to move the lancet holder rearwardly within the housing against the resistance of a coil spring 72 . The parameters of the device are chosen such that as eccentric portion 62 a clears radial arm 44 b , detent 68 moves into detented engagement with notch 44 a so that the lancet holder is held in its cocked position whereafter, upon depression of trigger mechanism 66 to release detent 68 from engagement with notch 44 a , the lancet holder is free to move forwardly under the urging of spring 72 to achieve the piercing position. Note that in this position, since radial arm 44 b has now moved forwardly to a position in the path of radial movement of eccentric portion 62 a of pinion 62 , door 54 cannot be opened to allow access to the lancets without a specific operation on the part of the user to take the arm 44 b out of the path of movement of eccentric portion 62 a . This may be done, for example, as shown in FIG. 9 by attaching a knob 74 to the rear end of lancet holder 18 via a shaft 76 passing through housing end wall 50 e . With this arrangement, knob 74 may be turned to rotate lancet holder 44 within the housing to move radial arm 44 b out of the path of eccentric portion 62 a and allow the door 54 to be opened to allow access to the lancet storage compartment.
The lancing device of the FIGS. 8-10 embodiment will be seen to provide a convenient arrangement for storing lancets, allow access to the storage compartment to be coordinated with cocking of the lancet holder, and provide a safety feature in the sense that unauthorized or inadvertent access to the stored lancets is discouraged by requiring a specific user operation to allow unlocking of the access door to the lancet storage compartment.
The lancing device of the FIGS. 11 and 12 embodiment is generally similar to the FIG. 8-10 embodiment with the exception that the lancet storage compartment, rather than being defined within the housing by walls of the housing, is defined as an integral part of the door 54 and moves inwardly and outwardly with the door.
Specifically, the lancet storage compartment 80 of the FIGS. 11 and 12 embodiment is constituted as a drawer carried by the door 54 and is defined by the door, as the drawer face, by a floor 82 , an arcuate end wall 84 , and a partition 86 .
With this construction, as the door 54 is moved to its open position, the lancets positioned in the storage compartment 80 are moved outwardly of the housing to a position wherein they can be readily accessed from the open upper end of compartment 80 .
A method of cocking the lancing device 40 disclosed with reference to FIGS. 8-12 comprises opening a door 54 of the storage compartment 50 g to remove or deposit one or more of the plurality of lancets 16 and closing the door 54 of the storage compartment 50 g to cock the lancing device 40 , wherein closing the door 54 of the storage compartment 50 g moves the lancet holder 44 from a neutral position to a cocked position. The step of closing the door can operate a cocking mechanism 46 , for example, having a rack mounted within the housing on the door and a pinion driven by the rack engaging the lancet holder. The door 54 can be configured to pivot between the open and closed positions. The door 54 can be further configured to pivot about an axis on one edge of the door proximate a rear end wall of the housing. The lancet storage compartment 50 g can be a drawer and the door 54 can be the drawer face.
The above-mentioned embodiments have been described in order to allow easy understanding of the present invention. The invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. | A lancing device is disclosed in which cocking of the lancet holder is achieved in response to retraction of a push member. A lancing device is also disclosed in which a lancet storage compartment is provided in the housing of the lancing device and closing movement of a closure member for the storage compartment has the effect of cocking the lancet holder. Methods of cocking lancing devices are also disclosed. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for manufacturing an automotive steering rack by forming a side surface of a hollow, pile-like material with rack teeth.
2. Description of the Background Art
A usual rack used for an automotive steering mechanism or the like is manufactured from a round bar by flattening a portion of the outer periphery of the bar and then forming rack teeth on the flattened portion. As the preferred rack material, a hollow pipe is used in order to satisfy a light weight demand.
Japanese Patent Publication (JP-B 2) No. Sho 58-31257/1983 shows a method of forming rack teeth by plastically processing a rack material. In this method, a rack teeth formation portion of the material is pressed in a direction perpendicular to the axis of the material with an upper die having a tooth form which is complementary to the rack teeth.
Japanese Patent Publication (JP-B2) No. Hei 3-5892/1991 shows a method of forming a train of teeth on a flat portion of a hollow pipe-like rack material, by applying a forming die which has the same concavity and convexity as the rack teeth on the flat portion and then pressure fitting a punch into the hollow of the pipe. The flat portion of the material is forced into the concavity and convexity of the forming die.
However, both of these prior art techniques involve the preliminary step of forming a side rack teeth formation portion on a pipe which has a flat surface. This is undesired from the standpoint of productivity. In addition, the forming process requires a high pressing force (i.e., a high pressing pressure), wherein burrs are readily formed around the newly formed rack teeth.
SUMMARY OF THE INVENTION
An object of the invention is to provide an apparatus for rack manufacture, which simplifies the rack teeth forming process. It is another object of the invention to form rack teeth with comparatively low forces and with less burr generation.
According to the invention, there is provided an apparatus which is comprised of a rack material holding means for holding a hollow pipe-like rack material having a core bar inserted therein, a forming roll having an outer periphery thereof formed with a rack teeth form, a mutual moving means for causing mutual moving of the rack material holding means and the forming roll against each other in a tangential direction to the orientation of the forming roll, and a feeding means for adjusting the distance between the rack material held by the rack material holding means and the forming roll. The rack material holding means includes an angle adjusting means for varying the holding angle of the rack material against the forming roll.
The rack material holding means can also hold two rack materials in face-to-face relationship on diametrically opposed sides of the forming roll, wherein the mutual moving means causes movement of the individual rack materials in opposite directions.
Since the forming roll is pressed against each of the rack materials and the rack material is caused to move over the forming roll in a tangential direction to the orientation of the forming roll, the roll is rotated by the tangential forces caused while wedging the rack material against form of the rack teeth in the forming roll.
The present invention eliminates the need of first forming a flat surface on the material where the rack teeth will be formed, making it possible to form rack teeth directly in the round pipe. The process is thus simplified, thereby improving productivity.
Also, the inter-axis distance between the forming roll and rack material can be reduced by a feeding means for every predetermined number of cycles (for instance every cycle) of mutual rolling of the forming roll and the rack material. Thus, the forming roll incrementally wedges itself into the material every predetermined number of cycles, making it possible to form rack teeth without requiring high forces at each pass, rather, comparatively low forces can be used. Advantageously, this means the rack teeth can be formed free of burrs, and thus, it is possible to form rack teeth having excellent mechanical strength.
An angle adjusting means for varying the holding angle of the rack material to the forming roll means that the rack material can be provided with rack teeth at right angles to the axial direction of the rack material, or they may also be readily provided with rack teeth at an angle to the axial direction of the rack material.
By holding two rack materials such that they face each other on diametrically opposed sides of the forming roll while moving both of the rack materials in opposite directions, the contact forces exerted by the rack materials on the forming roll cancel each other along each point of symmetry along the roll axis. Thus, there is no need for increasing the forming roll diameter in order to ensure axial bending rigidity of the forming roll. As a result, it is possible to reduce the size of the apparatus.
Even when the forming roll diameter is reduced, the forming roll is difficult to bend, making it possible to increase the forming pressure without sacrificing the processing accuracy of the rack teeth that are formed.
Since the forming roll diameter can be reduced, the area of contact between the forming roll and workpiece can also be reduced, thereby, increasing the pressing force per unit area, thus increasing the raising of the pressed portion per rolling cycle of the forming roll, reducing the processing time.
Furthermore, since two racks can be formed at a time, the processing capacity can be doubled.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given hereinbelow and from the accompanying drawings of the preferred embodiments of the invention, which are given by way of example only, and are not intended to limit the present invention.
In the drawings:
FIG. 1 is a front view showing an embodiment of the rack forming apparatus of the invention;
FIG. 2 is a plan view of FIG. 1;
FIG. 3 is a view taken along line III--III in FIG. 2;
FIG. 4 is a schematic view showing the rack material holding means;
FIG. 5 is a detailed schematic view of an essential part shown in FIG.
FIG. 6A is a sectional view taken along line VI--VI in FIG. 4;
FIG. 6B is a detailed view showing a part shown in FIG. 6A;
FIGS. 7A and 7B are sectional views of a core bar;
FIG. 8 is a schematic view showing the processing position of the rack material relative to the forming roll; and
FIG. 9 is a schematic view showing a steering rack formed by the apparatus of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to the invention, a rack 10, as shown in FIG. 9, is obtained from a hollow round pipe which is used as rack material 11, and has a number of rack teeth 12 formed on a portion of the outer periphery of the material, traversing the axial direction of the rack material 11.
FIGS. 1 to 6 illustrate an apparatus for fabricating such rack 10. As shown, the apparatus 20 comprises a bed 21, a material clamp (i.e., material holding means) 22, a core bar setter 23, a material drive (i.e., mutual moving means) 24 and a tooth depth adjuster (i.e., feeding means) 25. With a core bar 26 inserted in the rack material 11, mutual moving of the rack material 11 and forming roll 27 is caused in the tangential direction of the forming roll 27, thus forming the rack material 11 with rack teeth. The forming roll 27 has its outer periphery provided with a rack of complementary teeth to teeth 12.
The material clamp 22 includes an angle adjuster (i.e., angle adjusting means) 28 for varying the holding angle (i.e., processing angle) of the rack material 11 to the forming roll 27.
The bed 21, material clamp 22, core bar setter 23, material drive 24, tooth depth adjuster 25 and angle adjuster 28 will now be successively described in greater detail.
(A) Bed 21 (FIGS. 1 to 3)
The bed 21 has a left and a right side plate 21A and 21B and an upper and a lower plate 21C and 21D. The bed 21 further has a pair of support posts 21E and 21F which are provided between the upper and lower plates 21C and 21D. The forming roll 27 has its opposite shaft ends rotatably supported via bearings (not shown) on the two support posts 21E and 21F.
(B) Material clamp 22 (FIGS. 1 to 6)
The material clamp 22, as shown in FIGS. 1 and 2, has a left and a right clamp housing 31 and 32, which are provided on diametrically opposite sides of the forming roll 27 such that they are in point symmetry on a point on the roll shaft axis of the forming roll 27. The left and right clamp housings 31 and 32, as shown in FIGS. 1, 2 and 4, are secured by set bolts 28B to the left and right clamp holders 33 and 34.
The left and right clamp holders 33 and 34, as shown in FIGS. 5 and 6, each has a recess 35, in which upper and lower clamp members 36A and 36B are disposed for holding a rack material 11 therebetween. The upper and lower clamp members 36A and 36B are vertically movable in the recess 35 in each of the clamp holders 33 and 34. An opening spring 37 is provided between the clamp members 36A and 36B. Pair clamp cams 38A and 38B are provided on the outer side of the clamp members 36A and 36B. The clamp holders 33 and 34 each have oil hydraulic operating chambers 41A and 4lB for plungers 39A and 39B which are screwed in the clamp cams 38A and 38B. The oil hydraulic operating chambers 41A and 41B each have a first and a second chamber 42 and 43 which are formed on the opposite sides of each of the plungers 39A and 39B. The two first chambers 42, 42 are communicated with each other by a duct line 44, and the two second chambers 43, 43 are communicated with each other by a duct line 45.
Thus, for each of the left and right clamp holders 33 and 34, a lowering of clamp cams 38A and 38B will cause oil hydraulic operating fluid to be supplied to the oil hydraulic operating chambers 41A and 41B (FIG. 6A), wherein the clamp members 36A and 36B are closed together to hold the rack material 11. Thus, a separate rack material 11 is held by a respective left and right clamp holder 33 or 34, which are in a face-to-face relationship on diametrically opposite sides of the forming roll 27, in point symmetry arrangement, ready to start the rack forming process. When the rack forming process on each of the rack materials 11 is over, operationally, each of the left and right clamp holders 33 and 34, has hydraulic operating fluid supplied to the respective second chambers 43, 43 from the oil hydraulic operating chambers 41A and 41B, causing raising of the clamp cams 38A and 38B (FIG. 6A). Thus, the clamp members 36A and 36B are opened apart by the spring force of the spring 37, thus releasing the rack material 11 from each holder 33, 34.
The clamp members 36A and 36B, as shown in FIGS. 6A and 6B, each have a respective lower surface clamp portion 46A, 46B. Each lower surface clamp portion extends over the entirety of each respective clamp 36A and 36B in the longitudinal direction thereof and has a shape substantially complementary to the pipe-like rack material 11 so that it can clamp all of the lower half and a small portion above the equator 11A of the rack material 11.
(C) Core bar setter 23 (FIGS. 2 and 4)
Each core bar setter 23A, 23B, has a respective core bar cylinder 62A, 62B provided on a rear surface of the left and right clamp holders 33 and 34. Each core bar cylinder 62A, 62B has a respective rod 26A, 26B, to which a core bar mounting bracket 63A, 63B is secured. Each core bar 26A, 26B noted above is mounted on its respective core bar mounting bracket 63A, 63B.
Thus, with advancement of each core bar mounting bracket 63A, 63B by the respective core bar cylinder 62A, 62B, each core bar 26A, 26B is set in a material insertion position between the clamp members 36A and 36B. Now, the apparatus 20 is ready to start the rack forming process on each rack material 11, 11 with the respective core bar 26A, 26B inserted therein. When the rack forming process on the respective rack material 11, 11 is over, the respective core bar cylinder 62A, 62B causes retreat of the respective core bar mounting bracket 63A, 63B. As a result, each core bar 26A, 26B is removed from the respective rack material 11, 11.
In this embodiment, the core bar is set to a predetermined position for every process. However, it is possible to have the core bar secured at a predetermined position.
(D) Material drive 24 (FIGS. 1, 2 and 4)
The material drive 24 has a base 70 secured to the upper plate 21C of the bed 21. The base 70 supports a left and a right material reciprocating cylinder 71 and 72. The left clamp housing 31 is coupled via a left coupling shaft 71A to the rod of the left material reciprocating cylinder 71, and the right clamp housing 32 is coupled via a right coupling shaft 72A to the rod of the right material reciprocating cylinder 72. The left and right coupling shafts 71A and 72A have respective racks 71B and 72B, between which a pinion 73 is provided. The left and right coupling shafts 71A and 72A are driven in synchronism to each other and in opposite directions. The pinion 73 is supported on the base 70.
Thus, by synchronizing the lowering or raising of the left coupling shaft 71A by operation of the left material reciprocating cylinder 71 with the raising or lowering of the right coupling shaft 72A by operation of the right material reciprocating cylinder 72, the material 11 held in each of the respective clamp holders 33 and 34 of the left and right clamp housings 31 and 32, is moved in opposite directions while being simultaneously forced in contact with diametrically opposite side surfaces of the forming roll 27, thus the rack material is caused to move over the forming roll in the tangential direction thereto. At this time, the forming roll 27 is rotated in the counterclockwise or clockwise direction. The left and right rack materials 11 are caused to roll in opposite directions as noted above. It should be clear that when raising the left coupling shaft 71A, the right coupling shaft 72A will be lowered to cause counterclockwise direction of the forming roll 27.
(E) Tooth depth adjuster 25 (FIGS. 1 and 2)
The tooth depth adjuster 25 has a left and a right threaded shaft 81 and 82, which are rotatably supported on the left and right side plates 21A and 21B of the bed 21. The threaded shafts 81 and 82 can be driven by motors 83 and 84. Further, the bed 21 has a left and a right slide base 85A and 86A which slidably support a left and a right transversally slidable base 85 and 86. The left and right transversally movable bases 85 and 86 have nuts 85B and 86B in which the left and right threaded shafts 81 and 82 are screwed, respectively. The left transversal slidable base 85 supports the left clamp housing 31 to be integral with respect to the leftward and rightward directions, i.e., with respect to the tooth depth direction, and be capable of relative movement in the vertical directions along the axial direction of the left coupling shaft 71A. The right transversal slidable base 86 supports the right clamp housing 32 to be integral with respect to the leftward and rightward direction, i.e., with respect to the tooth depth direction, and to be capable of relative movement in the vertical direction along the axial direction of the right coupling shaft 72A. The left transversal slidable base 85 and left clamp housing 31, and the right transversal slidable base 86 and right clamp housing 32, are coupled to each other by engagement of a groove and a protuberance for movement only in the one direction noted above.
The tooth depth adjuster 25 references off the cycle of motion of the material reciprocating cylinders 71 and 72 for the control of motors 83 and 84, which in turn cause rotation of the left and right threaded shafts 81 and 82 by a predetermined angle for every cycle of reciprocal motion of the left and right rack materials 11 caused by the material drive 24. Thus, the left and right transversal sliding bases 85 and 86 will simultaneously advance towards the forming roll 27 in units of constant extent. The advancement of the left and right transversal sliding bases 85 and 86 is caused in synchronism to the vertical movement of the left and right clamp housings 31 and 32 with respect to the forming roll 27. Thus, in every moving cycle of the left and right rack materials 11 relative to the forming roll 27, the inter-axis distance between each of the left and right rack materials 11 and the forming roll 27 is reduced, thus gradually increasing the depth of the rack teeth 12 formed in the left and right rack materials 11.
(F) Angle adjuster 28 (FIGS. 4 and 5)
The angle adjuster 28 has clamp holders 33 and 34 supported for revolution on the left and right clamp housings 31 and 32 of the material clamp 22. The clamp holders 33 and 34 are circular and fitted in revolution guide holes 31A and 32A (FIG. 2) provided in the clamp housings 31 and 32, and each clamp holder 33 and 34 has a circular arc shaped long hole 28A at both sides of the recess 35 provided the clamp members 36A and 36B and the clamp cams 38A and 38B. They are secured by set bolts 28B to the clamp housings 31 and 32 at a predetermined position of revolution in the revolution guide holes 31A and 32A. Thus, each rack material 11 will be held in the material clamp 22, and as shown in FIG. 8, each rack material will be tilted a predetermined angle with respect to the axial direction of the forming roll 27, so that the rack 10 may have rack teeth 12 at an angle to the axial direction of the rack material 11.
In the apparatus of rack manufacture 20, the sectional profile of the core bar 26, as shown in FIG. 7A, has a material support surface 90 which is spaced apart from a rack teeth forming portion of the rack material 11, the material support surface 90 being raised. Suitably, the material support surface 90 is formed by a central flat surface 91 and opposite side taper surfaces 92, 92. The resistance to deformation caused by the core bar 26 to the inner surface of the boundary portion between the flat surface, on which the rack teeth 12 of the rack material 11 are formed, and the periphery is little (since the clearance 101 is formed between the inner surface of the boundary portion of the rack material 11 and the material support surface 90 of the core bar 26). Then, the flat surface of the rack material 11 can be smoothly flatly deformed by pressing force of the forming roll 27 and no depression is formed on the rack teeth formation portion of the rack material 11 (FIG. 7B). Therefore, the depth of the rack teeth 12 becomes uniform in the tooth width direction.
The procedure of manufacture of rack 10 with the apparatus 20 of rack manufacture will now be described.
With the respective core bar setter 23A, 23B, a core bar 26A, 26B is set in the material insertion position between the clamp members 36A and 36B in each of the left and right clamp holders 33 and 34.
A left and right rack material 11 is set in the material insertion position between the clamp members 36A and 36B of each of the left and right clamp holders 33 and 34. At this time, the core bar 26 is then inserted inside the rack material 11, and each rack material 11 is then positioned in its holding position in the longitudinal direction by causing its end face to strike a respective stopper provided on each of the clamp holders 33 and 34.
With the material clamp 22, the left and right rack materials 11 are each clamped between the clamp members 36A and 36B of each of the left and right clamp holders 33 and 34. The left and right rack materials 11 are held face-to-face on diametrically opposed sides of the forming roll 27 such that they are in point symmetry with respect to a point on the roll shaft axis of the forming roll 27.
The left and right transversal sliding bases 85 and 86 of the tooth depth adjuster 25 are set in a suitable advanced position with respect to the forming roll 27. Then, with the material drive 24, the left and right clamp holders 33 and 34 are moved vertically. Thus, the materials 11 held clamped into the left and right clamp holders 33 and 34 are wedged into the outer periphery of the forming roll 27 while the inside of the pipe is supported by the material support surface 90 of the core bar 26. In this way, shallow rack teeth 12 are formed by cold processing on each of the left and right rack materials 11 as they move over the outer periphery of the forming roll 27 in opposite directions, while in point symmetry relationship with respect to a point on the roll shaft axis of the forming roll 27.
After that, in every sliding cycle of the left and right rack materials 11 relative to the forming roll 27, the left and right transversal sliding bases 85 and 86 are advanced towards the forming roll 27 in units of constant extent by the tooth depth adjuster 25. Thus, the inter-axis distance between each of the left and right rack materials 11 and the forming roll 27 is reduced, thereby gradually increasing the depth of the rack teeth 12 until the rack teeth 12 of predetermined depth can be formed.
This embodiment as described above has the following advantageous effects.
According to the invention, rack teeth 12 can be formed in a rack material 11 with the material drive 24 causing mutual moving of the rack material 11 and forming roll 27 in the tangential direction of the forming roll 27. At this time, since the forming roll 27 is pressed against the rack material 11 but the rack material 11 is caused to move over the forming roll 27 in the tangential direction thereof, the forming roll 27 is rotated by the tangential force caused while wedging the rack material 11 therein to form the rack teeth 12.
This means that there is no need for the step of first forming a flat teeth forming surface on the rack material 11, rather, it is possible to form rack teeth 12 directly into the round pipe. The process is simplified, thereby improving productivity.
The inter-axis distance between the forming roll 27 and rack material 11 can be reduced by the teeth depth adjuster 25 for every predetermined number of cycles (for instance every cycle) of mutual moving of the forming roll 27 and rack material 11. Thus, the forming roll 27 wedges incrementally into the material 11 for every predetermined number of cycles of the mutual moving, making it possible to form rack teeth 12 without requiring high forces at each pass, but rather can be done with comparatively low forces. Further, the rack teeth 12 thus formed are free from burrs which form when using high forces, and it is possible to form rack teeth 12 having excellent mechanical strength.
Since the material clamp 22 includes angle adjuster 28 for varying the holding angle of the rack material 11 against the forming roll 27, the rack material 11 may be provided with rack teeth 12 at right angles to the axial direction of the rack material 11, or it may be provided with rack teeth 12 at an angle to the axial direction of the rack material 11.
With the rack materials 11 being disposed face to face on diametrically opposite sides of the forming roll 27 since they move in opposite directions, the pressing forces exerted to the forming roll 27 by each of the rack materials 11 cancels each other due to the point symmetry with respect to a point on the roll shaft axis of the forming roll. It is thus unnecessary to increase the forming roll diameter so as to ensure the bending rigidity of the forming roll 27, thereby permitting size reduction of the apparatus 20.
Even with reduction of the forming roll diameter, it is difficult to bend the roll shaft of the forming roll 27, thus it is possible to increase the forming pressure without sacrificing the rack teeth processing accuracy.
Since the forming roll diameter can be reduced, the area of contact between the forming roll 27 and workpiece can be reduced to increase the pressing force per unit area. Consequently, the raising of the workpiece per moving cycle of the forming roll 27 can be increased to reduce the processing time. Since two racks can be formed at a time, the processing capacity can be doubled.
While the embodiment of the invention has been described in detail with reference to the drawings, the specific structure of the invention is by no means limited to the embodiment, but changes and modifications may be made without departing from the scope of the invention. For example, the tooth depth adjuster may reduce the inter-axis distance between the forming roll and rack material for every half cycle or every plurality of cycles (i.e., every predetermined rolling cycle) of reciprocal movement of the rack material.
Further, the mutual moving means does not have to be based only on the material drive 24, making it possible to move the forming roll with a forming roll drive.
While the preferred embodiments of the invention have been described in detail with reference to the drawings, they are by no means limiting, and it should be understood that various changes and modifications are possible without departing from the scope and spirit of the invention, which is set out in the following claims. | An automobile steering rack manufacturing apparatus has a material clamp for holding a hollow pipe-like rack material that has a solid core bar inserted therein. A forming roll on the apparatus has an outer periphery with rack teeth formed thereon, while a material drive causes a mutual rolling of the material clamp and the forming roll, thereby cutting rack teeth into the material. The clamp moves in the tangential direction of the forming roll orientation, and a tooth depth controller controls the distance between the rack material held in the material clamp, and the forming roll. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention is in the field of refuse collection truck equipment, especially extendable arms and grippers and the control thereof.
[0004] 2. Prior Art
[0005] Refuse trucks have long had a variety of extendable apparatuses such as arms for engaging grippers with garbage cans, dumpsters, and the like, in order that they may be lifted and their contents dumped into the hopper of a refuse truck. These apparatuses are typically fairly heavy steel devices commonly driven by hydraulics. There is a constant need in the art for smooth operation of such apparatuses in order that the trash and garbage in containers being dumped be efficiently deposited into the refuse truck without spillage, and that the apparatuses remain durable through many cycles of use. In the state of the art, devices used for control of lift arms, extensions, grippers, and other apparatuses used to reach out, grasp, lift and dump garbage cans and dumpsters have been mechanical or hydraulic in nature, such as springs, or dual-action hydraulic cylinders.
[0006] Refuse trucks also have multiple apparatuses and systems for executing multiple necessary steps in the collection of refuse. For example, after lifting and dumping trash into a hopper, the trash is packed and compressed by a separate compression mechanism. Due to the space limitations and other practical considerations, all of these multiple systems need to be assembled onto a single truck and operate together. In the prior art, where space considerations forced certain apparatuses such as packers and lifters to occupy the same space, the solution has been to simply operate them sequentially, having a consequent loss of time efficiency in many circumstances.
SUMMARY OF THE INVENTION
[0007] The present invention is a control system for a lifting and dumping apparatus for a refuse truck.
[0008] A lift arm controller for a refuse truck has a lift arm, a gripper dimensioned for gripping and holding a refuse container, a carriage disposed on the lift arm to translate along it and a gripper mounted on the carriage. A lift actuator is operationally attached to the carriage to translate the carriage, gripper and the refuse container along the lift arm. The lift actuator has a faster speed and a slower speed. At least one sensor is disposed to sense when the carriage is entering a near end portion of the lift arm and is configured to send a signal to a controller when the carriage is entering a near end portion of the lift arm. The controller is in operative communication with the sensor and the lift actuator and is configured to signal the lift actuator to operate at the slower speed when a signal is received that the carriage has reached the lift arm end portion. The sensor may be an inclinometer. The inclinometer may also be used to maintain the gripper in a substantially level orientation.
[0009] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic overview of a refuse truck.
[0011] FIG. 2 is a schematic side view of an extension arm and gripper apparatus for a refuse truck.
DETAILED DESCRIPTION
[0012] Referring now to the figures in which like reference numbers indicate like elements, FIG. 1 is a schematic top view of a refuse truck 10 . Refuse truck includes a refuse compartment 12 , receiving hopper 14 , and a cab 16 . Refuse is deposited in the hopper 14 by a lift and dump apparatus 18 . Trash is managed on board by a compressor packer apparatus 20 . An operator may control the functions of various systems on the refuse truck from the cab 16 using a central process system, adding a central processor 22 in operative electric communication with the motors, hydraulics and other equipment described below for executing necessary movements for refuse collection. The operating system may also include controls such as, for example, a joy stick 24 , a panel of switches 28 , and a display 26 .
[0013] FIG. 2 is a schematic side view of refuse collection lifting and dumping apparatus 30 . The components of the lifting and dumping apparatus 30 include an extending arm 32 configured to extend in a position to engage a garbage can, a gripper 34 typically comprised of a pair of horizontal pincers whose structure and function are well known to those skilled in the art. The extending arm 32 may be extended by any of a variety of apparatuses for that purpose, which typically include some sort of drive arm 36 engaged with a powered driver, for example, a hydraulic arm indicated schematically at 38 . In this manner, the truck may remain parked on the street, while the extension apparatus 30 extends to engage the gripper 34 with the trash can or dumpster to be dumped.
[0014] Having engaged the trash can in a known manner, the grippers must be elevated to a position where the trash can may be emptied into the hopper 14 . This is typically executed by a lift mechanism 40 which is often comprised of a lift chain 42 driven by a sprocket 44 powered by a driver such as a hydrostatic motor, which is omitted from FIG. 2 for clarity. The chain 42 extends through any of a variety of known guides and idlers down the extension arm 32 to a position where it is engaged with a carriage 50 . The gripper assembly 34 is mounted on the carriage 50 . This mounting includes a leveler for the grips 34 which may be, for example, a hydraulic arm 52 . Upon receiving a signal, the lift power supplied, for example, by a hydrostatic motor, turns the sprocket 44 , which in turn drives the chain 42 which translates the carriage 50 up and across the extension arm 32 in order to lift the grip assembly 34 and the trash can.
[0015] At the top of the extension arm 32 , the trash is dumped by tilting or inverting the trash can with the grippers 34 . This may be done actively, or, as in the depicted embodiment, by rotating the trash can in order to invert it and empty its contents. This rotation may be actuated with a curved upper portion of the extension arm 60 . By rounding the curve, the carriage 50 will tilt the grippers 34 in order to invert the trash can and empty it into the hopper 14 . Thereafter, upon receipt of a signal, the hydrostatic motor can reverse the drive of the sprocket 44 and chain 42 in order to translate the carriage 50 back down the extension arm 32 to its lower end 62 for positioning the trash can proximate to the ground once again and thereafter signaling the grippers 34 to release it.
[0016] The control system of the present invention deploys a variety of sensors throughout the lifting and dumping apparatus. These sensors include an inclination sensor 70 on the gripper assembly 34 and an inclination sensor 72 on the extension arm 32 . Sensors may also include terminal proximity sensors 74 and 76 at the upper 60 and lower 62 end portions of the extension arm 32 . Proximity sensors may further be deployed along the extension drive apparatus 36 such as depicted at 78 and 80 . Proximity sensors may be further deployed in the drive apparatus 40 such as those depicted at 82 and 84 . The sensors indicated are all in electric signal transmission communication with a central control system, and more particularly a central processor 22 . Some proximity sensors such as those at 78 and 80 may be deployed to indicate when the extension drive apparatus is fully extended and fully retracted. More particularly, these proximity sensors may be deployed near, but not at the end stop of, a fully deployed or fully retracted position. By sensing when a movement of the heavy, hydraulically driven apparatus is near its end, the receipt of the near-the-end signal from the sensor 78 or 80 may be received by the central processor 22 and may be followed by a deceleration signal from the central processor 22 to the drive means 38 for the apparatus' movement has been sensed to be nearly complete. By decelerating the movement of the heavy parts before an end stop, hard impacts that shorten the useful lifespan of the overall apparatus may be advantageously avoided.
[0017] Such damaging impacts are particularly noticeable in chain drive apparatuses. Accordingly, useful lifetime-preserving deceleration signals may be sent in response to near-the-end signals received from proximity sensors such as 74 or 76 disposed at either end of a range of travel of a chain-driven apparatus such as along the extension arm 32 . Additionally, or alternatively, the position of the carriage 50 and its load may be tracked by monitoring the chain itself 42 . Hence, a proximity sensor may be disposed at position 84 to sense the proximity of chain links or link pins in sequence and to activate a counter as they pass. The central processor 22 , having been initialized with a known number of chain links or link pins, may thereby monitor the position of the carriage 50 and load along their vertical translation up and down extension arm 32 . Alternatively, a sensor 82 may be disposed to count the passage of bolts or the components of the sprocket 44 as they pass, also thereby monitoring the position of the load. Another alternative is to engage both the chain links and the sprocket in order to have an advantageous sense of a coarse measurement and a fine measurement of the position of the carriage 50 and load.
[0018] The control system of the present invention also monitors the inclination of the grippers 34 in order to advantageously control them to maintain them and their load in a horizontal position relative to the ground as they are lifted vertically and diagonally while translating along the extension arm 32 . Hence, the inclination sensor 70 signals the central processor 22 with a signal of the inclination of the grippers 34 . Either continuously or in response to passing preconfigured thresholds, the central processor is preconfigured to output signals to the gripper leveler hydraulic cylinder 52 to execute a compensating extension or retracting of its hydraulic arm in order to tilt the grippers in a manner to maintain them in a horizontal position until they reach the top of the extension arm 60 . At the top of the extension arm 60 , the controller receives a signal indicating the arrival of the carriage 50 at the top, and thereafter outputs a signal to the gripper leveler 52 to either stop compensating, or actively retract in order to pull the grippers further over and execute the dump of the garbage can contents.
[0019] Another inclinometer or inclination sensor 72 may be placed on the extension arm itself, or, in the alternative, on the extension driver apparatus 36 . Critical inclinations may be preconfigured in the control processor to change its output signals as described below. Because of the space constraints in refuse trucks, the top portion 60 of the extension arms and some configurations, particularly those that are designed to pivot at their top, cause the top end 60 of the extension arm 32 to project into the hopper, which is disadvantageous for packing processes as the packer may impact the extension arm 32 . The present invention may advantageously output signals that alter the stop point for movement of the carriage 50 and its load upwards and towards the hopper. At higher angles of inclination, where the truck and trash can are originally closer together, the output signal would cause the carriage to travel farther around the curve at the top 60 of the extension arm 32 in order to ensure the trash can's contents are dumped. However, at greater or more horizontal extension angles, the inclination sensor 72 may indicate those angles to the central processor 22 , which may thereafter output a signal to the drive chain driver to stop at a position short of the very top end of the extension arm 32 . Because the apparatus thus extended is already inclined somewhat, only a marginally decreased amount of further inclination is needed to dump the contents. By achieving the unloading of the can without full travel of the carriage 50 , the packing apparatus may be engaged earlier, since the carriage, load and other components of the extension apparatus 30 are clear of the packer's operational travel, thus advantageously saving time.
[0020] As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. | A lift arm controller for a refuse truck has a lift arm, a gripper dimensioned for gripping and holding a refuse container, a carriage on the lift arm to translate along it and a gripper mounted on the carriage. A lift actuator is operationally attached to the carriage to translate the carriage, gripper and the refuse container along the lift arm. At least one sensor is configured to sense when the carriage is entering a near end portion of the lift arm and a signal to a controller. The controller is in operative communication with the sensor and the lift actuator and is configured to signal the lift actuator to operate at a slower speed when a signal is received from the sensor. The sensor may be an inclinometer. The inclinometer may also be used to maintain the gripper in a substantially level orientation. | 1 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to an improvement to a lubrication circuit of a vacuum pump, for the purpose of achieving numerous functions which the pump can perform by using the lubrication circuit; this is all achieved without constructional complications and with minimum additional cost.
In order to be able to reach high vacuum values, rotary pumps generally use oil as a dynamic seal for sealing coupling clearances. In order to enable the oil also to exert an indispensable lubrication action between parts moving relative to one another and to dissipate heat, it is necessary to ensure adequate circulation of the oil inside the pump.
In pumps at present on the market this circulation is achieved principally in two ways:
(a) through reduced pressure: the oil is drawn back into the vacuum pump by way of calibrated ducts through the difference in pressure between the outside and the inside;
(b) through forced circulation: the oil is driven into the interior of the vacuum pump by means of an auxiliary pump.
It is obvious that in the first solution, which is constructionally simpler (not requiring means for energizing the oil), it is not possible to take advantage in any way of the lubrication circuit to enable it to perform functions other than lubrication. Another disadvantage of this solution is that it does not permit prolonged operation of the pump at relatively high suction pressures. Under such conditions, in fact, the difference in pressure between the outside and the inside of the pump is not sufficient to enable the oil to overcome the resistance that it encounters when it attempts to enter the pump; in this situation there is consequently a risk of seizure.
The presence of an auxiliary lubrication pump not only enables the abovementioned disadvantages to be completely overcome, but also makes it possible to use the oil pressure for controlling devices whose presence is indispensable for correct and reliable installation of the pump in plant which must be exhausted. The most important of these device is the nonreturn device. In the event of the failure of the pump or of a sudden interruption of the supply, there is in fact a risk that first the oil contained in the casing and then the air will be drawn back into the pump by the reduced pressure prevailing there, and will then return into the exhausted installation by way of the suction duct, with serious consequences for the quality of the work being done and the contamination of the installation itself. It is therefore indispensable that the pump should be equipped with an appropriate nonreturn device completely isolating the suction duct from the atmosphere.
Various devices exist which enable this aim to be achieved; these may be divided into two main categories:
(a) devices maintaining the entire pump under vacuum;
(b) devices which maintain the pump at atmospheric pressure.
Those of the first category are the simplest in construction and consist of devices preventing the admission of oil or air into the pump when the latter is at a standstill. These devices can basically be constructed in two different ways, both of which are intended to close the oil admission holes of the pump when the latter stops. The first solution provides for the use of a centrifugal device and is normally adopted in pumps lubricated by suction. The second consists of a calibrated relief valve and is normally used in forced lubrication pumps; when the pump stops, the pressure drops and consequently the relief valve closes the oil supply duct of the pump.
In order to ensure the maintenance of the vacuum inside the pump, both these systems require the use of gaskets - generally of elastomer material - to form seals between the various component parts of the pump; since some of the gaskets intended to ensure dynamic leaktightness during the operation of the pump must ensure perfect static leaktightness (not normally their purpose) in order to keep the pumps under vacuum, there is actually an increased probability that leaks will occur and that tightness cannot be ensured. Finally, the centrifugal device referred to, when it is used, is normally in the form of resilient members in continuous movement and therefore subject to deterioration due to wear and/or fatigue.
It is in addition necessary to take into account two phenomena which limit the efficiency of nonreturn devices which leave the pump under vacuum:
(1) The pump under vacuum remains in communication with the suction line and, if other valves are not provided, also with the installation; since the temperature of the pump is normally higher than that of the suction line and of the installation, the oil vapors contained inside the pump tend to condense on surfaces outside the latter, and consequently also in the suction duct;
(2) When the pump is stopped with the ballast valve (for the elimination of condensable vapors) open, it is not possible to avoid the undesirable return of oil and ballast gas along the suction duct and thus to prevent the pressure in the installation from rising again.
For these reasons the nonreturn devices which leave the pump ensure greater reliability of the system. The gaskets between the various parts of the pump are in fact not required, since the same pressure exists both outside and inside the pump. Furthermore, the device is operated only on the stopping of the pump, thus drastically reducing the number of possible breakdowns due to wear or fatigue. A device of this kind is generally composed of a small piston slidable in a cylinder and received in a closure member floating on it. When the pump is stopped, a valve whose open and closed positions are brought about by the operation of the pump enables fluid at a higher pressure than that inside the pump to enter the cylinder. The piston thus slides in the cylinder and the closure member forms a seal against a seat, which is generally formed near the suction duct. In simpler cases the fluid used is atmospheric air or the air present inside the pump casing.
A centrifugal device connected to the rotor of the pump or a solenoid valve connected to the supply system of the pump, or fed by a generator fastened to the pump shaft, brings the cylinder into communication with the air when the pump is stopped. The pressure of the air then moves the piston and brings the closure member against the seal seat of the suction duct.
With a system of this kind, however, a part of the air will penetrate into the pump during the stroke of the piston, passing through the clearance between the piston and the cylinder, and will have time to pass also into the suction duct before the closure member comes to lie sealingly against its seat. This causes the pressure to rise again in the pump suction line, which is undesirable.
In order to prevent this from happening, systems have been evolved which, because of the pressure produced by an auxiliary oil pump and with the aid of an appropriate circuit, make use of the oil to operate the nonreturn device, thus preventing the air from entering the pump before the suction duct has been completely closed by the closure member.
One example of a system, of this kind makes use of the flow of pressurized oil produced by the oil pump. The oil pressure on the delivery side is kept constant by a breather valve. A second duct, branched off from the supply duct, allows a certain oil flow to pass. Because of its pressure, this oil flow pushes a piston, against the action of a spring constituting the control device, to close the aperture bringing the circuit into communication with the cylinder containing the piston of the nonreturn device. Through the action of the pressure, the oil flow passes on the sides of the piston and, after flowing above it, passes out via a hole formed in its housing and fills an uncovered chamber, from which it overflows to return to the casing. When the pump is stopped, the oil pressure falls abruptly and the spring pushes the piston and brings the cylinder of the nonreturn device into communication with the chamber previously filled with oil. The pressure prevailing in the casing causes the oil in the chamber to pass through the aperture and move the piston of the closure member. In this phase, during the stroke of the piston, it is the oil itself that operates the piston to seal the clearance between it and the cylinder and prevents air from entering. When the oil contained in the chamber has been discharged, the closure member will already have reached its sealing position against the seat of the suction duct and, since there is no longer any oil there to make a seal, the air can enter the pump by travelling along the same path as that previously travelled over by the oil.
This system successfully achieves the aim of controlling the nonreturn device in dependence on the operating conditions of the pump, of causing the control device to act only when the pump is stopped, and preventing oil and air from passing upwards again in the suction duct. However, this solution has some disadvantages:
(a) Constructional disadvantages:
it is necessary to form a suitable seat to receive the piston of the control device and it is also necessary to provide the respective ducts, with the consequent increase in size and additional work;
the auxiliary oil pump must be sufficiently large to provide a far greater flow than that required for the vacuum pump. The piston of the control device is in fact fed in parallel with the pump and is operated by the pressure drop of the oil flow through the clearance between the piston and the seat. This drop is dependent on the clearance existing, which in order not to have an excessive influence on costs must be fairly large. This entails the need for consistent flows in order to achieve the opportune drop. In view of the great variability of operating temperatures and hence of viscosity, such flows make it necessary in practice to adopt oil pumps of the positive displacement type, with their resulting cost and constructional complications;
(b) Functional disadvantages:
the flow of oil, the pressure drop of which operates the control device by collecting in a chamber, is also used as fluid for operating the piston of the nonreturn device. This oil comes from the casing and during its movement is subject to turbulence, so that to a certain extent an emulsion is formed with air. Since however there is a continuous flow, the oil collecting in the chamber does not have time to free the air mixed with it. When the pump is stopped, the oil operating the nonreturn device therefore brings into the interior of the pump a certain amount of air, which causes the pressure to rise again in the exhausted system;
the superabundant flow provided by the oil circulation pump gives rise to the undesirable generation of heat; this necessitates the use of additional heat disipation means in order to ensure the optimum operating temperature of the pump;
since the control device of the nonreturn valve is operated by an oil flow in parallel with that circulating in the vacuum pump lubrication circuit, it is only when the operating pressure has been restored in the lubrication circuit that the control device is moved from the position of rest and the nonreturn valve is opened; this means that it is necessary to wait a not inconsiderable time before the vacuum pump, when it has been put back into operation after a stop, can resume pumping from the suction line.
SUMMARY OF THE INVENTION
The system according to the invention avoids the disadvantages mentioned above.
The lubrication circuit according to the invention is connected to rotary vacuum pumps comprising a hydraulic circuit and a relative pump unit for lubrication and for auxiliary controls, including the isolation of the negative pressure space from the pump upon the stopping of the pump, with the aid of a closure member. This lubrication circuit substantially provides: for the pressure of the fluid present in the pump discharge space to be used for controlling the closure member with the aid of two ducts in series between said discharge space and an operating means for the closure member; and for a control member to be disposed between said ducts, the operation of which member is dependent on the oil pressure produced by the lubrication pump unit and propagated, with complete absence of flow, through a pressure transmission duct so as to reach the control member supervising the operation of the closure member.
More particularly, the ducts between the operating means and the discharge space of the pump have a portion directed upwards and leading into a chamber, the latter being associated with means for filling it with the oil which is to operate in said ducts.
The control member advantageously consists of a diapragm which cooperates with an aperture and which, when subjected to the pump unit pressure transmitted from the pressure transmission duct, interrupts communication between the ducts connected in series; a resilient member opposes the deformation of the diaphragm caused by the oil pressure and makes it possible to reopen communication between the serially connected ducts when the oil pressure falls; the diaphragm prevents direct communication, and therefore prevents a flow of oil between the pump unit and the duct operating the closure member.
The diaphragm is engaged on its perimeter in a cavity formed by coupling together two pump bodies, and divides said cavity into a chamber in communication with the pump unit and a chamber into which lead the two serially connected ducts of the hydraulic circuit intended for the means operating the closure member.
The means for filling the chamber with oil may consist of channels delivering the oil expelled through the discharge valves of the pump and collecting in traps, so that a few moments after starting up, the chamber is already filled with the appropriate amount of oil which had previously passed into the interior of the pump when the latter was stopped.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood upon study of the following description and the accompanying drawings, which show one practical non-limitative example of said invention and in which:
FIG. 1 shows a general longitudinal section in various planes, and
FIGS. 2, 3 and 4 show cross-sections on the lines II--II, III--III and IV--IV in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawing shows the pump unit 1 mounted on a support 2, which together with the casing 3 forms a tank for the oil 4 surrounding the pump.
On the support 2 is mounted a suction duct 5 received in a seat 6 at which the vacuum-tightness is achieved by means of a gasket 7; a piston 8 is adapted to slide inside a cylinder 9 formed in the support and operates a closure member 10 floating on the piston.
At the moment when the pump is stopped a special device, which will be described below, causes the piston 8 to slide inside the cylinder 9 until the closure member 10 comes to bear against the seal seat 11 formed at the end of the suction duct 5, thus completely isolating the latter from the pump chamber, which at this point can be filled with gas without affecting the vacuum achieved in the space which is to be exhausted.
The action of the piston 8 is achieved with the aid of a special hydraulic circuit, the operation of which is dependent on the conditions of operation and stopping of the pump. The hydraulic circuit is formed entirely inside the component parts of the pump, without it being necessary to make use of external piping and additional connections.
A cylindrical seat 15 provided in the side 12 of the pump receives a special axial pump 13 directly fastened on the rotor shaft 14. The pump 13 is situated at a level such that it is always below the surface of the oil in the tank 4 partly formed by the casing 3. On the side from which the pump 13 draws in oil the closure side face 12 of the cylindrical seat 15 carries a filter 16 preventing the admission of foreign bodies into the lubrication circuit. The oil pump 13 is of such a size as to ensure that under all possible operating conditions of the vacuum pump the flow of oil will be sufficient for correct lubrication and sealing of the clearances between moving parts. This is achieved with the aid of a lubrication duct 17 connecting the delivery chamber 15B of the pump 13 and the chambers 18 of the vacuum pump. A maximum pressure duct 17B branching off from the ducts 17 and/or 23 connects the chamber 15B to a special maximum pressure valve. The latter consists of a ball 19 forming a seal on a conical seat 20, against which it is pressed by a spring 21. The maximum pressure valve is designed to ensure that the oil will penetrate into the vacuum pump in an amount sufficient for all operating conditions of the pump.
A control duct 23 also starts from the delivery chamber 15B of the oil pump 13 and leads into a cylindrical chamber or control space 24 formed in the member coupled to the body 25 of the vacuum pump. On the face 30 of the body 25 a cavity 26 is formed, which is concentric to the chamber 24. The coupling of the two components forms a seat 29, in which the edge 28 of a resilient diaphragm 27, which hermetically separates the spaces 24 and 26, is sealingly secured. By its surface 27B the diaphragm 27 can seal in the closure duct a hole 33 leading into the cavity 26 by way of a nozzle 31 and connecting the cavity 26 to the cylinder 9 of the piston 8. A spring 32 urges the diaphragm 27 away from the nozzle 31.
A duct 34 extends from the top part of the cavity 26 and is in communication with a chamber 35 formed in the top wall of the pump body 25. By way of a channel 36 the chamber 35 is in communication with a trap 37 of the discharge valves of the vacuum pump.
During operation, the suction duct 5 of the pump is connected to the space which is to be exhausted. The pump rotor rotates the oil pump 13 fastened on it. The pump 13 draws in oil from the casing via the filter 16 and pressurizes the oil in the delivery chamber 15B. The oil pump normally used on rotary pumps is of the positive displacement type, either a vane or a gear pump. On the other hand, an important characteristic of the oil pump described here is that, since it is not of the positive displacement type, it does not isolate its suction from the delivery, and therefore, even in the event of a malfunction it still enables the oil from the casing to be returned, during the operation of the vacuum pump, through the duct 17 by the negative pressure prevailing inside the vacuum pump. The oil pump in fact is composed essentially of a helicoidal channel in the rotor 13, of appropriate pitch and section, rotating inside the cylindrical seat 15. Because of its relative velocity in relation to the screw and that of the latter in relation to the cylindrical seat receiving it, the oil contained in the channel is forced towards the chamber 15B, thus drawing an equivalent amount of oil from the casing through the filter 16.
Another important characteristic of this pump is that, since it is housed inside the pump body and is an integral part of the latter, it is beneath the surface of the oil and is therefore always primed.
The oil pressure generated by the pump is kept at a value of 120,000-150,000 pascals by means of the maximum pressure valve 21, which causes the excess oil delivery Q2 to overflow back to the casing. In this way an appropriate amount of oil Q1 can pass through the duct 17 to penetrate into the vacuum pump. At the same time the pressure is propagated, without requiring an additional flow of oil, from the delivery chamber 15B by way of the duct 23 to the chamber 24 and, overcoming the action of the spring 32, causes the diaphragm 27 to bear against the nozzle 31, thus completely isolating the closure duct 33 from the cavity 26, and therefore also completely isolating the suction duct of the vacuum pump from the vacuum pump casing. A particular feature of this arrangement is that the closing of the aperture of the closure duct 33 by means of the diaphragm 27 is achieved solely through the propagation of pressure in the duct 23, entirely without a flow, thus preventing the emulsification of the oil with the air present in the casing. Furthermore, in this way the oil pump is dimensioned for the amount of oil necessary for lubricating the vacuum pump, with advantages in respect of space occupied, a reduction of the energy absorbed by the oil pump, and a reduction of the amount of heat requiring to be dissipated; only the amount of oil strictly needed for the functional requirements of the vacuum pump is circulated at a restricted pressure.
The oil passed into the interior of the pump by way of the duct 17 is expelled together with the gas drawn in by the discharge valves, until the trap 37 is filled. The excess amount of oil then passes through the channel 36 to fill the chamber 35 and overflows from the latter to return to the casing. The oil passes from the chamber 35 by way of the aperture 34 to fill the space 26. The channel 36, the chamber 35, the aperature 34 and the space 26 cooperate to form an oil acculmulation means, whereby an amount of oil discharged from the pump may be accumulated. Any air bubbles, which are due to the fact that the duct 34 and the chamber 35 are situated at a high level in relation to the device, have time to pass readily to the outside before the device is put into action.
At the moment when the pump is stopped, the pressure generated by the oil pump 13 and also prevailing in the duct 23 and the chamber 24 rapidly decreases until it reaches the value of atmospheric pressure. The spring 22 then pushes the diaphragm 27 against the face of the chamber 24, thus bringing the duct 33 into communication with the duct 34. The difference in pressure existing between the two ducts has the effect that the oil present in the chamber 35 is returned to the space 26 and by way of the nozzle 31, which is not yet closed by the diaphragm 27, penetrates into the duct 33 and into the cylinder 9, thus pushing the piston 8 towards the suction duct 5, which is under vacuum.
When the floating closure member 10 comes into contact with the seal seat 11 of the suction duct 5, the space which is to be exhausted is completely isolated from the vacuum pump space. The oil still present in the ducts 33 and 34 is forced by the pressure existing in the casing to pass through the clearance between the piston 8 and the cylinder 9, and passes into the vacuum pump.
When the oil has passed from the chamber 35, the outside air which had forced the oil to pass through can in turn flow into the pump, thus, because of the difference in pressure between the upstream and downstream sides over the entire section of the closure member 10, contributing towards leaktightness at the seat 11. In this way, because of the sealing action of the oil in the clearance between the piston and the cylinder, there is no return of gas into the space being exhausted when the pump is stopped.
At the moment when the pump is started up again, the oil pressure is immediately restored in the ducts 17, 17B and 23, because these ducts were not drained during the stoppage of the vacuum pump. The oil pressure acting on the diaphragm 27 then recloses the duct 33 at the nozzle. The pressure inside the vacuum pump can thus be reduced, and the oil which had previously entered the pump is expelled by the valves 37 and refills the vessel 35 and the chamber 26, thus resetting the device for the next stoppage. The closure member 10, on the other hand, continues to maintain the seal against the seat 11 until the pressure inside the pump has reached a value close to that in the suction duct 5; in view of the ratio normally existing between vacuum pump chambers and the volumetric delivery of the pump, this situation is terminated very quickly; the piston 8 can thus fall again in its seating through its own weight, thus bringing the suction line and the vacuum pump into communication, without however causing any undesirable increase in pressure in the suction duct 5 of the vacuum pump.
Another important characteristic of the device is due to the fact that only slight positive pressures are required for its operation. Consequently, the oil required for lubricating the interior of the vacuum pump can be taken directly from the delivery of the oil pump, the flow being controlled by means of the calibrated aperture 17. The system is such that the oil arrives inside the vacuum pump while still under slight positive pressure and penetrates into the clearance 46 between the vanes and the hub of the rotor. The difference in pressure thus existing between the inside and the outside of the vanes pushes the latter against the surface of the stator and ensures airtightness, thus making resilient components unnecessary.
In this way, apart from the immediate saving in respect of springs and consequent machining, the rotor and the vanes are of simpler construction. Because of the absence of springs, through holes are not needed for mounting the vanes on the rotor. The rotor can thus be in one piece with the mounting for the blades and be produced by milling and grinding.
The arrangement described makes it possible to obviate the disadvantages inherent to traditional pumps having nonreturn devices, at the pressure of which the pumps are left in the atmosphere.
The control device operating the nonreturn device is in fact composed of a simple diaphragm closure member 27, 27B which is inexpensive and of small dimensions, and which can be accommodated between the component parts of the pump.
The use of the oil passing out of the discharge valves to fill the reserve chamber 35, which is necessary for operating the piston 8, permits better degasification of the oil, eliminates excessive dimensions of the auxiliary pump, which has only to ensure the delivery required for the vacuum pump, and consequently reduces the consumption of energy and the amount of heat which has to be extracted from the pump. It is thus possible to use a simple dynamic pump instead of a more expensive and complicated positive displacement pump.
It is obvious that the drawing shows only an example, which is given solely as a practical demonstration of the invention, and that the invention can be varied in respect of shapes and dimensions without thereby departing from the scope of the concept underlying the invention. The use of reference numerals in the accompanying claims is intended to facilitate the reading of the claims in conjunction with the description and the drawing, and does not limit the scope of the protection afforded by the claims. | A lubrication circuit connected to rotary vacuum pumps is composed of a hydraulic circuit and of the relative pump unit for lubrication and for auxiliary controls, including isolation of the negative pressure space from the pump on the stopping of the latter, with the aid of a closure member (10), for the operation of which use is made of the pressure of the fluid present in the pump discharge space with the aid of a duct (33, 34) between said discharge space and a means (8, 9) operating the closure member (10), which duct is subdivided into two portions between which is disposed a control member (27, 31) the operation of which is dependent on the oil pressure produced by the pump unit and propagated, with complete absence of flow, through a duct (23) so as to reach a control member (27, 31) which supervises the operation of the closure member (10). | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. application Ser. No. 10/147,226, filed May 17, 2002. This application relates to and claims priority from Japanese Patent Application No. 2001-156718, filed on May 25, 2001. The entirety of the contents and subject matter of all of the above is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a display device, and in particular, to a display device having improved its video signal drive circuit section. For example, a display device such as a liquid crystal device includes a plurality of pixels arranged in a matrix array, a circuit for selecting one from a plurality of pixel rows each comprising a plurality of pixels arranged in the x-direction, and a circuit for providing a video signal to each of the pixels in the selected pixel row in synchronism with the selection of the pixel row.
[0003] Specifically, a liquid crystal layer is sandwiched between two opposing substrates, fabricated on a liquid-crystal-layer-side surface of one of the two substrates are a plurality of gate signal lines extending in the x direction and arranged in the y direction and a plurality of drain signal lines extending in the y direction and arranged in the x direction, and each of areas surrounded by two adjacent ones of the gate signal lines and two adjacent ones of the drain signal lines serves as a pixel area.
[0004] Each of the pixel areas is provided with a thin film transistor driven by a scanning signal from one of the gate signal lines and a pixel electrode supplied with a video signal from a corresponding one of the drain signal lines via the thin film transistor. The gate signal lines are supplied with the scanning signals successively so as to select one from the plural pixel rows each comprising plural pixels arranged in the x direction, and in synchronism with this selection, each of the drain signal lines supplies a video signal voltage to a corresponding one of the pixel electrodes.
[0005] Each of the drain signal lines is connected to a video signal drive circuit. The video signal drive circuit is supplied with information formed of a certain number of bits representing a gray scale, selects gray scale voltages in accordance with the information and applies the gray scale voltages to the drain signal lines.
SUMMARY OF THE INVENTION
[0006] In such conventional display devices, for displaying the number n of gray scale levels, the number n of signal lines have been required so as to operate n switching elements each assigned to one of the n gray scale levels, respectively. Recently it has been pointed out that, in a case where the video signal drive circuit as well as the pixels is fabricated on the same substrate, it has become difficult to lay out the video signal drive circuit in a limited area on the substrate due to a recent tendency toward higher display definition.
[0007] The present invention has been made in view of the above situation, and it is an object of the present invention to provide a display device having a video signal drive circuit capable of being fabricated in a limited space and selecting from among a plurality of gray scale voltages represented by a large number of data bits.
[0008] The following explains the representative ones of the present inventions disclosed in this specification briefly.
[0009] In accordance with an embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal representing a gray-scale information to each of pixels in the selected row in synchronism with the selection of the selected row, wherein the video signal supplying circuit is provided with a transfer-data processing section for generating a data signal at a time assigned to a gray scale level, in accordance with n-bit data information representing the gray scale level, and a gray-scale voltage selector circuit section for supplying as the video signal, a piece of gray scale information selected from among plural pieces of gray-scale information, based upon the time associated with the data signal, the plural pieces of gray-scale information being successively selected.
[0010] In accordance with another embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in the selected row in synchronism with the selection of the selected row, wherein the video signal supplying circuit is provided with a transfer-data processing section for generating a data signal at a time assigned to a gray scale level, in accordance with n-bit data information representing the gray scale level, and a gray-scale voltage selector circuit section for supplying as the video signal, a voltage signal selected from among a plurality of gray-scale voltages, based upon the time associated with the data signal, the plurality of gray-scale voltages being successively selected.
[0011] In accordance with another embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in the selected row in synchronism with the selection of the selected row, wherein the video signal supplying circuit is provided with a transfer-data processing section for generating a data signal at a time assigned to a gray scale level, in accordance with n-bit data information representing the gray scale level, and a gray-scale voltage selector circuit section for supplying as the video signal, a voltage signal selected from among a plurality of gray-scale voltages, by time coincidence between the gray scale level by successive selection of a plurality of gate lines each coupled to a switching circuit associated with one of the plurality of gray-scale voltages and the data signal supplied to the switching circuit from the transfer-data processing section.
[0012] In accordance with another embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in the selected row in synchronism with the selection of the selected row, the video signal supplying circuit comprising: a digital data store section for storing n-bit data information for each of the plurality of pixels; a transfer-data processing section for generating a data signal at a time assigned to one of a plurality of gray scale levels represented by the n-bit data information, in synchronism with a clock waveform supplied to the transfer-data processing section; and a gray-scale voltage selector circuit section for successively selecting a plurality of gray-scale voltages corresponding to the plurality of gray scale levels, respectively, in synchronism with the clock waveform, wherein the gray-scale voltage selector circuit section outputs as the video signal, one of the plurality of gray-scale voltages selected from the successively selected gray-scale voltages at the time associated with the data signal.
[0013] In accordance with another embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in the selected row in synchronism with the selection of the selected row, the video signal supplying circuit comprising: a digital data store section for storing n-bit data information for each of the plurality of pixels; a transfer-data processing section for generating a data signal at a time assigned to one of a plurality of gray scale levels represented by the n-bit data information, in accordance with an output from the digital data store section, in synchronism with a clock waveform supplied to the transfer-data processing section; a gray-scale voltage generator for generating a plurality of gray-scale voltages corresponding to the plurality of gray scale levels, respectively; a selection gate circuit for successively generating a plurality of gate pulses associated with the plurality of gray-scale voltages, respectively, in synchronism with the clock waveform; and a gray-scale voltage selector circuit section for successively selecting the plurality of gray-scale voltages, in synchronism with the gate pulses, wherein the gray-scale voltage selector circuit section outputs as the video signal, one of the plurality of gray-scale voltages selected from the successively selected gray-scale voltages at the time associated with the data signal.
[0014] In accordance with another embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in the selected row in synchronism with the selection of the selected row, the video signal supplying circuit comprising: a digital data store section for storing n-bit data information for each of the plurality of pixels; a transfer-data processing section for generating a data signal at a time assigned to one of a plurality of gray scale levels represented by the n-bit data information, in accordance with an output from the digital data store section, in synchronism with a clock waveform supplied to the transfer-data processing section; a gray-scale voltage generator for generating a plurality of gray-scale voltages corresponding to the plurality of gray scale levels, respectively; a selection gate circuit for successively generating a plurality of gate pulses associated with the plurality of gray-scale voltages, respectively, in synchronism with the clock waveform; and a gray-scale voltage selector circuit section for receiving the data signal via a selection-data transfer line provided for each of a plurality of columns of pixels in the matrix array, and for successively selecting the plurality of gray-scale voltages generated by the gray-scale voltage generator, in synchronism with the gate pulses, wherein the gray-scale voltage selector circuit section outputs as the video signal, one of the plurality of gray-scale voltages selected from the successively selected gray-scale voltages in synchronism with the data signal.
[0015] In accordance with another embodiment of the present invention, there is provided a display device comprising: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in the matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in the selected row in synchronism with the selection of the selected row, the video signal supplying circuit comprising: a digital data store section for storing n-bit data information for each of the plurality of pixels; a transfer-data processing section for generating a data signal at a time assigned to one of a plurality of gray scale levels represented by the n-bit data information, in accordance with an output from the digital data store section, in synchronism with a clock waveform supplied to the transfer-data processing section; a gray-scale voltage generator for generating a plurality of gray-scale voltages corresponding to the plurality of gray scale levels, respectively; a selection gate circuit for successively generating a plurality of gate pulses associated with the plurality of gray-scale voltages, respectively, in synchronism with the clock waveform; and a gray-scale voltage selector circuit section for receiving the data signal via one of a plurality of selection-data transfer lines, the plurality of selection-data transfer lines being provided for each of a plurality of columns of pixels in the matrix array, and for successively selecting the plurality of gray-scale voltages generated by the gray-scale voltage generator, in synchronism with the gate pulses, each of the plurality of selection-data transfer lines corresponding to one of a plurality of groups formed by dividing the plurality of gray-scale voltages, wherein the gray-scale voltage selector circuit section outputs as the video signal, one of the plurality of gray-scale voltages selected from the successively selected gray-scale voltages in synchronism with the data signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the accompanying drawings, in which like reference numerals or characters designate similar components throughout the figures, and in which:
[0017] FIG. 1 is an entire equivalent circuit diagram of an embodiment of a display device in accordance with the present invention;
[0018] FIG. 2 is a detailed circuit diagram of an embodiment of a video signal drive circuit shown in FIG. 1 ;
[0019] FIG. 3 illustrates pulses supplied to a transfer-data processing section of the video signal drive circuit of FIG. 2 ;
[0020] FIG. 4A illustrates an example of a circuit functionally representing a circuit block A provided in the transfer-data processing section of FIG. 2 , FIG. 4B is a circuit diagram of an example of a concrete circuit for the circuit block A, and FIG. 4C is a timing chart for the circuit block A;
[0021] FIG. 5A displays an example of a circuit block B provided in a gray-scale voltage selector circuit section of the video signal drive circuit of FIG. 2 functionally, and FIG. 5B illustrates an example of a concrete circuit of the circuit block B, and FIG. 5C illustrates timing charts of the signals during one horizontal scanning period for the circuit block B in a case where sixty-four gray scale levels are displayed, as an example;
[0022] FIG. 6 is a timing chart illustrating operation of the video signal drive circuit;
[0023] FIG. 7 is a detailed circuit diagram of another embodiment of a video signal drive circuit in accordance with the present invention; and
[0024] FIG. 8 is a detailed circuit diagram of another embodiment of a video signal drive circuit in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Embodiments of a display device in accordance with the present invention will be explained by reference to the drawings.
Embodiment 1
[0026] FIG. 1 is a plan view illustrating a liquid crystal display device as an embodiment of a display device in accordance with the present invention, and represents an equivalent circuit of a configuration formed on a liquid-crystal-layer-side surface of one substrate SUB 1 of two opposing transparent substrates sandwiching a liquid crystal layer therebetween. Formed on the liquid-crystal-layer-side surface of the transparent substrate SUB 1 are a liquid crystal display area AR and drive circuits formed therearound. The liquid crystal display area AR and the drive circuits are formed of lamination of conductive layers, semiconductor layers, insulating layers and others which are processed into desired fine patterns, and the semiconductor layers are formed of polysilicon (p-Si) layers, for example.
[0027] As shown in FIG. 1 , fabricated in the liquid crystal display area AR are a plurality of gate signal lines GL (only one of which is shown) extending in the x direction and arranged in the y direction and a plurality of drain signal lines DL (only one of which is shown) extending in the y direction and arranged in the x direction, and each of areas surrounded by two adjacent ones of the gate signal lines GL and two adjacent ones of the drain signal lines DL serves as a pixel area.
[0028] Fabricated in each of the pixel areas are a thin film transistor TFT driven by a scanning signal from one of the gate signal lines GL and a pixel electrode PX supplied with a video signal from a corresponding one of the drain signal lines DL via the thin film transistor TFT.
[0029] The pixel electrode PX generates an electric field between the pixel electrode and a counter electrode in common for all of the pixel areas formed on a liquid-crystal-layer-side surface of the other one (not shown) of the two opposing transparent substrates, for example, and thereby controls light transmission through the liquid crystal layer. The transparent substrate SUB 1 and the other one of the two opposing transparent substrates are fixed together by a sealing member formed to surround the liquid crystal display area AR and seal up the liquid crystal layer between the two substrates.
[0030] Each of the gate signal lines GL disposed in the liquid crystal display section AR extends beyond the sealing member such that its end is connected to a vertical scanning circuit V constituting the drive circuit. The vertical scanning circuit V supplies a scanning signal to each of the gate signal lines GL, successively, and thereby turns ON all the thin film transistors TFT in the pixel areas arranged along one of the scanning signal lines GL supplied with the scanning signal. Also included in the drive circuit is a video signal drive circuit He for supplying video signals to the drain signal lines DL in synchronism with turn-ON of the thin film transistors TFT associated with the drain signal lines DL. The video signals from the video signal drive circuit He are supplied to the pixel electrodes PX via the turned-ON thin film transistors TFT.
[0031] The video signal drive circuit He is composed of a digital data store section DDS for temporarily storing digital data supplied from a circuit external to the liquid crystal display device, a transfer-data processing section TDC for transferring the digital data from the digital data store section DDS to a succeeding gray-scale voltage selector circuit section MVS, and the gray-scale voltage selector circuit section MVS for supplying video signal voltages corresponding to gray scale levels to the drain signal lines DL.
[0032] Connected to the gray-scale voltage selector circuit section MVS are a gray-scale voltage generator MVG for supplying a plurality of voltages each corresponding to one gray scale level and an address register section ARG for supplying signals such that one gray-scale voltage can be selected successively from among a plurality of gray-scale voltages from the gray-scale voltage generator MVG. Incidentally, in FIG. 1 , the gray-scale voltage generator MVG is fabricated on the transparent substrate SUB 1 , but the gray-scale voltages can be supplied from a source external to the liquid crystal display device instead of employing the gray-scale voltage generator MVG.
[0033] FIG. 2 illustrates the video signal drive circuit He in greater detail, and the same reference numerals or characters as utilized in FIG. 1 designate functionally similar portions in FIG. 2 . In FIG. 2 , for simplicity, it is assumed that three-bit information is assigned to one pixel, and thereby a voltage corresponding to one of eight (2 3 ) gray scale levels is applied to a pixel electrode PX in each of the pixel areas.
[0034] In FIG. 2 , data formed of first, second and third bits and corresponding to one pixel are stored for each of the drain signal lines DL in the digital data store section DDS. Each of the three data bits is input to one terminal of a corresponding one of three OR circuits OR 1 , OR 2 and OR 3 via a corresponding one of three inverters IN 1 , IN 2 and IN 3 , simultaneously, and the other terminals of each of the OR circuits OR 1 , OR 2 and OR 3 are supplied with pulses φ 1 , φ 2 and φ 3 in the order counted from the least significant bit, respectively.
[0035] The pulses φ 1 , φ 2 and φ 3 are alternately positive and negative (at a 50% duty cycle, for example) as shown in FIG. 3 . The frequency of the pulse φ 2 corresponding to the second significant bit is twice that of the pulse φ 3 corresponding to the most significant bit, and the frequency of the pulse φ 1 corresponding to the least significant bit is twice that of the pulse φ 2 corresponding to the second significant bit.
[0036] The pulse φ 1 (the highest-frequency pulse for time-based processing) is the same as that used for selection at a selection gate circuit SGC, and scanning signals are supplied to gate signal lines φG 0 -φG 7 successively in synchronism with the pulse φ 1 . These symbols φG 0 -φG 7 shall be used not only to designate the gate signal lines but also to specify the signals on the gate signal lines.
[0037] Outputs P 1 , P 2 and P 3 from the OR circuits OR 1 , OR 2 and OR 3 , respectively, are input to an AND circuit, to which an output P 4 from the AND circuit is supplied via a circuit block A.
[0038] FIG. 4A illustrates an example of a circuit functionally representing the circuit block A, and FIG. 4B is a circuit diagram of an example of a concrete circuit for the circuit block A. The circuit block A serves to select only the first data from among a plurality of data supplied successively from the AND circuit. As shown in FIG. 4A , the circuit block A is provided with two terminals for receiving a reset signal and the pulse φ 1 , respectively, in addition to input and output terminals. As shown in FIG. 4C , after the reset signal (High) is input, when the input IN is at a Low level, the output OUT changes to a High level, thereafter when the input IN changes to a High level, the output OUT remains at the High level during half the repetition period of the pulse φ 1 and then changes to a Low level and remains at the Low level until the reset signal changes to the High level again.
[0039] Returning to FIG. 2 , an output from the AND circuit is input to eight of the circuit blocks B via a selection-data transfer path. The reason why the eight circuit blocks B are provided for one output from the AND circuit is that each of the eight circuit blocks selects a different one from among eight gray-scale voltages. The eight circuit blocks B are supplied with pulses φG 0 , φG 1 , . . . , φ 7 , respectively and successively, from the selection gate circuit SGC of the address register section ARG, and only one of the eight circuit blocks B is selected and outputs a High level signal in accordance with a state of an output from the AND circuit. The output of each of the eight circuit blocks B controls the opening and closing of an analogue switch ASW between a corresponding one of gray-scale signal voltage lines each supplied with one of gray scale voltages V 0 , V 1 , V 2 , . . . , V 7 and a corresponding one of the drain signal lines DL.
[0040] FIG. 5A displays an example of the circuit block B functionally, and FIG. 5B illustrates an example of a concrete circuit of the circuit block B. As shown in FIG. 5A , the circuit block B is provided with a terminal for receiving the output from the AND circuit, a terminal for receiving the selection gate signal from one of the gate signal lines φG 0 -φG 7 , a terminal for receiving a start signal, and a pair of output terminals.
[0041] As shown in FIG. 5B , the circuit block B is provided with a store memory BSM for inputting and storing the output from the AND circuit based upon the input of the selection gate signal, and an active memory BAM for transferring the information stored in the store memory BSM thereinto and store it therein based upon the input of the start signal STRT.
[0042] The information stored in the active memory BAM turns ON the analog switch ASW for connecting the gray-scale signal voltage line associated with the circuit block B to the drain signal line DL. A gray-scale voltage corresponding to a video signal is applied to the drain signal line DL, and then is applied to a pixel electrode PX via a thin film transistor TFT turned ON by a scanning signal from one of the gate signal lines corresponding to the pixel electrode PX.
[0043] The feature of the liquid crystal display device having the above configuration is that only one selection-data transfer path supplies input signals to a plurality of the circuit blocks B each of which connects one of a plurality of gray-scale signal voltage lines supplying gray-scale voltages V 0 , V 1 , V 2 , . . . , V 7 , respectively, to a corresponding one of the drain signal lines DL, and consequently, this provides the advantage that the number of wiring lines in the gray-scale voltage selector circuit section MVS is greatly reduced.
[0044] FIG. 5C illustrates timing charts of the signals during one horizontal scanning period for a case where sixty-four gray scale levels are displayed, as an example.
[0045] In conventional gray-scale voltage selector circuit section, the disadvantage has been pointed out that, when three data bits are utilized for information for one pixel as in the present embodiment, eight (2 3 ) signal lines corresponding to the selection-data transfer lines are required, and therefore broken lines occurs easily, or a larger space for wiring is required.
[0046] The following explains operation of the liquid crystal display device having the above-explained configuration by reference to FIG. 6 . It is assumed that a voltage corresponding to a gray scale level 5 is applied to the pixel electrode PX of the pixel shown in FIG. 2 .
[0047] In FIG. 6 , pulses φ 1 , φ 2 and φ 3 are the same as the pulses for time-based processing shown in FIG. 3 .
[0048] The outputs from a memory for one pixel are: the first bit data=High, the second bit data=Low, and the third bit data=High, in accordance with the bit information (1, 0, 1) representing the gray scale 5 . Therefore, at time t 0 , the AND circuit is supplied with the pulse φ 1 for its input P 1 , the High level signal for its input P 2 , and the pulse φ 3 for its input P 3 , and a High level signal provided immediately after reset for its input P 4 . Since the Low level is present in at least one of the inputs at all times during time from t 0 to t 5 , the output from the AND circuit remains at a Low level during the time from t 0 to t 5 . During the time from t 0 to t 5 , the address register ARG operates in synchronism with the pulse φ 1 , and the selection gate circuit SGC supplies the pulses φG 0 , φG 1 , φG 2 , φG 3 and φG 4 to corresponding ones of the selection gates, respectively and successively. As a result, the store memories BSM 0 , BSM 1 , BSM 2 , BSM 3 and BSM 4 of the corresponding circuit blocks B change to a Low level.
[0049] During time from t 5 to t 6 , since all the inputs to the AND circuit are at the High level, the output of the AND circuit changes to the High level. Consequently, at this time, one of the circuit blocks B for controlling the signal voltage for the gray scale level 5 is coupled to the selection-data transfer line by the pulse φG 5 , and the store memory BSM 5 in this coupled circuit block B changes to the High level, and remains at the High level even after time t 6 when the pulse φG 5 has changed to the Low level.
[0050] After time t 6 , the input P 4 to the AND circuit is changed to the Low level by the function of the circuit block A, and thereafter the output of the AND circuit changes to the Low level. As a result, the store memories BSM 6 and BSM 7 in the two circuit blocks B connected to the selection-data transfer line change to the Low level.
[0051] That is to say, only the store memory BSM for controlling the signal voltage corresponding to the gray scale level 5 is at the High level, but all the remaining store memories are at the Low level. In this way the signal processing for one horizontal scanning period (the 1H period) is completed. During time from time t 9 to t 10 , when the start pulse (STRT) for the circuit block B changes to the High level, information in the store memory BSM in each of the circuit blocks B is transferred into its active memory BAM. Consequently, only in the circuit block B for controlling the signal voltage corresponding to the gray scale level 5 , its output+(positive output terminal) changes to the High level, and its output−(negative output terminal) changes to the Low level, therefore only the output of this circuit block is in the ON state, and as a result the voltage corresponding to the gray scale level 5 is applied to the drain signal line DL.
Embodiment 2
[0052] FIG. 7 illustrates a configuration of another embodiment of the liquid crystal display device in accordance with the present invention, and the configuration is similar to that in FIG. 2 . The same reference characters as utilized in FIG. 2 designate functionally similar parts in FIG. 7 .
[0053] The configuration in FIG. 7 differs from that of FIG. 2 , in that six-bit information data is utilized for one pixel, and thereby color display of sixty-four gray scale levels is realized. In this case, each of the six information bits is input to one terminal of a corresponding one of six OR circuits via a corresponding one of six inverters, and the other terminal of each of the six OR circuits is supplied with pulses φ 1 , φ 2 , φ 3 , φ 4 , φ 5 and φ 6 in the order from the most significant bit. Sixty-four circuit blocks B are provided for the output of one AND circuit, and control the opening and closing of analog switches ASW between corresponding ones of gray-scale signal voltage lines and one drain signal line DL based upon the output of the AND circuit. This means that the present invention is applicable to the display device irrespective of the number of information data bits for one pixel.
Embodiment 3
[0054] FIG. 8 illustrates a configuration of another embodiment of the liquid crystal display device in accordance with the present invention, and the configuration is similar to that in FIG. 2 . The same reference characters as utilized in FIG. 2 designate functionally similar parts in FIG. 8 .
[0055] In the Embodiment explained in connection with FIG. 2 , each of the circuit blocks B in the gray-scale voltage selector circuit section MVS is supplied with signals via only one AND circuit from the transfer-data processing section TDC. In other words, the plural circuit blocks B are connected to the AND circuit with one line (one selection-data transfer line). However, as shown in FIG. 8 , the transfer-data processing section TDC can be configured to generate two signals such that one of the two signals is supplied to odd-numbered ones of the circuit blocks B, and the other of the two signals is supplied to even-numbered ones of the circuit blocks B, for example. In this case, two pairs each composed of the AND circuit and the circuit block A connected thereto are provided in each of the time-based processing sections of the transfer-data processing section TDC, and thereby information bits from the digital data store section DDS are distributed to the circuit blocks B. In this configuration, two lines are required for each pixel for the purpose of connecting the transfer-data processing section TDS to the gray-scale voltage selector circuit section MVS, but thereby this configuration provides an advantage of slowing down the speed of the signals passing through the whole circuits.
[0056] Similarly, a plurality of circuit blocks B of the gray-scale voltage selector circuit section MVS can be divided into three or more groups, one AND circuit can be provided for each of the groups, and information bits from the digital data store section DDS can be distributed to the AND circuits in the transfer-data processing section TDC, and thereby the output of each of the AND circuits can be supplied to a corresponding one of the groups of the circuit blocks B. When information supplied to the digital data store section DDS is represented by three bits, for example, if a plurality of circuit blocks B is divided into a number of groups smaller than 2 3 , the number of wiring lines can be made smaller than in the case of conventional techniques.
[0057] While the above embodiments have been explained in connection with the drive circuits such as the video signal drive circuit fabricated on the transparent substrate SUB 1 like the thin film transistors TFT, it is needless to say that the present invention is not limited to this configuration. Even in a case where initially the above-explained video signal drive circuit He is fabricated as a separate semiconductor device and then the semiconductor device is mounted on the transparent substrate SUB 1 , the present invention is applicable to the semiconductor device.
[0058] In the above embodiments, the present invention is applied to the liquid crystal display devices, but the present invention is not to limited to the liquid crystal display device. It is needless to say that the present invention is also applicable to a display device employing light-emitting elements arranged in a matrix array, for example. In such light-emitting display devices, the basic operation of the video signal drive circuit is identical if gray-scale-generating voltages (gray-scale information) and gray-scale-generating-currents are interchanged.
[0059] As is apparent from the above explanation, the display device in accordance with the present invention makes possible selection of gray scale voltages represented by a large number of information bits by using a limited space. | A display device including: a plurality of pixels arranged in a matrix array; a selector circuit for selecting one from a plurality of rows of pixels in said matrix array; and a video signal supplying circuit for supplying a video signal to each of pixels in said selected row in synchronism with said selection of said selected row, wherein said video signal supplying circuit is provided with a transfer-data processing section for generating a data signal at a time assigned to a gray scale level, in accordance with n-bit data information representing said gray scale level, and a gray-scale voltage selector circuit section for supplying as said video signal, a voltage signal selected from among a plurality of gray-scale voltages, based upon said time associated with said data signal, said plurality of gray-scale voltages being successively selected. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to insulated pipe jacketing accessories and, more particularly, to a rain shielding accessory for preventing deterioration of jacketed pipes and/or pipe insulation as a result of water concentration and collection at the base of vertically-projecting pipe appendages such as hanger rods, valve stems, and the like.
Many industrial installations require extensive use of above-ground, outdoor pipe systems for handling a wide variety of fluids which are temperature sensitive in the sense that thermal insulation is required or desirable in the attainment of overall fluid handling efficiency. Insulation of such pipe systems, in turn, is most effectively accomplished by suspending each pipe in space from appropriate supports by depending rods connected to the pipe at spaced intervals along the length thereof, placing any of several acceptable insulating materials about the periphery of the pipe and covering the insulation with an impermeable jacketing material such as sheet plastic, stainless steel, fiber reinforced resin, or the like. The jacketing functions primarily to protect the insulation from deterioration from impregnation of dust and/or water as well as from physical damage.
Jacketing systems are available which are highly effective for encapsulation of pipe insulation and which are capable of application with relative ease to cylindrical lengths of pipe as well as to the various fittings conventionally used in pipe systems such as L's, T's, valve bodies, and the like. Various types of sheet plastic jacketing systems are particularly suited to this application because of the facility offered by such material for an hermetic seal by solvent welding and the general capability of the material to provide weather-proof encapsulation of insulated pipes and fittings.
With all such available insulation jacketing, particularly in outdoor pipe installations, a serious problem is presented by the presence of vertically-projecting pipe appendages such as hanger rods, valve stems, and the like. Such pipe appendages must project through the insulation and jacketing in a way so as to require a caulking-like sealant between the stem or rod and the pipe jacketing in order to effect a complete hermetic seal. Such sealants, however, even with regular maintenance, deteriorate with age and exposure to result in a leakage point in the context of the overall hermetic seal provided by the jacketing. Moreover, because of the location of the caulking-type seal at the base of the vertically-extending rod or valve stem, the point of leakage is most vulnerable to water running down the surface of the rod or valve stem. As a result of this problem, serious damage is caused both to the insulation underlying the jacketing, components entrained in the insulation, and often to the pipe itself. The wetting of insulation in the base of hanger rods, valve stems, and the like, can require replacement of insulation as often as once a year in many industrial installations. Also, because of the toxic nature of the atmosphere in which industrial pipe systems are used, rain water can become sufficiently corrosive to damage the pipe itself, particularly in the concentrated area underlying a suspension rod, for example. In other types of installations where electrical tracers are embedded in the insulation, the tracers are severely damaged so as to require replacement on a regular basis.
In light of the foregoing, it will be appreciated that there is need for an acceptable solution to the problems associated with leakage of pipe insulation jacketing in the region of hanger rods, valve stems, and the like.
SUMMARY OF THE INVENTION
In accordance with the present invention, the problems associated with seal deterioration in pipe insulation jacketing at the base of such vertical appendages as hanger rods, valve stems, and the like, are substantially alleviated by the provision of a rain shield which is inexpensive, which is easily applied to existing pipe systems and which is highly effective to prevent water from penetrating insulation jacketing at the base of such vertical appendages. Structurally, the rain shield of the present invention is in the nature of an inverted funnel-shaped member formed of resilient sheet material such as plastic which is precurled to provide a substantial volute overlap extending throughout the length of the member with the sheet material in a relaxed condition. The cylindrical upper portion of the inverted funnel-shaped member as well as the remainder of the member is opened and placed transversely about a rod or stem and then allowed to spring back to its original or normal condition. An effective seal of the upper neck portion of the member is achieved by an appropriate mastic and a conventional stainless steel pipe clamp, for example. The lower, downwardly diverging portion of the member may be shaped to conform with the pipe insulation jacketing or merely spaced therefrom in the nature of a protective roof preventing water from access to the juncture of the appendage with the major portion of the pipe insulation jacketing.
A principal object of the present invention is, therefore, to provide a rain shield for insulated and jacketed outdoor pipe installations which is particularly effective in avoiding the problems associated with water leakage at the base of hanger rods and valve stems. Other objects and further scope of applicability of the present invention will become apparent from the detailed description to follow taken on conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a conventional outdoor pipe installation incorporating an exemplary embodiment of the present invention;
FIG. 2 is an enlarged fragmentary perspective view in partial cross section illustrating the organization of a conventional,outdoor pipe hanger;
FIG. 3 is an enlarged side elevation illustrating the rain shield of the present invention after installation;
FIG. 4 is a fragmentary perspective view illustrating the upper portion of the rain shield of the present invention in a normal unstressed condition; and
FIG. 5 is a fragmentary perspective view showing the portion illustrated in FIG. 5 in an open condition for application to a pipe hanger rod or valve stem.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1 and 2 of the drawings, the rain shield of the present invention is designated by the reference numeral 10 and shown with a section of pipe representing a typical insulated outdoor pipe installation. Thus, a cylindrical pipe 12, circumscribed by a layer of insulation 13 and an exterior jacket 14, is suspended above the ground from a plurality of inverted U-shaped standards 15 by hanger rods 16 depending from the standards to a pipe carrier affixed to the pipe 12. In the drawings, the pipe carrier is represented by a band 18 having upturned end flanges 20 bolted or otherwise secured to an eye 22 at the base of each of the hanger rods 16. While the illustrated connection of the rod 16 to the pipe 12 is typical, it is merely representative of a wide variety of such connections and may range from a simple direct welded connection of the rod 16 to the pipe 12 to an assortment of pipe saddles differing substantially from the organization of the band 18. It is to be noted, however, that the physical connection of the rod 16 is internal or directly to the pipe 12 as distinguished from exterior to or about the jacketing 14 in order to facilitate placement and maintenance of the insulation and jacketing as well as to avoid the deleterious effects of compacting the insulation 13 under the weight of the pipe 12 and its contents.
The result of the internal connection of the hanger rod 16 to the pipe 12 is, as depicted in FIG. 2 of the drawings, a break in the continuity of the external jacketing 14 due to the need for the pipe supporting structure to extend through the jacketing 14 and the insulation 13. In the illustrated example, the flanges 20 of the band 18 project through the insulation 13 and jacketing 14. Heretofore, continuity of the jacketing seal at the base of the rod 16 has been effected by caulking or placement of a mastic-type sealing compound throughout the region at the juncture of the jacketing 14 and the flanges 20 (in the illustrated arrangement) in order to prevent water from passing through the jacketing to the insulation 13 and pipe 12. Although available caulking materials are admirably suited to effect such a seal, they are vulnerable to deterioration in time by exposure to elements and constitute a weakness in the jacketing seal at a most vulnerable point due to the potential for rain water and the like to collect on and run down the length of any one of the rods 16. A similar condition is presented by other vertical pipe appendages such as the stem of a valve actuator 24 (FIG. 1). Effective sealing at the stem of a valve is even more aggravated as a result of the need for the valve stem to rotate relative to the jacketing 14 and the pipe 12.
A more complete understanding of the rain shield 10 may be had by reference to FIGS. 3-5 of the drawings. In particular, the rain shield is constituted by an inverted funnel-shaped member 26 formed of resilient sheet plastic material such as polyvinyl chloride, polystyrene, ABS, and the like. The configuration of the member 26 thus defines an upwardly converging frustoconical body portion 28 joined at its upper or small end with a coaxial cylindrical neck portion 30. The member 26 preferably includes two longitudinal half sections 26a and 26b secured along the complete length of the member throughout the frustoconical body 28 and the neck portion 30 by solvent welding along a seam 32. As a result of this construction, the two longitudinal half sections of the member 26 may be preformed by vacuum-forming techniques so that in a relaxed state of the sheet material from which the member is formed, the sheet material will overlap on the side opposite from the seam 32 to provide a substantial voluted overlap particularly in the region of the neck portion 30. As may be observed in FIG. 4, for example, the voluted overlap in the cylindrical neck portion 30 extends through approximately 180 degrees principally to accommodate a wide range of rod diameters about which the neck portion will be fixed in the manner to be described in more detail below. The overlap along the body 28 of the member 26 may be diminished in the interest primarily of conserving material.
The thickness of the plastic material from which the member 26 is formed may vary depending on the size of the member 26 principally to insure adequate strength so that it will retain its normal configuration under an essentially relaxed state of the sheet material from which it is formed. It is important, however, that the sheet material be sufficiently resilient so that it may be spread to an open condition as represented in FIG. 5 of the drawings to be laterally placed about a rod or valve stem and returned to its original or normal closed configuration under the elasticity of the sheet material. Using any of the plastic materials indicated above, it is contemplated that the sheet material from which the member 26 is formed may vary in thickness from 0.010 to 0.060 inches.
Placement of the rain shield 10 on either the stem of the valve actuator 20 or the rod 16 to the position illustrated in FIGS. 1 and 3 is achieved very simply by first placing a mastic-like flashing compound either on the interior of the neck portion 30 of the member 26 or about the exterior of the rod or valve stem, opening the member 26 to the approximate configuration illustrated in FIG. 5 and applying the same laterally against and about the hanger rod 16 or valve stem. By relieving the stress holding the member 26 in such an open condition, the inherent resiliency of the sheet material will cause it to resume its normal closed condition about the rod or valve stem. Thereafter, it is secured in place by application of a stainless steel hose clamp 34 (FIG. 3) applied about the cylindrical neck portion 30. The frustoconical body portion 28 is secured in the closed condition by inserting one or more self-tapping screws 36 in the region of the body overlap. The screws 36 are preferably nylon screws which are adequate for the needed retention of the overlapped portions of sheet material and which are highly resistant to corrosion.
The bottom of the frustoconical portion may be first cut to shape in the field to conform with the configuration of the jacketing 14 and either solvent welded or otherwise secured in place using an appropriate adhesive. Such securement, however, is not needed for effective functioning of the rain shield. In its application to the stem of the valve actuator 24, for example, the bottom lip or edge of the member 26 might be spaced slightly from the jacketing 14 to allow rotation of the valve actuator and the rain shield as a unit relative to the outer jacketing.
Thus, it will be appreciated that as a result of the present invention a highly effective rain shielding accessory for jacketing pipe installations is provided by which the stated objective among others are completely fulfilled. Also, it will be apparent to those skilled in the art and it is in fact contemplated that modifications of the embodiment illustrated and described herein may be made without departure from the present invention. Accordingly, it is expressly intended that the foregoing description and accompanying drawings are illustrative only, not limiting, and that the true spirit and scope of the present invention will be determined by reference to the appended claims. | A rain shield accessory for jacketed insulated pipe installations having vertically projecting rod-like appendages such as hanger rods, valve stems, and the like. The rain shield is an inverted funnel-shaped member of resilient sheet material so as to define a frustoconical body portion joined at its upper or small diameter end with a coaxial cylindrical neck portion. The sheet material from which the member is formed is precurled about the axis of the body to provide a voluted overlap particularly in the region of the cylindrical neck portion so that the member can be opened and placed about rod-like appendages of widely varying diameters. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 09/116,187 filed Jul. 15, 1998 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to gripping apparatus for power tongs and backup tools used in the oil and gas industry.
2. Description of the Prior Art
Power tongs and backup tools are devices used to secure together (make up) and detach (break out) threaded ends of adjacent sections of tubular products such as production tubing, casing or drill pipe by gripping, applying torque to, and rotating one of the sections. A power tong applies torque to one tubular member section to cause it to rotate. A backup tool holds the adjacent tubular member section much as pipe wrenches are used often in conjunction with a power tong to grip and prevent rotation of the adjacent sections of tubular product. A backup tool is also capable of applying torque to the tubular product section.
Conventional power tongs and backup tools used in the oil industry often damage the tubular sections. In recent years, major oil companies have required that strings of tubular products must be coupled ("made up") and decoupled ("broken out") with a minimum of (i) damage to the tubular products from teeth marks; (ii) deformation of the tubular products; and (iii) cracking of cement or plastic coating on the inside of the tubular products. The goal of these requirements is to minimize concentrations of corrosion and stress on the tubular products resulting from the tears and gouges caused by the gripping teeth of power tongs and backup tools. Also, to maintain integrity of the threaded connection it is desirable to reduce deformation of the pipe by the power tong and backup tool near the location of threads during makeup to assume more compatible meshing of the threads of adjacent products and reduce frictional wear.
U.S. Pat. No. 5,172,613 issued Dec. 22, 1992, entitled "Power Tongs with Improved Gripping Means" ("Wesch I") and U.S. Pat. No. 5,542,318 issued Aug. 6, 1996, entitled "Bidirectional Gripping Apparatus" ("Wesch II") are incorporated herein for all purposes. The Wesch I patent discloses a cam ring turned against a concentric drag ring which moves the gripping assemblies into and out of contact with the tubular surface of the pipe. The Wesch II patent discloses bidirectional gripping assemblies having a double-seated linkage which supports a pivoted jaw within a housing so that the jaw may be used to grip a pipe and exert radial force thereon to hold the pipe against the torque applied in opposite directions. U.S. Pat. No. Re. 31,993 (also incorporated herein by reference for all purposes) issued Oct. 1, 1985, as a reissue of U.S. Pat. No. 4,281,535 describes apparatus to accomplish the task of making and breaking of threaded joints tubular products using wrap-around pivoted jaw assemblies.
Generally, gouging and tearing of pipe is caused by (i) ineffective gripping assemblies; (ii) gripping jaws having insufficient gripping force; of (iii) the gripping surface or the teeth. These conditions can over-stress the pipe when radial force is applied in addition to the torsion force required to either hold or apply torque to the tubular member. The gripping surface (wheather teeth or any other friction surface which increases the coefficient friction between the gripping assembly and the pipe) must be designed to substantially conform to the outer surface of the pipe even though the pipe may not be round or the tong may not be located transversely to the pipe at the time of gripping. Any improper alignment causes reduced contact areas between the pipe and gripping system. Thus it is important that proper alignment be maintained.
Conventional clamp backup tools apply gripping force to jaws by with hydraulic rams or arms actuated directly by hydraulic rams. It has been demonstrated that counterforces on the jaws caused by applied torque may compress such oil in the hydraulic rams sufficiently to cause skidding of the pipe on the gripping surfaces. Even at 3,000 P.S.I., oil is soft compared to the mechanically applied gripping force discussed herein.
Normally, conventional tongs and backup tools do not apply the gripping force evenly around the pipe. Instead, it is applied to areas around the pipe which are insufficient to minimize the causes of deformation and teeth marks on the surface of the pipe. The balanced pivoted jaws of U.S. Pat. No. Re. 31,993; U.S. Pat. No. 5,172,613 and U.S. Pat. No. 542,318 solve these problems.
U.S. Pat. No. 5,669,653 discloses a backup tool in which a cam wedge is pushed by a fluid cylinder using pivoted jaws. FIG. 3 of U.S. Pat. No. 4,463,635 also discloses a tool having a wedge block which uses a roller to operate two arms to grip a cylinder. Since the wedge is pushed in the tool disclosed in U.S. Pat. No. 5,669,653 in order to cause gripping of a tubular member, the backup tool is unusually long and cumbersome to mount on the power tong. U.S. Pat. No. 5,669,653 also shows the actuating fluid cylinder with two bolts or pins at its base. Seldom is oil field pipe truly round. Accordingly, if an egg-shaped pipe cross section is gripped, side load is transferred to the wedge and therefore to the fluid cylinder.
SUMMARY OF THE INVENTION
In accordance with the present invention, apparatus is provided for gripping the exterior of a tubular member to resist bidirectional rotation of the member from applied torque about the longitudinal axis of the tubular member. The apparatus comprises a body to receive the tubular member and a reactive gripping jaw attached to the body. A pair of arms having first and second ends is provided. Each of the arms is pivotally mounted on the body about an axis parallel with the longitudinal axis of the tubular member. The first end of each arm supports an active gripping jaw and the active gripping jaws, in conjunction with the reactive gripping jaw, receive and secure the tubular member.
A force multiplying device is interposed between the second ends of the arms for engagement with the second ends of the arms. An actuator is coupled to the force multiplying device for moving it in a first direction to engage the second ends of the arms and pivot the arms to move the active gripping jaws so that the tubular member is secured between the reactive gripping jaw and the active gripping jaws with force sufficient to prevent rotation of the tubular member at a predetermined applied torque. The active gripping jaws are disengaged from the tubular member by returning the force multiplying device to its initial position.
In one embodiment the force multiplying device comprises a roller attached to the second end of each arm and a wedge member with two inclined surfaces intermediate the pair of arms for engaging the roller of each arm. Biasing apparatus is provided for maintaining engagement of the rollers against the inclined surfaces. In another embodiment the force multiplying device comprises an arcuate cam surface on the second end of each arm and rollers operatively coupled to the actuator for engagement with the arcuate cam surfaces of the arms. Biasing apparatus is also provided for mounting engagement of the rollers with the arcuate cam surfaces. In yet a third embodiment the force multiplying device comprises a toggle block pivotally coupled to the arms with toggles.
In accordance with the present invention the force applied to the pipe outer surface is predetermined and mechanical instead of being applied by a hydraulic ram directly to the jaw. The consequential radial loading to the three jaws on the pipe outer surface is sufficient to keep the pipe from rotary skidding at gripping surfaces when predetermined torque is applied to the pipe.
In the present invention surfaces on jaws having a high coefficient of friction are urged into frictional engagement with the surface of an elongated member having an outer surface and a longitudinal axis. When force is applied to the elongated member which tends to rotate the elongated member either clockwise or counterclockwise, the surfaces of the jaws are clamped to the elongated member to increase pressure between the gripping surfaces on the jaws and the surface on the elongated member.
For any given torque, the radial force is predetermined and uniformly applied on the pipe. The gripping jaw area as well as, number and size of hardened teeth are predetermined to reduce the forces which tend to cause teeth marks or crush the tubular body to a magnitude less than the yield strength of the tubular body. In other words, the number and shape of the hardened teeth in the gripping surface is predetermined so that the force of the teeth on the pipe does not exceed the elastic limit or the ultimate strength of the pipe material at maximum torque. Apparatus employing the invention will hold pipe against either clockwise or counterclockwise rotation, thus obviating the need for changing the structure or the magnitude of force required to hold the pipe against torque applied in either direction.
Where marks are absolutely forbidden, the gripping jaw surfaces may be smooth or sandpaper-like and the gripping force increased sufficiently over standard gripping jaw surfaces to keep the gripping jaw surfaces from skidding on the elongated member.
In another embodiment a backup tool is provided with a jaw assembly including replaceable gripping inserts with hardened teeth. This embodiment is designed to engage varying diameter tubular members with a gripping force proportional to the applied torque and acts as a unidirectional backup tool with a support system to accommodate reversal of the backup tool for applying gripping force to make or break threads in either direction of the power tongs.
BRIEF DESCRIPTION OF THE DRAWING
For a more complete understanding of the present invention and advantages thereof, reference is made to the following description taken in conjunction with the accompanying drawing in which:
FIG. 1 is a plan view of a bidirectional backup tool in accordance with the present invention which has a pipe clamped in the jaws of the tool.
FIG. 1A is a side elevation view of the bidirectional backup tool of FIG. 1.
FIG. 1B is a plan view of the bidirectional backup tool with jaws open.
FIG. 1C is a partial break-out of the jaw in FIG. 1 to illustrate various force vectors.
FIG. 1D is an enlarged break-out of the circled area in FIG. 1.
FIG. 2 is a plan view of bidirectional backup tool with jaws open.
FIG. 3 is a partial sectional view taken along section 3--3 of FIG. 1B with a spring supporting mechanism.
FIG. 4 is a partial sectional view taken along lines 4--4 in FIG. 2.
FIG. 5 is a partial sectional view taken along lines 5--5 in FIG. 2.
FIG. 6 is a sectional view taken along line 6--6 in FIG. 2.
FIG. 7 is a plan view of an alternate embodiment of the bidirectional backup tool with jaws closed.
FIG. 8 is a plan view of a toggle arrangement for moving the jaws into engagement with the pipe.
FIG. 9 is a plan view of an alternate embodiment of the bidirectional backup tool with jaws open.
FIG. 10 is a partial sectional view taken along the lines 10--10 of FIG. 9.
FIG. 11 is an alternate embodiment of the jaw assembly of FIG. 10.
FIG. 12 is a partial sectional view taken along the lines 12--12 of FIG. 13.
FIG. 13 is a partial top view of FIG. 12.
FIG. 14 is a partial sectional view taken along line 14--14 of FIG. 15.
FIG. 15 is a partial top view of FIG. 14.
FIG. 16 is a plan view of a power tong gripping jaw.
FIG. 16A is a plan view of a cam ring in a power tong.
FIG. 16B shows power tong force vectors.
FIG. 17 is a plan view of alternate embodiment of unidirectional backup tool gripping a large diameter pipe.
FIG. 17A is a broken-out view of FIG. 17 clamping a small diameter pipe.
FIG. 17B is a broken-out view of the jaw assemblies if FIG. 17 in the open position.
FIG. 18 is a front view of the gripping assembly of FIG. 17 for handling different pipe sizes with the same rotary gripping means.
FIG. 19 is a partial cross sectional view of the cylindrical dies in FIG. 17.
FIG. 20 is an alternate arrangement for rotary gripping dies.
FIG. 21 is a plan view of a bidirectional backup tool in accordance with the present invention which has a pipe clamped in the jaws of the tool.
FIG. 22 is plan view of the tool of FIG. 21 with the jaws open.
FIG. 23 is a schematic drawing illustrating various force vectors in the tool of FIG. 21.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1, 1a, 1b, 1c, 1d and 2 illustrate a bidirectional backup tool 10 which has a frame or body 9 formed by spaced top and bottom plates 20 and 21, respectively, with a pair of pivot arms 22 and 23 pivotally secured to the body 9 by pivot pins 24 and 25, respectively. Active jaws 26 and 27 and reactive jaw 28 are positioned within the bidirectional backup tool 10. Active jaw 26 is attached to pivot arm 22 by jaw pin 29 and active jaw 27 is attached to pivot arm 23 by jaw pin 30. Reactive jaw 28 is attached between top and bottom plates 20 and 21, respectively, by bolts 31 which also space top and bottom plates 20 and 21 apart by the width of flange 32 on reactive jaw 28. While FIG. 1 depicts the components of backup tool 10 as symmetrical about a center line from left to right, those skilled in the art will appreciate that the components of such a tool may not always be absolutely symmetrical.
Pipe 33 is held within active jaws 26 and 27 and reactive jaw 28 by hardened replaceable inserts 34, 35 and 36, respectively, which substantially conform to the outside diameter of the pipe. Inserts 34, 35 and 36 have friction surfaces adjacent the pipe to increase the coefficient of friction. These may be teeth, a sandpaper-like finish or other finish for the inserts 34, 35 and 36 or a brake-band type material or non-ferrous alloy design to minimize damage to the pipe under full compressive load. Replaceable inserts 34, 35 and 36 may, for example, be secured to backup tool 10 in dovetail grooves 26a (FIG. 4) or by screws.
Conventional backup tools apply gripping force to the pipe through hydraulic rams. However, the counterforce (which is generated by the pipe as torque), tends to open the jaws by compressing the oil in the hydraulic cylinders. The embodiment shown as backup tool 10 eliminates that problem by using a force loading block or wedge block 37 (FIG. 2) with inclined surfaces which provide cam-like or ramp faces. The inclined surfaces preferably have inserts 38 and 39. Inserts 38 and 39 are preferably replaceable and are secured to force loading block 37 by 72 and 73 and 72a and 73a, respectively. The piston of fluid cylinder 40 is in threaded engagement with force loading block 37.
By actuating fluid cylinder 40 (which may be a hydraulic or air cylinder), force loading block 37 is pulled to the right in FIG. 2, causing the pivot arms 22 and 23 to pivot around the pivot pins 24 and 25. Active jaws 26 and 27 of pivot arms 22 and 23 are then moved into engagement with the pipe 33. Initially, edges 45 and 46 of force block 37 engage rollers 43 and 44 of pivot arms 22 and 23 which moves active jaws 26 and 27, respectively, snugly against pipe 33. Thereafter, cam surfaces on inserts 38 and 39 engage rollers 43 and 44 and pivot arms 22 and 23 rotate about pivot pins 24 and 25, respectively, applying force through active jaws 26 and 27 against the pipe 33. The pipe 33 thus abutts reactive jaw 28 in proportion to the pulling force of fluid cylinder 40. To release the pipe 33, force block 37 is pushed by fluid cylinder 40 to the left in FIGS. 1 and 2 into the retracted position shown in FIG. 2.
The combination of force loading block 37 and the rollers on pivot arms 22 and 23 comprise a force multiplying device because the force exerted on rollers 43 and 44 by the actuator 40 to move the arms so that the active jaws are brought into gripping engagement with the pipe is substantially less than the force applied to the pipe.
An extension spring 48 is attached to each pivot arm 22 and 23. Extension spring 48 functions to bias rollers 43 and 44 toward surfaces 45 and so that the pivot arms 22 and 23 to move active jaws 26 and 27 in and out of engagement with pipe 33.
Since the radial force FRT on pipe 33 is very large, all rollers and cam surfaces must withstand the large compressive stresses generated during operation. Hardness of Rockwell C-29 to C70 is required. Rockwell C-37 to C62 is preferred.
As shown in FIG. 1 the top and bottom plates 20 and 21 are tied together by plates 100 and 101 which may be welded to both. These bear against legs 102 and 103 rigidly attached to a power tong. Torque may be measured with a pancake fluid cylinder 104 placed between plate 100 and leg 102 and connected to pressure gauge 105.
In operation, load block 37 is pulled by fluid cylinder 40 from position 47 to the position shown in FIG. 1. This brings the insert 34 and insert 35 of active jaws 26 and 27, respectively, snug against the outer surface of pipe 33 abutting reactive jaw 28. Further pull by fluid cylinder 40 increases the forces applied (denoted as force F1 on insert 34, force F4 on insert 35 and F5 on insert 36) to the surface of pipe 33 to a force predetermined to be sufficient to hold the pipe from rotating.
If force F1 (FIG. 1C) is known, then the force F3 (FIG. 1D) on roller 43 where it contacts the angular cam section at point 49 can be determined. Force F2 is determined by multiplying the tangent of the cam angle A times the force F3. Two times the force F2 is used to determine the sizing of fluid cylinder 40.
When resisting rotation of pipe 33, any counterforce generated by the gripping force FT of inserts 34, 35 and 36 (FIG. 1C) against the pipe 33 is applied directly to rollers 43 and 44 and thus against the hard surfaces of force block 37 or inserts 38 and 39. Compression of the fluid in cylinder 40 is thus minimized and a very rigid clamping arrangement is obtained. The length of insert 38 is sufficient to allow fluid cylinder 40 to force roller 43 in a clockwise direction around pivot pin 24 and roller 44 in a counterclockwise direction around pivot pin 25 with sufficient movement to allow for tolerances in pivot pins 24 and 25, jaw pins 29 and 30, and roller pins 50 and 51 and variations in the pipe 33 outside diameter and still maintain in constant force on roller 43 and 44. The total gripping force applied when rollers 43, 44 are in contact with inserts 38, 39 is the sum of force F1, F4 and F5 (designated as force FRT in FIG. 1C). Force FRT is the force required to overcome the tangential force (FT in FIG. 1C) by a group factor (FRT÷FT) of about 1.2 to as much as 15 or more. The grip factor varies, of course, depending on insert gripping surface configuration and contact area of the active jaws 26, 27 and reactive jaw 28. This configuration is predetermined to minimize damage to the pipe 33. The tangential force FT in inch-pounds is determined by multiplying the applied torque from the power tong by twelve (12) and dividing that value by R, the outside radius of pipe 33. This value is the force which must be overcome by the grip factor applied to radial force FRT. It will appreciated that inserts 34, 35 and 36 may be of different thickness to accommodate the outside diameter of various pipe sizes. Thus several pipe sizes may be handled by the backup tool by changing only the inserts without changing the jaws. The total radial force designated (FRT) is determined by calculation and is normally three to four times the tangential force (FT) but may be adjusted by trial and error. Rollers 43 and 44 are centered in pivot arms 22 and 23 by roller pins 50 and 51. All pins and pivots are heat treated and provided with zerk grease fittings.
Pipe 33 is an elongated cylindrical product such as a hollow joint, tubing, casing, solid bar, drill pipe or other tool used in well drilling, completion and servicing operations. While the tubular product illustrated in FIG. 1 is circular, it should be appreciated that the cross-section of the tubular product may be other than circular. If desired, a mechanical advantage can be realized to reduce the forces of the rollers 43 and 44 on the inserts 38 and 39, respectively, by reducing the distance between jaw pins 29 and 30 and pivot pins 24 and 25, respectively, or by increasing the distance between pivot pins 24 and 25 and roller pins 50 and 51, respectively.
The space 52 (FIG. 1) between pivot arm 22 and active jaw 26 may be confined by surfaces 53 and 54. This space is predetermined to limit the rotation of active jaw 26 with respect to pivot arm 22.
This applies as well to active jaw 27 and any other pivoted jaw arrangements e.g., the embodiment of FIG. 7.
The entire gripping system indexes on the outer surface of pipe 33. The active jaws 26 and 27 are pushed against the pipe 33 by pivot arms 22 and 23 when actuated by rollers 43 and 44 moving on surfaces 45 and 46 and inserts 38 and 39 on force loading block 37. In turn, pipe 33 is forced into reactive jaw 28. Should the pipe 33 be out of round or otherwise not aligned with the inserts 34, 35 and 36, the force loading block 37 can move angularly compensate and assure an even gripping. Angular compensation is possible because the fluid cylinder 40 may pivot on pin 55 so that the force loading block 37 can move as required to assure alignment with pipe 33. Active jaw 27, reactive jaw 28 and inserts 35, 36 have keyways 56a and keys 56 similar to those in active jaw 26 and insert 34.
In FIG. 2, the backup tool 10 is illustrated with the jaws open. Insert 34 is secured to active jaw 26 by a key 56 in a keyway 56a. With insert 34 installed, the torque forces are absorbed by the key 56. Key 56 extends substantially through the length of insert 34 and is retained by bolt 56A and washer 56B as shown in FIG. 1C.
FIG. 3 is a section view taken through pivot arm 22 and pivot pin 24. The pivot pin 24 is seated in bushing 64 of pivot arm 22 and secured between upper plate 20 and lower plate 21 bearing on shoulder surfaces 69 and 70 which allows a clearance fit to pivot arm 22. The pivot pin 24 is secure to the top plate 20 and bottom plate 21 by retaining plates 65 and 66. A plurality of bolts 67 securing plate 65 to top plate 20 and plate 66 to lower plate 21 and a plurality of bolts 68 securing upper plate 65 and lower plate 66 to pin 24. The bore 71 through pin 24 is provided so that the spring supporting mechanism 300 for the bidirectional backup tool 10 (FIG. 1) to be attached to a power tong 310. A bar 313 through bore 71 with a clearance fit extends through bidirectional backup tool 10, and a compression spring 316 is secured to that bar by plates 314 and 315 adjusted and retained by nut 317 on threads 318, so that the backup tool may deflect axially on the pipe as the threaded joints are coupled or decoupled. The top end of bar 313 is pivotally attached by pin 312 to adapter plate 311 welded to or made a part of power tong 310. Two bars 313 and spring assemblies are used, one on each side of pipe 33. The suspension system may be any conventional system.
FIG. 4 shows the insert 34 retained in the active jaw 26 by dove tail groove 26a. Surfaces 58 and 60 are designed to allow insert 34 to side radially into the active jaw 26. The surfaces 57 and 59 of insert 34 engage the surfaces 58 and 60, respectively, to retain the insert 34 within active jaw 26. Inserts similar to insert 34 are retained in active jaw 27 and reactive jaw 28. All the inserts may be changed without removing the jaws. Active jaw 26 secured around jaw pin 29 and is retained by retainer rings 61 and 62. Jaw pin 29 preferably has bushing 63. Other mechanical means may be used to retain the inserts within jaws.
As shown in FIG. 5, roller 43 is secured by roller pin 50 and retained by retainer ring 50a. Roller 43 is mounted in a slot 73 in pivot arm 22, and roller 43 has a clearance fit within the slot 73. Roller 44 uses the same arrangement as shown in FIG. 5.
Inserts 38, 39 may need to be changed so that a different force angle A (FIG. 1D) can be utilized to either increase or decrease force on the pipe 33. Optionally, load block 37 may have a projections 75 which slide in grooves 74 along the centerline of pipe 33 to provide additional control of load block 37 during the stroke of fluid cylinder 40. Although not necessary, load block 37 may have projection 75 on the top or bottom, or both top and bottom. Projection 75 would then have corresponding grooves 74. Inserts 38 and 39 of load block 37 have a clearance sliding fit between top plate 20 and lower plate 21.
Referring back to FIG. 2, it will be noted that jaw assembly 19, which is a reactive jaw, may be used in all three gripping jaws; one to pivot arm 22, one to pivot arm 23, and one in the throat 19a attached to top and bottom plates 20 and 21 as shown in FIG. 2. This arrangement would be used where equal gripping on the pipe 33 is not an absolute requirement. Any combination of jaw assemblies 14, 15, 16, 17, 18, 19 or 20A may be used on any backup tool or power tong.
Backup tool 11 shown in FIG. 7 is a modification of backup tool 10. In backup tool 11 pivot arm 22 and pivot arm 23 are actuated by movement of rollers 43 and 44 in a different manner than backup tool 10. For example, backup tool 11 has a fluid motor 76 which is used to push force loading block 86 from position 85 toward the pipe and to pull force loading block 37 from position 86a away from the pipe 33. Fluid motor 76 is attached to force loading block 37 using an adapter 95. The spline 77 of fluid motor 76 engages drive shaft 78 which contains a buttress or acme-type thread 79 engaging threads 94 within the threaded bore 86b of force block 86. When fluid motor 76 rotate drive shaft 78 threads 79 on shaft 78 push force block 86 toward the pipe 33 so that roller 43 is pushed into engagement position along ramp 88 until roller 43 contacts force block 86 at position 89. When roller 43 touches force block 86 at position 89, force block 86 engages and pushes crosshead 93 along surface 91. Crosshead 93 supports active jaw 99 or other jaw assemblies described herein which is pushed by force block 86 into pipe 33, forcing pipe 33 into reactive jaws 97 and jaw 98. The force exerted by threads 79 and the force block 86 against crosshead 93 is predetermined and sufficient to hold the pipe 33 from rotation. When force block 86 is pushed against crosshead 93, the reactive force through thread 79 is taken by thrust roller bearing 82 which is forced against boss 96 on shaft 79.
In FIG. 7 top plate 20 is not shown for ease of illustration. Body members 92 and 92A are positioned between top plate 20 and lower plate 21 as an integral part thereof. Crosshead 93 slidingly fits between body or frame members 92 and 92A.
Drive shaft 78 is contained in body or frame member 84. The fluid motor adapter 95 contains grease seal 81 and a zerk fitting (not shown) is used to inject grease into bearings 82 and 83.
In FIG. 7 the force block 86 is shown in the gripping position 86 and has moved up from position 85 into the actuated gripping position 86a. Force block 86 could be actuated by a fluid cylinder pushing force block 86 back and forth rather than the fluid motor 76.
FIG. 8 shows an alternate structure, for causing arms 22 and 23 to pivot outward and force engagement of the active jaws 26 and 27 on the pipe 33. The tool illustrated in FIG. 8 uses a toggle arrangement 12 wherein a traveler toggle block 106 is shown in the retracted position and in the load position 110 (dotted lines). Toggle link 107 is connected at one end to toggle block 106 by pin 108 and connected to pivot arm 22 by pin 109. Toggle link 107 is shown in the retracted position and as in the actuated gripping position 112 (dotted lines). Toggle block 106 in conjunction with toggle link 107 comprise a toggle joint.
Full gripping force is applied by virtue of force F5 which may be applied by a screw thread as in FIG. 7 or by a fluid cylinder which pushes or pulls it from left to right as in FIG. 1. When toggle block 106 is pulled to the right, it is stopped by frame members 114 and 115 Frame members 114, 115 are permanently attached to the top and bottom plates 20 and 21 with toggle 107a forming angle B which is anywhere from one (1) to perhaps fifteen (15) degrees. After force F4 is determined in the same manner as force F3 in FIG. 1D, then force F5 (which is the force required to be applied to shaft 113 by the fluid motor or fluid cylinder 76) is determined by multiplying the tangent of angle B times the force F4 times two for the total pull required by force F5. The fluid cylinder size or fluid motor screw arrangement, if used, can then be determined.
The combination of the toggle block 106 and toggle links 107 also constitutes a force multiplying device. The force applied by the jaws to pipe 33 is substantially greater than the force to pull toggle block to gripping position.
FIG. 9 illustrates a modification of backup tool 10 wherein load block 130, which is similar to load block 37, is actuated by fluid motor 117 which pulls load block 130 to actuate pivot arms 22 and 23. The forces involved in pulling the load block 130 to put the desired force against rollers 43 and 44 is calculated the same as disclosed in connection with backup tool 10 (FIG. 1). Fluid motor 117 is attached to adapter 118 which contains roller bearing 122 and grease seal 124. The flange 121 on shaft 119 bears against thrust bearing 120. Grease is retained by grease seal 123 and zerk fittings (not shown) are provided to grease bearing 120. The threaded portion 128 of shaft 119 is buttress type or acme-type thread.
Fluid motor 117 turns threaded portion 128 of shaft 119 in mating thread 129 inside of load block 130 to pull load 130 into the actuated position. The other end of shaft 119 contains a bearing 125, a retainer ring 126 and a grease seal 127 with means (not shown) to grease the bearing. This is housed within a portion of the body 9 of the backup tool 10 which connects top plate 20 and bottom plate 21 as described in connection with FIG. 1. Backup tool 13 may use any of the jaw configurations backup tool 10 would use.
FIG. 10 shows a jaw assembly 14 which contains a jaw base 131 bolted to pivot arm 22 by bolt 132. Dowel 133 is pressed into jaw base 131 and loosely fits into hole 140 in jaw segments 130. The loose fit of dowel 133 in hole 140 allows jaw segment 130 to roll slightly either on a flat face of jaw base 131 or on a curvature slightly larger than the outside radius of jaw segment 130. This allows some small alignment with pipe 33 outside diameter to make up for irregularly shaped cross section on pipe 33. Insert 34 is retained within jaw segment 130 by mechanical means. One arrangement of jaw assembly 14 which may be used is shown in FIG. 10. Jaw segment 130 is loosely retained by clip 134 which fits over the projection 136 from jaw segment 130 and projection 137 from jaw base 131 and is secured by bolts 135. Being loosely retained, jaw segment 130 may rotate slightly on surfaces 139 or 138 (FIG. 9). This arrangement secures jaw segment 130 top and bottom.
FIG. 11 shows a jaw assembly 15 which is designed not only to adjust to the pipe outer surface, but also to align itself axially with the pipe 33. In jaw assembly 15, the jaw base 143 is rotatably associated with jaw segment 141 by the steel ball 142 which is contained within hemispherical recess 146 in jaw segment 141 and hemispherical recess 147 within jaw base 143. It is necessary in machining hemispherical recesses to have relief hole 144 and relief hole 145. Here again, jaw segment 141 is retained in the same manner as jaw assembly 14 in FIG. 10. Ball 142 bears both radial and torque loads. Means for applying lubricant to ball 142 are provided (not shown). In some cases, it may be desired that ball 142 be permanently secured to either jaw segment 141 or jaw base 143 so that the wear is only on one part.
FIGS. 12 and 13 show jaw assembly 16. Assembly 16 provides radial alignment with irregular pipe shapes by virtue of jaw segment 148 rocking on flat surface 154 or concave surface 155 which is slightly larger than outside radius of jaw segment 148. The jaw segment 148 is loosely retained radially by clip 150 which overlaps the lug 151 on jaw segment 148. Torque loads are retained in one direction by projection 152 on jaw base 149 and in the opposite direction by projection 153 in jaw base 149. These engage lug 151 which is attached to jaw segment 148. Jaw base 149 is connected to pivot arm 22 in the same manner as shown in FIGS. 10 and 11. The retaining means would be on the top and bottom of jaw segment 148.
FIGS. 14 and 15 show a jaw assembly 17. Jaw segment 156 is rotatably mounted to jaw base 157 by a cylindrical dowel 158 which fits into semicylindrical groove 163 in the jaw segment 156 and semicylindrical groove 164 in jaw base 157. This allows radial movement to align with pipe 33 during the gripping process. Jaw segment 156 is loosely retained by clips 162 which fit over projection 160 from jaw segment 156 and projection 161 from jaw base 157. Clips 162 are held in place by bolts 135. The dowel pin 158 absorbs both compressive loads and torque sheer loads developed by the gripping system. Lubrication means (not shown) is provided to dowel pin 158.
FIG. 16 illustrates a jaw assembly 500 which will work for both open and closed throat power tong gripping systems. This assembly includes a drive gear 527 driven by roller chain or gear teeth with bearings 770 between drive gear 527 and a suitable conventional housing 771 driven by one or two fluid motors (not shown) as described in U.S. Pat. No. 5,172,613.
Drag ring 528 rotates concentric with drive gear 527. Drag ring 528 provides resistance in both rotary directions.
Cam roller 531 rolls along cam surface 535 when drive gear 527 is rotated clockwise to bring jaw 533 to pipe 536. Replaceable friction inserts 534 lie between pipe 536 and jaw 533 to handle different pipe sizes. Likewise, cam roller 531 rolls along cam surface 543 when driven in the opposite direction.
The jaw 533 and insert 534 are the same arrangement as jaw assembly 18 in FIGS. 2 and 4 and pivot about pin 532. Jaw link 530 and 530A (on far side of drag ring 528) and cam roller 531 also pivot on jaw pin 532. The opposite ends of jaw links 530 and 530A pivot on pin 529 near side and 529A far side of drag ring 528. Leg 544 on either or both jaw links 530 and 530A operate with spring 545 to urge jaw assembly 500 to a retracted position where cam roller 531 and jaw is urged into recess 546. Recess 546 may be of irregular shape to accomodate to cam roller 531 533 in the retracted position.
In designing the cam geometry shown in FIG. 16 for proper grip on pipe 536 the following steps are followed:
First: As shown in FIG. 16B the total gripping force FRT is determined by taking the smallest pipe diameter 536 to be torqued. Pipe tangential force FTP is calculated as the maximum torque selected divided by the radius 542 of pipe 536.
Second: A gripping factor between 1.2 and 15 is selected which will not allow the jaw assemblies to slip on the pipe under torque loads. For example, a grip factor of four works well on 23/8 inch O.D. pipe for a selected torque of 5,000 foot pounds with proper tooth pattern explained later. This means that FTP times 4 equals FRT the total radial force required in this case to group the pipe. (Grip factor is FRT÷FTP).
Third: A torque force factor FT is calculated as the selected torque in inch pounds divided by the distance from the point cam roller 531 touches cam surface 535 to center point 540.
Fourth: To find force angle C, the tangent of FT divided by FRT gives the force angle C in degrees. This angle will be between 1 degree and 15 degrees. Usually a force angle C of 4 to 6 degrees works well depending on pipe size, selected torque and tooth pattern.
Fifth: To design a cam surface L1 with a selected force angle C, construct a right triangle where the hypotenuse equals L1 and the side opposite angle C is designated H2. Solving this triangle, force angle C=sine (H2/L1).
Sixth: Divide FRT by the number of cam surfaces to determine the radial force FR for each jaw assembly. These are called "active jaws."
The optimum number of cam surfaces and jaw assemblies is three, although this quantity may vary.
Jaws which do not apply gripping force from cam surfaces are called "reactive jaws." Any combination of active jaws and reactive jaws may be utilized.
In FIG. 16 a rigid jaw where the jaw links are integral with the jaw (not shown) may be used where a pivoted jaw is not wanted. This rigid jaw would have replaceable inserts 534 also.
FIG. 16A shows a drive gear 527 with three cam surfaces 551, 552 and 553 as described in FIG. 16. This drive gear allows three active jaw assemblies 500 and an open face tong where pipe is inserted from the side through opening 548. This opening 548 does not exist in a closed face tong where pipe is inserted axially through the cam ring. (Drag ring 528 not shown).
When drive gear 527 is rotated in either direction all jaw assemblies 500 are brought to the pipe simultaneously and the drive gear 527 applies radial force to the pipe. Spring 545 returns jaws assemblies 500 to the retracted position when opening 548 and drag ring 527 are aligned to receive the pipe 536 through opening 548.
Angles 549 and 550 to center line of each cam surface each maybe from zero degrees to 55 degrees depending on clearance within the tong to receive pipe 536. 15 degrees to 35 degrees works best in most cases.
It can be appreciated that jaw assemblies 500 and cam surfaces 551 and 552 can be active jaws and the throat jaw in cam position 553 can be an may be a reactive jaw.
Drag ring 528 may be restrained by conventional brake bands or hydraulic drag means as described in U.S. Pat. No. 5,172,613.
FIG. 17, 17A, 17B and FIG. 18 illustrate a backup tool 22A which is capable of gripping many sizes of pipe between tubular 166 and tubular 165 (illustrated in broken lines). Backup tool 22A has a unique gripping system comprising jaw assembly 20A which provides a gripping force in proportion to the applied torque to tubular 166 and intermediate diameters up to tubular 165. Backup tool 22A has a frame or body 171 with a projection arm 174 which is supported from the tong bracket or support 175 and arm 174 has a shaft 177 on which roller 176 rotates. The shaft 177 has a flange 178 which retains roller 176 on shaft 177.
Once installed, the backup tool 22A grips in one direction. Accordingly, to permit backup tool to grip in the opposite direction, the backup tool 22A is pulled away from support 175 so that roller 176 on shaft 177 seats in support 175. Backup tool 22A is then rotated 180° and pushed back into the support 175 for gripping in the opposite direction. Flange 178 keeps the tool from being pulled completely through support 175. It will be appreciated by those skilled in the art that any type of support from the power tong can be utilized so long as arm 174 may be held in one position and move 180° to the opposite position.
Jaw assembly 20A has jaw member 167 attached by pivot pin 168 to pivot cranks or arms 169 and 169a. Jaw assembly 20A is actuated by pivot arms 169 and 169a between pivot pin 168 in the jaw member 167 and pivot 170 in the frame or body 171. Pivot arms extend out to pin 210 and 210c which are, respectively, at one end of fluid cylinder 173 on top and fluid cylinder 173A on bottom. The opposite ends of cylinders 173 and 173A are attached to body 171 by pins 210a and 210b . Sometimes only one fluid cylinder may be sufficient. In FIG. 17B, jaw assembly 20A is shown in the retracted position 180 and the retracted position of pin 210 is shown as 179. When jaw assembly 20A is retracted as shown by position 180 and pin 179, fluid cylinders 173 and 173A are pulled to position illustrated in FIG. 17B. This allows one of the pipe sizes from tubular 166 to tubular 165 access to the throat 23A of the backup tool 22A.
In operation, tubular 166 or tubular 165, or any size in between, is placed in throat 23A as shown in FIGS. 17 and 17A. The jaw segment 209 is rotatably mounted in the jaw support 188. The radius of jaw segment 209 to jaw support 188 is equal to or less than the radius of the smallest diameter pipe to be used as with a larger radius it would tend to slip with the smaller size of pipe. To set the backup tool 22A for operation, the jaw support or pivot arms or cranks 169 and 169a are positioned approximately as shown in FIG. 17 and a dowel pin 172a is dropped into hole 172 at the point where the cylinders 173 and 174A push pivot arms 169 and 169a into engagement with dowel pin 172a. Angle 208 is predetermined such that when the preload of cylinders 173 and 173a are placed on pivot arms 169 and 169a, respectively, and it has been found that angle 208 may be between 2 and 25 degrees and preferably between 10 and 15 degrees and pivot arms 169 and 169a are forced to rotate around pin 170 counterclockwise and restrained by pin 172a.
Acme or buttress threaded shaft 200 is turned by crank 201 in the threaded portion 211 of body 171 which rotates shaft extension 203 retained by pin 204 in the groove shown with the jaw base 188. The load between the threaded shaft 200 and the jaw base 188 bears on surface 207. Crank 201 is turned, translating jaw base 188 towards jaw member 167 until the proper size pipe is snug between large inserts 190 and 193 or small inserts 191 and 192 in jaw segment 209 and large inserts 181 or 184 or small inserts 182 and 183 in jaw member 167, respectively.
When either the large or small inserts are firmly compressed against the pipe 166, 165 or the size in between, the lock nut 202 is secured on shaft 200 abutting body 171 so that the position is maintained. At this point, fluid cylinders 173 and 173a are retracted, releasing pin 172a so that the pivot arms 169 and 169a and jaw assembly 20A are fully operational. Angle 208 on pivot arm 169 is determined to provide the proper preload since the cylinders 173 and 173a do not provide the full gripping force but only preload. As the pipe tends to rotate clockwise with the applied torque from the power tong near and above the backup tool 22A, pivot arm 169 tends to rotate counterclockwise reducing angle 208 which increases the force of jaw member 167 on the pipe being gripped. To eliminate over travel, surface 224 of jaw member 167 is designed to stop against surface 225 on the body 171 where angle 208 approaches zero degrees. A second method which may be utilized to prevent over travel, lug 226 projecting from the pivot arm 169 contacts surface 227 as angle 208 approaches zero.
Jaw assembly 20A as shown has four inserts 181,182, 183 and 184 for gripping the pipe and jaw assembly 21A as shown has four inserts 190, 191, 192 and 193 for gripping the pipe. Each of these inserts is cylindrical on the portion away from the pipe and has teeth on the portion engaging the pipe. For gripping several small sizes of pipe, inserts 182 and 183 and 191 and 192 are engaged (see FIG. 17A). For gripping larger sizes of pipe inserts 181 and 184 are utilized as well as inserts 190 and 193. The radius to the tips of the teeth of inserts 182, 183, 191 and 192 are approximately the same as the outside radius of the smallest tubing to be gripped within the small size range. The radius to the tips of the teeth of inserts 181, 184 and 190 and 193 conform to the smallest pipe to be gripped within the large size range.
Cylindrical gripping inserts 181, 182, 183 and 184 are retained by a plate 185 secured by bolts 186 and 187 to jaw member 167. Likewise, cylindrical gripping inserts 190, 191, 192 and 193 are retained by plate 194 secured by bolts 195 and 196 to jaw segment 209. Jaw segment 209 is maintained in a central position by springs 198 and 199 which bear against the jaw base 188 on each side of the two flat sides of threaded screw 206.
Referring to FIG. 18, the jaw segment 209 is retained within the jaw base 188 by top and bottom projections 194A from cap 194 which extends into a groove 194B in jaw base 188 loosely fitting to retain jaw segment 209 in operational integrity with the jaw base 188.
FIG. 19 shows generally cylindrical gripping die 181 with teeth 254 and a cylindrical body 181a which fits into cylindrical surface 258. This arrangement is illustrative of the dies in jaws 167 and 209. The dies are relatively loose fit because of the corrosion involved in the operation of power tongs and backup tools. Threaded portion 256 (one or more holes in cylindrical die 181) is placed over a roll pin 257 to limit rotation. The teeth 254 are in the shape of an arc 255, equivalent to the smallest diameter pipe O.D. to be gripped by this particular die which maybe several sizes. The teeth match the smallest diameter so that when larger diameters are used in the same die, the points that touch the pipe outside diameter are shown as teeth 259 and 260. This prevents the tendency for the pipe 165 to roll out of the cylindrical die 181. Threaded portion 256 serves as a means of holding the cylindrical die 181 in a fixture for machining the teeth 254. Referring to FIG. 18, cylindrical die 181, as well as the plurality of cylindrical dies, are held in position by cylindrical boss 261 at each end of die 181 concentric with the diameter of die 181 and the other cylindrical dies. These two bosses 261 fit in loosely fitted holds 264 in top and bottom plates 185, if both are used. This is the same to hold all the cylindrical dies in jaw 167 and jaw 209. Roll pins 257 are embedded in jaw 167 to limit movement of the cylindrical dies 181, 182, 183 and 184. Roll pin 257 will hit either side of tapped hole 256 so that the pivoting of the cylindrical dies with the controlled. This is the same arrangement for all dies in jaw 209.
An alternate jaw 25A is shown in FIG. 20. Jaw 212 has four flat surface recesses 220 in which arcuate backs of inserts 218, 215, 216, and 219 rock on the flat surface of recesses 220 to assure alignment with different pipe diameters. The operation of jaw assembly 25A is the same as assembly 20A. Any combination of cylindrical tooth dies and flat tooth dies may be utilized as desired. The pivot arm 169 is shown on the near side of body 171, and the far side at arm 169a is connected by pin 170. Likewise, pin 168 through jaw 167 is through both pivot arms 169 and 169a.
As best seen in FIG. 20, inserts 215, 216, 218, and 219 are loosely restrained within recesses 200 by dovetail bevels 222, 223, and are retained therein by plates 185 and 194 as seen in FIG. 17. Pivot arms 169 and 169a would attach to pin 213 similar to the arrangement in jaw assembly 20A.
Referring now to FIGS. 21, 22 and 23, another embodiment of a backup tool in accordance with the present invention is illustrated. Bidirectional backup tool 10A comprises a frame or body 9 formed by spaced top and bottom plates 20 and 21. Pivot arms 22 and 23 are pivotally secured to the body 9 by pivot pins 24 and 25, respectively. The above description in connection with FIG. 3 applies to the manner in which the pivoting pins are attached to top plate 20 and lower plate 21 and to pivot arms 22 and 23. Active jaws 26 and 27, and reactive jaw 28 are positioned within the bidirectional backup tool 10A with active pivoted jaw 26 attached to pivot arm 22A by jaw pin 29. Active pivoted jaw 27 is attached to pivot arm 23A by jaw pin 30. The rest of assembly 10A is same as assembly 10 except FIG. 5 and 6 would not apply. Assembly 10A could also be actuated by fluid motor per assembly 11.
The embodiment of FIGS. 21 and 22 comprises a force roller assembly 400 with replaceable rollers 401 and 402 which engage inclined or arcuate cam surfaces 404 and 403 on arms 22A and 23A which establishes a cam-like or ramp face. By actuating fluid cylinder 50 (the rod of which is threaded into roller assembly 400), roller assembly 400 is pulled to the right, causing the pivot arms 22A and 23A to pivot around the pivot pins 24 and 25 so that active pivoted jaws 26 and 27 of pivot arms 22A and 23A are moved into engagement with pipe 33. Initially, hardened rollers 401 and 402 of roller assembly 400 engage hardened cam surfaces 403 and 404 of pivot arms 22A and 23A which moves active jaws 26 and 27, respectively, snugly against pipe 33. Then cam surfaces 403 and 404 engage rollers 402 and 401 and pivot arms 22A and 23A rotate about pivot pins 24 and 25. Cam surfaces 403 and 404 may be replaceable hardened inserts attached to arms 22A and 23A.
The embodiment of FIGS. 21, 22 and 23 may be actuated as described for FIGS. 7 and 9. The pivoting of arms 22A and 23A applies force through active jaws 26 and 27 against the pipe 33 abutting reactive jaw 28 in proportion to the amount of force applied by fluid cylinder 40. To release the pipe 33, roller assembly 400 is pushed by fluid cylinder 40 to the left into the retracted position 47. By an extension spring 48 attached to pivot arms 22A and 23A, rollers 401 and 402 are biased to engage surface 404 and 403. This enables the pivot arms 22A and 23A to work active jaws 26 and 27 in and out of engagement with pipe 33 abutting reactive jaw 28. All other aspects of FIGS. 21 and 22 are same as FIGS. 1, 1A, 1B, and 1C.
The combination of the rollers 401 and 402 and arcuate cam surfaces 403 and 404 also comprise a force multiplying device. Once again, this is because the force applied to pipe 33 is substantially greater than the force required to pull the rollers along the arcuate cam surfaces into a gripping position.
FIG. 23 is a schematic drawing showing the curved cam 403 and arm 22A which pivots about pin 24. The required torque 412 is determined from the predetermined gripping force F1 on jaw 26 multiplied by the distance from jaw pin 29 and arm pivot 24.
Arm 22A position 410 with roller position 402 a distance 405 from pin 24 is the position with pipe 33 at its largest acceptable diameter. Arm 22A position 412 with roller portion 402A a distance 406 from pin 24 is the position with pipe 33 at its smallest acceptable diameter.
To convert actuator 40 or 76 pull force 409 to torque 412, force 410 in roller position 402 is determined by dividing torque (in lbs) by distance 405. Since we now know force 409 and force 411 we can determine angle 407, the tangent of which equals force 409 divided by force 410.
This procedure is done for several increments of distance between distance 405 and 406. The served calculated angles between angle 407 and 408 can be plotted to determine the curved cam surface 403 which will provide the same force F1 on jaw 26 regardless of position of roller 402 between distance 405 and 406. This is true of the cam surface 404 on arm 23A and cam roller 401.
It is important that due to large stresses created between rollers 401 and 402 on cam surfaces 403 and 404 these components should be a steel heat treated to Rockwell 15 to 76 on the "C" scale. Rockwell C-37 to C64 is an acceptable hardness range.
Although the invention has been described in conjunction with specific forms thereof, many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing disclosure. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herewith shown and described are to be taken as the presently preferred embodiments. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements or materials may be substituted for those illustrated and described herein, parts may be reversed, and certain features of the invention may be utilized independently of the use of the other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. | Apparatus for gripping tubular members including self aligning gripping jaws with high coefficient of friction for resisting force applied to the elongated member to prevent rotation either clockwise or counterclockwise. Linear cams and cam rollers actuated by a fluid cylinder bring the gripping jaws to an elongated member, applying predetermined gripping force and retract the jaws for removal of the elongated member. | 1 |
TECHNICAL FIELD
[0001] The present invention refers to a method of producing a particle or group of particles having a coating of at least two, preferably at least three, outside each other located thin layers of interacting polymers, at which the particle or group of particles is treated in consecutive steps with solutions of the interacting polymers. The particles consists at first hand of fibers or filler particles. Such a coating modifies the properties of the particles as well as the properties of the products, e g paper and nonwoven, in which the treated fibers and/or filler particles are contained.
BACKGROUND OF THE INVENTION
[0002] The increased use of recovered fibers in paper production and the use of components with poorer bonding properties, such as mineral fillers, have increased the need for more effective dry strength agents in the paper. Traditionally two different methods have been used for adding strength improving chemicals to the paper, viz. by adding chemicals at the wet end of the paper process or by surface application by means of a size press. Wet end addition is usually more effective than surface application counted per kg utilized product. In order to maintain the addition made in the wet end in the paper sheet, wet end chemicals are mainly exclusively cationic, and for making them less sensitive to dissolved and colloidal materials and the increased concentration of electrolytes caused by the increased closing of the systems, their cationic charge is usually increased. This leads in turn to a decreased saturation adsorption of the additive chemicals to the fibers, which leads to a reduced maximum effect of the additive chemicals. This involves that there is a need both for new methods of applying strength-improving chemicals to the paper, and new chemical systems.
[0003] Besides there is an increased need for improving the opacity of the finished paper. Since the today most frequently used strength agents contribute negatively to the opacity the need for new methods of developing strength in the paper is further reinforced.
[0004] Such a way would be to utilize size presses to a higher extent, but this would however lead to large reductions of the manufacturing capacity and the production economy since the paper has to be dried once farther depending on the rewet it is exerted to in the size press.
[0005] This involves that there is a great need for new ways of treating fibers and other particles contained in the paper, such as filler particles, in the wet end of the paper machine.
[0006] Also treatment with a similar process such as size presses may be of interest if the quality of the produced paper is herewith increased in a satisfactory way, so that the above mentioned drawbacks will be of less importance.
[0007] It is known to build up thin multilayers of electro active polymers on an electrostatically charged substrate for use in optics, such as sensors, friction reduction etc. This is described in for example in Thin Solid Films, 210/211 (1992) 831-835 and in Thin Solid Films, 244 (1994) 806-809. The substrate is herewith immersed alternatingly in diluted solutions of a polycation with an intermediate rinsing in order to remove rests of the previous polyion which is not bonded to the substrate. The thickness of each deposited layer is described to be between 5-20 Å. There is no indication that the treated substrates could be particles, such as fibers.
[0008] In U.S. Pat. No. 5,338,407 there is disclosed a method for improving the dry strength properties of paper, at which an anionic carboxy methyl guar or carboxy methyl hydroxy ethyl guar and a cationic guar is added to the furnish. These two components are either added in mixture or separately. There is no indication that the treatment is made under such conditions that a double layer is built up on the fibers with one component in one layer and the other component in the other layer.
[0009] In the U.S. Pat. Nos. 5,507,914 and 5,185,062 there are disclosed methods for improving the dewatering properties and the retention of paper by adding anionic and cationic polymers to the pulp. There is no indication that the treatment takes place under such conditions that a double- or multilayer is created on the pulp fibers with the anionic component in one layer and the cationic component in the other layer.
[0010] Dual surface treatment of filler particles with anionic and cationic polymers is disclosed in EP-A-0 850 879, WO 95/32335, U.S. Pat. Nos. 4,495,245 and 4,925,530. There is no indication that the treatment takes place under such controlled conditions that a double- or multilayer is created on the pulp fibers with the anionic component in one layer and the cationic component in the other layer.
The Object and Most Important Features of the Invention
[0011] The object of the present invention is to provide a method for producing particles or groups of particles, especially fibers and/or filler particles, having a coating of at least two, preferably at least three, outside each other located thin layers of interacting polymers, at which the particle or group of particles is treated in consecutive steps with solutions of the interacting polymers. This has been provided by the fact that excess of the previous polymer is removed between each treatment step alternatively that the respective polymer is added only in such an amount in each step that substantially all polymer is adsorbed to the particle surface.
[0012] The particles or groups of particles may be of optional type, however fibers, e g cellulosic fibers, regenerated fibers and different types of synthetic fibers, and filler particles are mainly concerned.
[0013] The interacting polymers are preferably alternating cationic and anionic polyelectrolytes, but they may also be so called zwitter ions.
[0014] The thickness of each of said thin layers is preferably between 3 and 100 Å, more preferably between 7 and 20 Å.
[0015] The invention further refers to a paper- or nonwoven product, which contains fibers and/or filler particles produced by the method described above.
DESCRIPTION OF DRAWINGS
[0016] [0016]FIG. 1 shows in the form of bar charts the tensile strength index of sheets made of cellulosic fibers with different numbers of applied polymer layers.
[0017] [0017]FIG. 2 shows in the form of bar charts the tensile strength index of paper containing different amounts of filler particles treated according to the invention.
[0018] [0018]FIG. 3 shows a tensile strength index-opacity diagram for paper containing different amounts of filler particles treated according to the invention.
[0019] [0019]FIG. 4 shows in the form of a bar chart the increase of tensile strength of paper containing pulp fibers coated with an anionic and a cationic polymer added at the same time and added separately in six consecutive steps rinsing away the excess of polymer between each step.
DESCRIPTION OF THE INVENTION
[0020] According to the present invention particles or groups of particles, e g fibers or filler particles, are treated with interacting polymers in order to build up thin multilayers of the interacting polymers on the particle surface. In principle the technique described in for example above mentioned articles from thin Solid Films is used in case alternating cationic and anionic polyelectrolytes are used as interacting polymers, with the difference that according to the invention the substrate is fibers or other particles or groups of particles.
[0021] The particles are treated in consecutive steps with solutions of the interacting polymers, at which the treatment time for each step is sufficient for forming a layer of the desired molecular thickness, preferably of the magnitude 5-100 Å. The interaction between the particles can be in the form of electrostatic forces, at which the polymers consist of alternating cationic and anionic polyelectrolytes, or by interaction between nonionic polymers by means of e g dispersion forces or hydrogen bonds. Examples of this type of interaction between nonionic polymers are adsorption of polyethylene oxide on unbleached cellulosic fibers and complex formation between polyethylene oxide and polyacrylic acid.
[0022] In case the interacting polymers are alternating cationic and anionic polyelectrolytes the first layer should be a cationic polymer for particles or groups of particles having an anionic surface, which for example is the case for cellulosic fibers, and vice versa. Possible excess of the previous polyelectrolyte can be removed between every treatment step, e g by rinsing with water. Alternatively the addition is controlled in such a way that no excess amount of the respective polymer is added in each step, so that substantially all polymer is adsorbed to the particle surface.
[0023] The method is based on electrostatic attraction between oppositely charged polyelectrolytes for building the desired multilayers. By treating the fibers in consecutive steps with a solution containing polyions of opposite charge and permit these spontaneously to adsorb to the particle surface, multilayers of the stated kind are built up. In principle all types of polyelectrolytes may be used.
[0024] Through such a treatment of particles or groups of particles, such as fibers, it is possible to make new types of surface modifications to them. By for example treating fibers with consecutive layers of hydrophobic, charged polyelectrolytes it would be possible for example to develop new types of hydrophobizing chemicals for the hydrophobization of paper. It would also be possible to build up “intelligent” surface layers on fibers, which alter the properties with temperature, pH, salt content etc. These changes could for example be based on fundamental knowledge about modern theories on interaction between polymers and surfactants.
[0025] Further applications are ion-exchanging fibers where “membranes” with ion-exchanging properties are provided on the fiber surface, wet strength agents where the added polymers are reactive with the fibers and with each other, in order to provide permanent bonds between the fibers and for the production of highly swelling surface layers, where the added chemicals form swollen gel structures on the fiber surface for use in absorbent hygiene products. Another possible application are new types of fibers for printing paper, where the adsorbed polymers change colour when they are exerted to an electric, magnetic or electromagnetic field. Such polymers are available today.
[0026] The fibers that are treated with the method according to the invention can be of optional kind, natural as well as synthetic fibers. Mainly cellulosic fiber are concerned. However it would be possible to treat synthetic fibers, for example for giving them a more hydrophilic surface.
[0027] Also groups of fibers or particles can be treated according to the method.
[0028] Examples of suitable anionic and cationic polyelectrolytes which may be used in the method according to the invention are given below.
[0029] Anionic polyelectrolytes: Anionic starch with different degrees of substitution, polystyrene sulphonate, carboxy methyl cellulose with different degrees of substitution, anionic galactoglucomannan, polyphosphoric acid, polymethacrylic acid, polyvinyl sulphate, alginate, copolymers of acryl amide and acrylic acid or 2-acrylic amide-2-alkylpropane sulphonic acid.
[0030] Cationic polyelectrolyte: Cationic galactoglucomannan, polyvinyl amine, polyvinyl pyridine and its N-alkyl derivatives, polyvinyl pyrrolidone, chitosan, alginate, modified polyacryl amides, polydiallyl dialkyl, cationic amide amines, condensation products between dicyane diamides, formaldehyde and an ammonium salt, reaction products between epichlorhydrine, polyepichlorhydrine and ammonia, primary and secondary amines, polymers formed by reaction between ditertiary amines or secondary amines or dihaloalkanes, polyethylene imines and polymers formed by polymerisation of N-(dialkylaminoalkyl)acrylic amide monomers.
EXAMPLE 1
[0031] The example below shows the increase of tensile strength of sheets made in a dynamic sheet former. The pulp that is used was bleached SWK (softwood sulphate pulp) beaten in accordance with SCAN-C 18:65, diluted to 3 g/l and pH adjusted to 8. PVAM (polyvinyl amine), a cationic polymer, was added in excess and was given time to react after which the excess of polymer was washed away from the fiber suspension by means of water. After that CMC (carboxy methyl cellulose), an anionic polymer, was added in excess, and after 10 minutes non-adsorbed polymer was removed through washing. Admixture of PVAm and CMC was repeated in several steps. After each addition of CMC the so called dynamic sheet former was used for making sheets having a basis weight of 80 g/m 2 . The sheets were tested with respect to tensile strength according to SCAN-P 67:93. The results are shown in Table 1 below and proves clearly an improvement of tensile strength index with the number of applied polymer layers.
TABLE 1 Polymer layer (P = PV Am, C = CMC) Tensile strength index (kNm/kg) No polymer 39.0 P 53.6 PC 56.6 PCPC 69.4 PCPCPC 75.8
[0032] The results are also shown in FIG. 1 in the drawings.
EXAMPLE 2
[0033] In this example fillers for papermaking have been used which have been treated through multilayer adsorption with the same polymers as in Example 1 above, i e polyvinyl amine and carboxy methyl cellulose. Paper sheets of 80 g/m 2 were made in a dynamic sheet former. The sheets were tested with respect to ash content, tensile strength index and opacity. The results are shown in Table 2 below. Ash content here means the content of filler treated as above and which has been added to the paper.
TABLE 2 Tensile Polymer layer strength index Opacity (P = PV Am, C = CMC) Ash content (%) (kNm/kg) (%) No polymer 0.0 47.2 78.8 No polymer 20.6 19.7 87.1 P 7.5 38.3 82.9 P 14.3 30.5 86.7 P 21.7 23.8 89.5 PCP 7.5 37.9 83.5 PCP 13.9 31.7 87.8 PCP 24.3 26.6 90.7 PCPCP 9.0 40.0 84.7 PCPCP 18.0 35.9 87.0 PCPCP 28.0 30.0 191.0
[0034] The results are also shown in FIG. 2 and 3 . FIG. 2 shows the effect on strength in the paper containing different amounts of filler particles treated according to the invention. FIG. 3 shows the effect on the opacity of paper when using different amounts of fillers treated according to Example 2 above.
EXAMPLE 3
[0035] Two types of polymers were used: an anionic polyacryl amide (A-PAM), Percol 155 from Ciba, and a cationic polydimethyl diallyl ammonium chloride (DMDAAC) also from Ciba. The pulp that was used was unrefined, fully bleached longfiber pulp, pH 8 in all tests. The dosing of the polymers were done in two different ways:
[0036] A) all at the same time and in this case 3.9 kg/ton A-PAM was added first and then 6.6 kg/ton polyDMDAAC was added.
[0037] B) Six layers of 1.1 kg/ton polyDMDAAC and 0.65 kg/ton A-PAM in the respective layers were added. Excess of polymer was removed between the dosings.
[0038] Handsheets were then made and the strength (tensile strength index) was measured. In FIG. 4 the strength increase in % is shown for the two different cases. As can clearly be seen it is much more effective to add the polymers in layers in a controlled manner. | Method of producing a particle or group of particles having a coating of at least two, preferably at least three, outside each other located thin layers of interacting polymers, at which the particle or group of particles is treated in consecutive steps with solutions of the interacting polymers. Excess of the previous polymer is removed between each treatment step alternatively the respective polymer is added only in such an amount in each step that substantially all polymer is absorbed to the particle surface. It is also referred to a paper- or nonwoven product containing fibers and/or fillers containing particles or groups of particles of the mentioned kind. | 3 |
BACKGROUND OF THE INVENTION
a) Field of the Invention
This invention relates to a new or improved compound fabrication process and apparatus therefor, and in particular to the development of a miniature machine tool for manufacture of micro, high precision components.
b) Description of the Prior Art
In general, conventional machine tools are used to manufacture micro components. Usually the manufacture of such micro components requires multiple machining processes such as micro Electrode Discharge Machining (EDM), micro Electro Chemical Machining (ECM), micro milling, micro turning and micro drilling. Therefore to manufacture a simple part may entail use of more than one machine, depending on the geometry of the workpiece. For example to machine a micron sized hole in a workpiece one may have to first machine an electrode using turning, milling or other processes. The machined electrode will have to be placed in the spindle of an EDM machine to machine the micron-sized hole. During this process, if the electrode is not properly aligned on the spindle with respect to the workpiece there is a possibility of producing an inaccurate hole because of the set-up and machine errors. The prior art does not address the problem of combining multiple processes on a single set-up, but is confined to simple single process machines such as those disclosed in U.S. Pat. No. 3,998,127, U.S. Pat. No. 5,439,431, U.S. Pat. No. 4,706,371, U.S. Pat. No. 4,646,422, U.S. Pat. No. 5,117,552.
The above mentioned references do not cover any method or means for combining conventional processes such as milling, turning, etc. with non-conventional processes such as Electrode Discharge Machining or Electro Chemical Machining. Therefore when conventional and non-conventional processes must be applied in succession there arises the possibility of inaccuracies in alignment of workpieces due to the fact that they have to be repositioned for conventional and non-conventional machining. These problems are particularly acute in the case of micro machining where the dimensional tolerances are very small. To minimize such inaccuracies, the present inventors have appreciated that it would be desirable to perform multiple manufacturing or fabrication processes in a single machine and thus avoid the manufacturing inaccuracies which are inherent in multi-stage processing operations.
SUMMARY OF THE INVENTION
The objective of the invention is to provide an improved fabrication process and apparatus through which multiple manufacturing steps can be performed on a single platform without re-gripping of the workpiece so that very significant improvements can achieved in terms of the dimensional accuracy of the workpiece being produced.
The invention provides a miniature machine tool for performing on a workpiece at least one conventional mechanical machining operation and at least another machining operation selected from electrochemical machining (ECM) and electro deposit machining (EDM); said machine tool including a holder in which said workpiece is clamped during said machining operations; wherein said machine tool is configured to perform said machining operations in succession without intervening reclamping of the workpiece.
For example the machine can be a micro scale universal milling machine in which various conventional forming operations such as turning, milling, drilling, shaping polishing and grinding can be performed as is known, and wherein it is also possible to perform non-conventional machining processes such as Electro Discharge Machining and Electro Chemical Machining. For example the machine tool can be used to manufacture an electrode by known mechanical material removing processes and then used carry out a micro Electro Discharge Machining operation with the electrode. The equipment can also be used to carry out Electro Chemical Machining operations on milled or turned workpieces, or to perform electro discharge manufacturing on workpieces to improve surface finish and accuracy. No machine in the prior art has the capability to perform all the above listed steps on a workpiece.
A preferred apparatus for carrying out the invention comprises a miniature universal milling machine having a machine frame formed by a gantry structure having two spaced vertical pillars connected at their upper ends by a crosshead beam which supports a carriage on which tooling such as a universal milling head can be adjusted horizontally and vertically. A machine bed positioned in a lower part is arranged to be adjustable in a horizontal plane and also vertically. The machine is capable of supporting various driven spindles which can carry tools for performing milling, drilling, grinding etc. operations.
The invention also provides a method of fabricating a workpiece in a miniature machine tool as described above, the method comprising the steps of: providing a workpiece blank and clamping said workpiece blank in said holder; performing a first conventional mechanical machining operation on said workpiece blank; and without re-gripping of said workpiece blank performing a second machining operation therewith, said second machining operation being selected from ECM and EDM.
Typically the conventional mechanical machining operation will be performed on the workpiece first followed by the second machining operation involving ECM or EDM, but in principle the order of these operations could be reversed.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The invention will further be described, by way of example only, with reference to the accompanying drawings wherein:
FIG. 1 is a somewhat schematic front elevation of a miniature machine tool equipped for carrying out the method of the present invention;
FIG. 2 is a right side elevation of the machine tool of FIG. 1 ;
FIG. 3 is a front elevation of the machine tool illustrating a different tooling configuration;
FIG. 4 is a right side elevation corresponding to FIG. 3 ;
FIG. 5 illustrates three further tooling configurations which can be used in the machine tool;
FIGS. 6 , 7 , 8 and 9 are schematic views illustrating mechanical machining operations that can be performed in the machine tool of FIGS. 1 to 4 ; and
FIGS. 10 , 11 and 12 are schematic views illustrating two-stage compound machining operations that can be performed; and
FIGS. 13 , 14 and 15 are views illustrating the manufacture of a component through a series of successive two-stage compound machining operations.
FIG. 16 illustrates the wire EDM attachment that can be used in the machine tool of FIGS. 1 to 4 .
FIGS. 17 and 18 illustrate the operation of the numerical control system and how it is integrated to the machine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1 , a machine tool 10 in accordance with the invention comprises a base frame 12 upon which is supported a pair of beds 14 , 16 each of which is independently moveable under a controlled drive system (not shown) to move in the fore-and-aft direction of the machine tool as indicated by the arrow 18 in FIG. 2 . Each of the beds 14 and 16 as will be more fully explained hereafter forms one component of a machining station for carrying out operations on workpieces.
Rigidly attached to the base frame 12 are a pair of laterally spaced vertical pillars 20 the upper ends of which are rigidly connected to opposite ends of a horizontal crossbeam 22 which spans the width of the base frame as seen in FIG. 1 .
In known manner, the crossbeam provides a horizontal guide for movement of a carriage 24 thereon, this carriage in turn providing guidance for vertical movement of a linear slide 26 therein. The linear slide in turn provides a mounting for various tooling or work gripping components such as the indexing head 28 shown in FIGS. 1 and 2 .
The basic machine tool configuration described above is not disclosed in any detail since it is well understood by those skilled in the art. It will be seen that the indexing head 28 accommodates four replaceable tooling or gripper sets 30 extending at angular intervals of 90° thereon.
In known manner the machine tool includes drive means selectively engageable to apply a powered drive for rotation of a selected one of the tooling sets/grippers 30 when it is desired to perform a mechanical machining process on a workpiece. As is known in such machine tools, the mechanical machining process can be selected from drilling, milling, shaping, turning, grinding, and polishing.
In the machine tool as illustrated in FIG. 3 , the indexing head 28 is replaced by a drill head 32 , and depending upon the requirements it could equally well be replaced by the components shown in FIG. 5 namely (a) a milling head 34 , (b) a polishing head 36 , or (c) a grinding head 38 .
FIG. 1 shows the machine tool 10 configured to perform in succession a turning operation and an EDM or ECM operation. In this set-up the downwardly directed tool holder 30 is configured to grip an electrode workpiece 64 in a power driven rotatable holder 40 to be machined by turning, metal removal being performed by a cutting tool 41 held in a tool mount 42 carried on the bed 16 . By suitable manipulation of the relative positions of the electrode workpiece 64 and the tool mount 42 , a required turning operation can be performed on the electrode workpiece 64 as it is rotated by the holder 40 . Thereafter, while still engaged within the holder 40 , the electrode workpiece 64 can be transferred to the location of a tank 44 (carried on the left hand bed 14 as seen in FIG. 1 ) for the performance therein of an EDM or an ECM operation. The workpiece to be machined by EDM or ECM is placed in the tank 44 and the electrode workpiece 64 is used for machining the workpiece in tank 44 . Separate tanks are used for EDM and ECM operations. For EDM operation, the tank 44 is filled with dielectric medium whereas for ECM operations the ECM tank 44 will be filled with electrolyte. The use of two different delivery systems avoids the possibility of cross contamination.
FIG. 3 shows the machine tool 10 set up to perform a micro milling operation on the workpiece. The milling tool is held in a gripper 35 that is mounted on the linear slide 26 , the workpiece then being brought into the vicinity of the milling tool 37 held in the milling head, the relative positions of the tool 37 and the workpiece W being manipulated as the workpiece is rotated to effect the desired milling operation.
FIG. 6 shows an alternative machining operation wherein the rotating spindle 46 carries the workpiece for machining by the tool 41 .
FIG. 8 shows the rotating spindle 46 carrying a grinding wheel 50 for performing a grinding operation on the stationary workpiece W.
FIG. 9 shows the rotating spindle 46 carrying a polishing tool 52 for performing a polishing operation on the workpiece W.
FIG. 10 illustrates two operations to effect hybrid machining for forming micro holes. In FIG. 10 a the electrode workpiece 64 held in the driven spindle 46 is machined by the turning tool 41 to produce an electrode 54 . In a subsequent step as indicated in FIG. 10 b the electrode 54 is then used in a micro EDM operation to produce a hole in a workpiece W.
FIG. 11 illustrates a milling tool 48 held in the driven spindle 46 and manipulate to cut a desired profile in an electrode 56 . The electrode is then inverted as shown in FIG. 11 b and used in an EDM process to shape the workpiece W.
As shown in FIG. 12 a the spindle 46 first holds an electrode 58 used in an EDM process to act upon a workpiece W. In a subsequent operation as shown in FIG. 12 b the workpiece is further processed in an ECM operation by an electrode 60 .
The hybrid machining operations described in the foregoing in relation to the apparatus shown in the drawings provide the main advantage that they enable the machining of micro components of great accuracy without changing the machine set up. For example an electrode machined by micro turning or micro milling can be further processed by micro ECM (electrical chemical machining) to improve its surface smoothness and dimensional accuracy, and this same electrode can then be used in a micro EDM operation to reconfigure functional components. In these means errors which could otherwise arise due to clamping or set up tolerances can be eliminated.
It will be appreciated that various other hybrid micro machining operations can be performed by combining selected operations to ensure that workpieces are produced with improved dimensional accuracy. For examples FIGS. 13 , 14 and 15 illustrate successive steps in a hybrid machining process for producing in a workpiece W a mould cavity configuration as shown in the right hand view of FIG. 15 . Initially, as shown in FIG. 13 a turning tool 41 is employed to produce the desired dimensions of an electrode 64 that is rotated in the driven spindle 46 . Thereafter this electrode 64 is employed to produce in the workpiece W a preliminary cavity 61 a corresponding to the profile of the electrode.
Subsequently, as shown in FIG. 14 , without removing the electrode 64 from the spindle 46 , the lower end of the electrode is rounded as at 64 a by the turning tool 41 , where after the spindle 46 is used to transfer the modified electrode to produce by an EDM process rounded depressions 65 providing a modified recess 61 b in the workpiece W.
In a further stage as shown in FIG. 15 the turning tool 41 is again used to reconfigure the electrode 64 to provide a small diameter extension 67 . This extension 67 is then used as shown in the right hand part of FIG. 15 to produce by an ECM process a central hole through the workpiece W.
As depicted in FIG. 16 , a portable wire EDM 100 can be attached to the spindle 46 . The wire EDM 100 is driven by a motor which makes the wire move around. The attachment can be tilted to any angle in order to produce slots of any angle. One such arrangement to produce a slot using the wire EDM attachment is shown in FIG. 16 .
Movements of the various components of the machine tool are driven under a program provided by a central processing unit connected to a numerically controlled system which can be designed to carry out various hybrid machining processes in predetermined combinations. FIGS. 17 and 18 are flow-charts showing the system logic for numerically controlled machining.
Briefly stated, the machine tool and the processes described above deliver at least the following advantages:
1. By virtue of the gantry structure of the micro machine tool the stability of the various components in the machine is enhanced and the dimensional accuracy of resulting workpieces is therefore improved. 2. The described system provides the capability to machine micro components using conventional and non-conventional hybrid machining processes which can include two or more of the following: micro milling; micro turning; micro EDM; micro ECM; micro polishing; and micro grinding, all performed on the same machine tool. 3. The system provides the capability of manufacturing non-cylindrical EDM and/or ECM electrodes in the single tool. 4. The system provides the capability of using EDM or ECM electrodes produced therein without changing the machine set up. 5. The system provides the capability of performing wire cut EDM using a portable attachment. | A miniature machine tool for micro-machining is capable of performing on a workpiece at least one conventional mechanical machining operation and another micro-machining operation such as electrochemical machining (ECM), electro deposit machining (EDM), micro-milling or micro-turning or micro-drilling. The machine tool includes a holder in which the workpiece is clamped during all successive machining operations so that the machining operations may be performed in succession without intervening reclamping of the workpiece. This increases dimensional accuracy when micro-machining high-precision components. | 8 |
FIELD OF THE INVENTION
This relates to the field of articles having lids and more particularly to electrical junction boxes containing connections of service wires and telephone distribution cable.
BACKGROUND OF THE INVENTION
There are several commercially utilized connectors for providing interconnection between individual wires of service lines for customers to the main distribution cable of a telephone utility company in an enclosure or junction box, usually by means of an intermediate stub cable. The enclosure can be mounted in a ground level pedestal, or within a building, or mounted on an outside wall or a pole. Such enclosures which are for outdoor use must protect the connections from the environment, such as from precipitation, dust, insects, rodents and the like. One example of such an enclosure is sold by AMP Incorporated, Harrisburg, Pa. under Part No. 769164 as AMP Quiet Front Pole Mount Terminal, adapted for connection of up to 25 pairs of service wires. Another example of enclosure is also sold by AMP Incorporated, AMP Quiet Front Terminal Closure having Part No. 769147-1 for connection of up to six pairs.
One example of connector for mounting within enclosure is disclosed in U.S. Pat. No. 5,006,077 in which terminal blocks include silos within which are contained respective barrel terminals already terminated to conductors of the distribution cable and are apertured to receive ends of service wires inserted thereinto for termination thereto to define the electrical connection.
In several types of junction boxes for such connectors, overvoltage protector elements are provided on the circuits which protect the circuits of the customer's equipment from energy surges, such as from lightning strikes and the like. Several examples of such protectors are disclosed in U.S. Pat. Nos. 4,158,869; 4,161,762; and 4,133,019. Modules containing such protectors are disclosed in U.S. Pat. Nos. 4,742,541; 4,159,500; 4,613,732 and 4,675,778. The telecommunications industry has established standards for performance and certain dimensional and design requirements for such protectors; one example is Bellcore Technical Reference No. TR-TSY-000070, Issue 1, February, 1985, entitled "Customer Station Gas Tube Protector Units".
It is desired to provide a module containing an array of such protectors which can be assembled within an enclosure such that each protector is electrically connected in-line for the circuits interconnected by the terminals of the terminal block contained within the enclosure, upon termination of a service wire to a terminal.
It is further desired that such protector module be sealed against moisture.
It is also desired to provide such a protector module with an openable lid secured to the module's housing.
SUMMARY OF THE INVENTION
The present invention is a system of securing a lid onto a housing, such as for a module containing an array of protectors removably contained therein, where the module includes a housing of dielectric material defining protector-receiving cavities into which respective protectors are insertable. Such a protector module is disclosed in U.S. patent application Ser. No. 07/863,626 filed Apr. 3, 1992 and assigned to the assignee hereof.
The module includes a ground plate disposed across the upper face of the housing body to become electrically engaged with a ground electrode of each protector. At least a first contact is mounted proximate the bottom of each cavity and includes a first contact section exposed within the cavity for electrical engagement with a corresponding active electrode of a respective protector. The first contact includes a deflectable arm extending to an enlarged tab disposed transversely near the bottom of the cavity and slightly upwardly therefrom to be engaged by the active electrode protruding from the bottom of the protector establishing assured electrical engagement therebetween with the tab being deflectable downwardly toward the cavity bottom, which assures spring biased electrical engagement with the protector's active electrode. The contact is easily terminatable to an associated conductor wire of a stub cable to which the enclosure is being assembled and to a corresponding terminal for the circuit to be protected by the protector by having an end portion exposed along or extending from the bottom face of the module housing, defining a second contact section.
A lid of the housing is easily openable for access to the protectors for servicing, self-retains on the housing body upon being opened, and establishes a watertight seal with the housing body upon being closed. The lid is adapted to seal around the entire periphery of the housing body upon being closed, by including a resilient downwardly extending peripheral flange having inner and outer wall sections defining an upwardly extending channel therebetween canted outwardly. The peripheral flange is forcefittable over a corresponding upwardly and outwardly projecting lip around the upper edge of the side walls of the housing body forming a snug fit therewith.
The lid of the present invention is secured to the housing body by a pair of tabs extending downwardly along the outer side wall of the housing body and through slots of projecting ledge portions integrally molded with the housing body. The tabs have laterally extending latches along side edges thereof proximate the free ends having upwardly facing latch surfaces which prevent the tabs from being-pulled upwardly through the ledges once inserted therethrough, retaining the lid to the housing body. The free ends of the tabs can also be molded to extend rearwardly at a right angle to the latches, enabling the lid to be lifted when opened until the free ends engage the bottom surfaces of the ledge portions so that the lid may be easily pivoted backwardly while still remaining secured to the housing body, freeing access to the protector array from interference. Outer edges of the tabs preferably are tapered at the free ends facilitating insertion through the slots during attachment of the lid.
It is an objective of the present invention to provide a module containing surge protective devices, with the module adapted to provide for interconnection with conductors of a stub cable and conductor lengths extending to terminals of a terminal block, defining a unitary assembly adapted for field connection of service wires to the stub cable in an enclosure.
It is also an objective for such a protector-containing module to accept commercially available protectors of several similar designs.
It is a further objective to provide effective sealing of such protector-containing module by providing an openable lid secured to a housing of the module in a manner permitting field replacement of the protectors, if necessary.
It is also an objective to provide a lid for a protector-containing module which is adapted to remain attached to the module after being opened, and remain opened in a position to provide clear access to the protector array during servicing.
It is additionally an objective for such lid to be an integrally molded article pivotably attachable to one side of the module housing at complementary securing means integral with the lid and with the housing respectively.
Embodiments of the present invention will now be discussed by way of example with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a protector module of the present invention assembled to a corresponding terminal block, with the lid of one shown open exposing several protectors in position, and a stub cable and representative customer line assembled thereto;
FIGS. 2 and 3 are partial cross-section views of the protector module showing the lid in open and closed positions respectively;
FIGS. 4 and 5 are isometric views from rearward and below the protector module housing body showing the lid being assembled thereto; and
FIG. 6 is an enlarged view of a lid tab latched in a housing slot.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is illustrative of a completed enclosure 10 containing a terminal block 12 within an enclosure housing, and a protector module 50 also assembled therewithin, all electrically connecting conductors of stub cable 14 to discrete customer lines such as representative line 16 to provide telephone service between a central office and the customers. Terminal block 12 includes a plurality of paired discrete housing sections 18,20 within which are disposed respective terminals interconnecting respective wires 22,24 of customer lines 16 with respective conductors of stub cable 14. One or more of customer lines 16 may be protected against voltage surges by protectors 150 contained within protector module 50 and electrically connected to the circuit comprising the customer line and the conductors of the stub cable. Protectors 150 are in grounding engagement with ground plate 54 secured across the top of dielectric housing 52 of protector module 50, and extend through respective holes 56 therethrough into cavities 58 of dielectric housing 52, with ground plate 54 being electrically connected to ground stud 26 mounted in an end cap 28 which is itself easily connected to ground by a ground wire (not shown). Terminations of stub cable conductor wires to contacts of the module along the bottom face of the module are preferably sealed by potting material as shown in FIG. 5.
Sealing of the protector module from the environment is desired, and one system of sealing of lid 60 to housing 52 is disclosed in U.S. patent application Ser. No.07/862,677 filed Apr. 3, 1992 and assigned to the assignee hereof. The top surface of module 50 is environmentally sealed by appropriate sealing fit of lid 60 to module housing 52 and protecting ground plate 54 and lugs 152 at the upper ends of protectors 150 in a manner which also permits lid 60 to be opened for access, as shown in FIGS. 2 and 3. Such a sealing fit is obtained as a result of the particular cooperating structures of the periphery 182 of lid 60 and wall section 62 of housing 52, with lid 60 comprised of resilient elastic material such as a copolyether elastomer as is sold by General Electric Company under the designation LOMOD FR5030A or optionally of a resilient plastic material, with housing 52 preferably composed of a relatively rigid plastic material such as a blend of acrylobutyl styrene and polyvinylchloride polymers.
Wall section 62 of housing 52 preferably is canted to extend slightly outwardly at an angle of between about 2° to about 15° such as about 10° to rounded edge surface 184. Periphery 182 of lid 60 preferably defines a lip having an edge-receiving channel 186 thereinto canted upwardly and outwardly at a similar angle of between about 2° to about 15° such as about 10° and thus is complementary to wall section 62 of housing 52, with the width of channel 186 being dimensioned to form a tight fit with wall section 62 when mated therewith. Channel 186 is defined between an angled inner wall 188 and an angled outer wall 190 parallel thereto, and preferably a leadin 192 at the channel entrance is provided assisting angled wall section 62 of housing 52 to enter canted channel 186 the center of which is otherwise offset slightly inwardly from the center of edge surface 184 of canted wall section 62, since the bottom 194 of channel 186 is vertically aligned with respect thereto substantially entirely peripherally around housing 52 thus being offset outwardly from the channel entrance. With lid 60 being made of resilient material, angled outer wall 190 is elastically deflectable outwardly as edge surface 184 enters canted channel 186, with deflection initiated by bearing engagement of rounded edge surface 184 with leadin 192, as lid 60 is closed onto housing 52 with moderate pressure easily manually applied. Also outer wall 190 may be angled toward inner wall 188 at the entrance to define a constriction narrower than the thickness of canted wall section 62 assuring tight engagement without inhibiting receipt of the upper edge into the channel.
Referring to FIGS. 2 to 6, lid 60 includes a pair of hinge tabs 196 extending downwardly therefrom along rear surface 198 of housing 52 of protector module 50 and are inserted into corresponding vertical slots 200 formed through horizontal ledge sections 202 along rear surface 198. Hinge tabs 196 each preferably include a free end 204 extend around a right angle bend 206 with outwardly extending latching projections 208 defining latch surfaces 210 which are latchingly engageable with downwardly facing surfaces 212 of ledge sections 202 of housing 52. Hinge tab 196 is insertable into slot 200 from above, with angled outwardly facing surfaces 214 bearing against inside surfaces of ledge sections 202 at ends of slot 200, initiating elastic deformation of free ends 204 by reason of the resilient material from which lid 60 is made. After latch projections 208 pass below downwardly facing surfaces 212, free end 204 resumes its normal undeformed state and latch surfaces 210 opposed from downwardly facing surfaces 212 as shown in FIG. 6. Thereafter lid 60 remains attached to housing 52 even when opened.
Body sections 216 of hinge tabs 196 are of a length such that free ends 204 and bends 206 are disposed spaced from beneath slots 200 when lid 60 is closed onto housing 52. Bends 206 permit lid 60 to be rotated backwardly when fully opened as free ends 204 enter into slots 200 from below thereof but prevent hinge tabs 196 from being pulled completely upwardly through slots 200. The bends 206 preferably are at least a right angle and may be up to 180° to retain lid 60 in its rotated-back opened position clear of housing 52 allowing easy access to protectors therein, as illustrated in FIGS. 1 and 2.
The protector module of the present embodiment is adapted to be used with protector elements of any of several existing commercial designs which are in accordance with Bellcore specifications. The module is sealable against moisture, is programmable electrically in several manners, is easily used with a terminal block also modular to define a terminal block for protected circuits, and enables easy access to the protectors for service and repair. Variations and modifications may occur which are within the spirit of the invention and the scope of the claims. | A protector module (50) includes a housing (52) having cavities (58) into which are inserted electrical components such as surge protector elements (150). A lid (60) is securable to housing (52) by hinge tabs (196) having free ends (204) which are insertable through slots (200) in embossments along side surface (198) of housing (52). Latch surfaces (210) of free ends (204) latch beneath corresponding latch surfaces (212) of end walls of slots (200). Free ends (204) extend outwardly at right angles at bends (206) so that lid (60) can remain attached to the housing and retain a vertical orientation unassisted when opened permitting access to the inside of the housing (52). | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to preventing water damage. More specifically, the present invention is directed to a method and apparatus for preventing water damage to non-washable articles in a washing machine.
[0003] 2. Related Art
[0004] Many people have inadvertently damaged or destroyed valuable electronics or expensive clothing by unintentionally washing these items in a domestic clothes washer. Personal Digital Assistants (PDAs) and digital cameras do not respond well to soap, water, and agitation. Nor do various materials such as leather, fur, or certain textiles, which must only be dry-cleaned. To avoid such damage, the owner must carefully examine the washing instruction tags attached to non-washable items, and search all pockets for electronics and other non-washable items. This process is error prone, and a single mistake can prove very expensive.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a method and apparatus for preventing water damage to non-washable articles in a washing machine. A non-washable article is provided with a radio frequency identification (RFID) tag. The RFID tag is configured to emit a predetermined code, indicating that the article to which the RFID tag is associated with (e.g., attached to) is “non-washable,” when scanned by an RFID reader associated with the washing machine. The RFID reader detects the presence of the non-washable article via the predetermined code (e.g., prior to a wash cycle) and alerts the user. The user can then remove the non-washable article from the washing machine.
[0006] A first aspect of the invention is directed to a washing system, comprising: an article; a radio frequency identification (RFID) tag associated with the article and identifying the article as being non-washable; a washing machine; and an RFID reader associated with the washing machine for detecting the RFID tag.
[0007] A second aspect of the present invention is directed to a method, comprising: providing an article with a radio frequency identification (RFID) tag identifying the article as being non-washable; preventing the article from being washed in a washing machine by: scanning the washing machine using an RFID reader; and generating an alarm upon detection of a predetermined code emitted by the RFID tag.
[0008] A third aspect of the present invention is directed to a method for preventing washing of a non-washable article, comprising: providing the non-washable article with a radio frequency identification (RFID) tag; scanning a washing machine using an RFID reader to detect the RFID tag; and generating an alarm upon detection of the RFID tag.
[0009] The illustrative aspects of the present invention are designed to solve the problems herein described and other problems not discussed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which:
[0011] FIG. 1 depicts an illustrative system in accordance with an embodiment of the present invention.
[0012] FIG. 2 depicts an illustrative system in accordance with another embodiment of the present invention.
[0013] The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements.
DETAILED DESCRIPTION OF THE INVENTION
[0014] As described above, the present invention is directed to a method and apparatus for preventing water damage to non-washable articles in a washing machine. Each non-washable article is provided with a radio frequency identification (RFID) tag. The RFID tag is configured to emit a predetermined code, indicating that the article to which the RFID tag is associated with (e.g., attached to) is “non-washable,” when scanned by an RFID reader associated with the washing machine. The RFID reader detects the presence of the non-washable article via the predetermined code (e.g., prior to a wash cycle) and alerts the user. The user can then remove the non-washable article from the washing machine.
[0015] As depicted in FIG. 1 , in accordance with an embodiment of the present invention, an RFID tag 10 is attached to, or otherwise associated with, a non-washable article 12 , which in this example comprises a personal digital assistant (PDA). It should be noted, however, that the non-washable article 12 can comprise any type of article that should not be placed in a washing machine. This can include, for example, articles that would be damaged or ruined if washed (e.g., electronic devices, dry clean only clothes), articles that can damage or ruin other articles that are being washed (e.g., a pen, a darkly dyed article of clothing), and/or the like. The RFID tag 10 can be attached to, and/or installed in, the non-washable article 12 in any suitable manner/location. For example, a manufacturer 14 or user 16 of the non-washable article 12 can attach the RFID tag 10 to the exterior or interior of the non-washable article 12 . One suitable location could be the inside of the cover to the battery compartment of the non-washable article 12 , assuming the non-washable item 12 is battery powered.
[0016] The RFID tag 10 is configured to operate in a conventional manner by emitting a predetermined code 18 , in this case indicative of a non-washable status, when scanned 20 by an RFID reader 22 . The RFID reader 22 can be built into a washing machine 24 , can be attached/retrofitted to the washing machine 24 , and/or can be provided as a separate unit disposed in the vicinity of the washing machine 24 . In the case of multiple non-washable articles 12 , each non-washable article 12 can emit the same or a different predetermined code 18 indicative of a non-washable status. If different predetermined codes 18 are used for each non-washable article 12 , the RFID reader 22 can be configured to recognize each different predetermined code 18 .
[0017] The RFID 22 reader recognizes the predetermined code 18 indicative of the non-washable status of the non-washable article 12 . In an embodiment, the RFID reader 22 can be configured to scan the contents of the washing machine 24 (e.g., in the drum of the washing machine 24 ) at the onset of a washing cycle. If, in response to the scan, the RFID reader 22 receives the predetermined code 18 , indicating that the non-washable article 12 is in the washing machine 24 , the RFID reader 22 warns the user 16 by initiating an alarm 26 via an alarm system 28 . Any suitable alarm 26 , such as a visual alarm (e.g., flashing red light), an audible alarm (e.g., a loud beeping sound, klaxon), and/or the like can be employed. In another embodiment, the RFID reader 22 can provide a “shut-down” signal to the washing machine 24 , which prevents the washing cycle from commencing/continuing until the non-washable article 12 is removed from the washing machine 24 . In response to the alarm 26 , the user 16 can remove the non-washable article 12 from the washing machine 24 and restart the washing cycle. The alarm 26 can be deactivated by the user 16 and/or can be automatically terminated by the RFID reader 22 after the non-washable article 12 has been removed from the washing machine 24 and is no longer detected by the RFID reader 22 .
[0018] In another embodiment, the RFID reader 22 can be configured to periodically/continuously scan the contents (e.g., a load of laundry) of the washing machine 24 and/or the immediate vicinity of the washing machine 24 (e.g., the contents of a laundry basket near the washing machine 24 , a pile of laundry placed on the top of the washing machine 24 or nearby dryer, etc.). If, in response to the scan(s), the RFID reader 22 receives the predetermined code 18 , indicating that the non-washable article 12 is in/near the washing machine 24 , the RFID reader 22 warns the user 16 by initiating an alarm 26 via an alarm system 28 . In this way, the RFID reader 22 preemptively warns the user 16 that the non-washable article 12 is in a “washing” location.
[0019] In another embodiment, RFID tags are attached to batteries for use in consumer electronics (e.g., digital audio players, PDAs, cellular telephones, etc.). As depicted in FIG. 2 , for example, the user 16 can install batteries 30 that include RFID tags 32 in a battery-powered, non-washable article 34 . The RFID tag 32 can, for example, be affixed to an outside surface of a battery 30 . This saves the user 16 from having to modify the non-washable article 34 itself (e.g., by installing an RFID tag internally) or disfiguring the non-washable article 34 (e.g., by affixing an RFID tag externally). Similarly, a memory card 36 for storing data associated with (e.g., used by, generated by, etc.) the non-washable article 34 can include an RFID tag 38 . This protects not only the non-washable article 34 , but also the memory card 36 itself. The RFID tag 38 can, for example, be affixed to an outside surface of a memory card 36 or can be incorporated within the housing of the memory card 36 . In both of these embodiments, the RFID tags 32 , 38 operate similarly to the RFID tag 10 detailed above. To this extent, the RFID tags 32 , 38 are configured to emit a predetermined code 18 , indicative of a non-washable status, when scanned 20 by an RFID reader 22 associated with a washing machine 24 . If, in response to the scan, the RFID reader 22 receives the predetermined code 18 , indicating that the non-washable article 34 is in/near the washing machine 24 , the RFID reader 22 warns the user 16 by initiating an alarm 26 via the alarm system 28 .
[0020] The present invention can also be applied to articles which can damage other articles if washed together in a washing machine. For example, the article can comprise a pen, which if washed, could lead to the staining of the other articles in the washing machine. To this extent, an RFID tag can be attached to the pen or other potentially damaging article. Thus, the phrase “non-washable” encompasses not only articles that can be damaged when washed, but also articles that, if washed, could damage other articles being washed.
[0021] The foregoing description of the embodiments of this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible. | The present invention is directed to a method and apparatus for preventing water damage to non-washable articles in a washing machine. A method in accordance with an embodiment of the present invention includes: providing an article with a radio frequency identification (RFID) tag identifying the article as being non-washable; preventing the article from being washed in a washing machine by: scanning the washing machine using an RFID reader; and generating an alarm upon detection of a predetermined code emitted by the RFID tag. | 3 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general, to substrate coating techniques and, in particular, to a method of producing wear-resistant hard layers of hard metal compounds.
It is known to deposit such layers on substrates by vacuum evaporation or cathode sputtering in a reactive atmosphere while at the same time exciting the reaction gas by an electric gas discharge, to stimulate its reactivity. Such a discharge is present in a cathode sputtering process, and with other evaporation methods, it may be produced by means of suitable electrodes in the evaporation chamber. So called "low voltage arc discharge has proven to be particularly satisfactory for vapor deposition, if too strong a heating of the substrates is to be prevented. That is, due to the particularly strong activation of the reactants in the low voltage arc, and adequate reaction is obtained even on cooled substrates, which frequently is not the case with other methods of ion supported reactive deposition.
In particular, the evaporation of titanium in nitrogen, which results in hard, wear-resistant TiN coatings, is known, Due to the brilliance and golden appearance of such castings, they are used, among others, for pieces of jewelry and utility articles. It is further known to produce wear-resistant coatings by evaporating titanium in acetylene or ethylene while evaporating the titanium by means of an electron beam and using additional electric fields for activating the residual gas atmosphere in the evaporation space. This method, however, has a disadvantage in the relatively high temperature (almost 1000° C.) to which the substrates to be coated, are heated. Many materials do not stand such a temperature so that in such cases the mentioned method cannot be applied.
A similar method relates to cathode sputtering of titanium in hydrocarbons with admixed nitrogen, producing a condensate of a crystalline solid solution of titanium carbide and titanium nitride. Such layers are also hard and abrasion-resistant, however, because of their carbide content they are susceptible to oxidation, particularly if during later use they are exposed to high temperatures as in the case of carbide-tipped tools, for example.
SUMMARY OF THE INVENTION
The present invention is directed to a method of producing wear-resistant hard layers, particularly on the basis of hard metal compounds of titanium, zirconium and hafnium, which is reliable and economical and furnishes layers with a substantially reduced susceptibility to oxidation.
The inventive method of depositing hard, wear-resistant coating by precipitating them in a nitrogen containing residual gas atmosphere while simultaneously activating the residual gas by an electric gas discharge, is characterized in that the deposition is effected in a residual gas atmosphere containing nitrogen, oxygen and carbon, with the atomic number proportion of oxygen to carbon ranging between about 0.5 and 1.5. Preferably, carbon monoxide is used as the residual gas component furnishing carbon, and the deposition is effected in an electric low voltage arc discharge, while applying to the substrates to be coated, or to their support, a negative voltage of about 200 volts relative to the wall of the evaporation chamber. Frequently, however, even substantially differing voltages may be used and are expedient. To be able to maintain the low voltage arc also at a relatively low concentration of reactive gases in the evaporation chamber, argon or another neutral or inert gas having a partial pressure ranging between about 5×10 -4 and 3×10 -3 may be added to the residual gas atmosphere.
With the inventive method, layers are produced which are composed of mixed crystals of hard metal compounds, such as titanium carbide, titanium nitride, and titanium oxide, for example, and during the reactive process of deposition, it is only in the course of the deposition proper that the respective hard metal compounds are formed, due to the reaction of the evaporated metal with the residual gas atmosphere. As mentioned, it has been known to produce each of the indicated hard metal compounds individually, through a reactive deposition in a vacuum, thus for example titanium nitride by evaporating metallic titanium in a nitrogen atmosphere, titanium carbide by evaporation in a hydrocarbon atmosphere, and titanium oxide in an oxygen atmosphere. To this end, the presence of the reactive component of the residual gas must be adjusted very accurately and maintained constant if uniform layers are to be obtained, since relatively small upward deviations from the desired value already result in the formation of overly soft layers, due to gas inclusions in the layer. Too low a partial pressure of the reactive component causes a deviation from the desired chemical composition. Except for the mentioned cathode sputtering of titanium in a nitrogen-hydrocarbon mixture, no practical method has been known as of yet, for reactively depositing mixtures (crystalline solid solutions).
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For an understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawing and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE FIGURE
The only FIGURE of the drawing is a sectional view of an apparatus used in practicing the inventive method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, the invention is explained in more detail while considering some examples of its application. The accompanying drawing illustrates an evaporator suitable for carrying out the invention. The FIGURE shows a vacuum chamber 1 having a connection 8 for evacuation and communicating, through an aperture 18 in a wall portion 9, with a hot cathode chamber 13. A hot cathode 19 is accommodated in chamber 13, which is supplied with current from a source (not shown). A crucible 6 for the evaporative metal is placed on the bottom 7 of the evaporation chamber. The crucible may be cooled if necessary. The evaporative chamber accommodates a cylindrical structure 2 for supporting the substrates 3 to be coated. Hot cathode chamber 13 is connected to a gas supply line and the supply of gas is controllable by a valve 12. To produce a magnetic field substantially parallel to the axis of the evaporation chamber, a field coil 15 is provided. The substrates to be coated are secured to that side of supporting structure 2 which faces the evaporative source 6.
To produce coatings in accordance with the invention, lumps of metallic titanium were placed in crucible 6, the chamber was evacuated to 10 -5 millibar and a gas mixture containing argon, nitrogen and carbon monoxide was introduced through valve 12 into chamber 1 and continually evacuated therefrom in a amount to maintain a pressure of 5×10 -2 millibar in the cathode chamber and a total pressure of about 10 -3 millibar in the evaporation chamber. In order to protect the hot cathode, it is also possible to separately introduce argon into the hot cathode chamber, and the reactive gases through a valve 16 into the evaporation chamber, so that during the evaporation, the evaporation chamber is filled predominantly with the required reactive residual gas atmosphere mixed with argon, whose pressure can be adjusted to an optimum by continuous pumping down. The hot cathode, which was put at ground potential, was heated with 1.5 killowatt and then a voltage of +70 volt was applied to the anode and a voltage of -50 volt, as bias voltage, was applied to the substrates. The anode is formed by the crucible 6 and charged through support 5 by appropriate supply means not shown. By briefly applying the anode voltage to the wall 9 separating hot cathode chamber 13 from evaporation chamber 1, a low voltage arc was struck. The above voltage indications as well as the following ones all refer to differential voltages relative to the chamber wall to which the ground potential is applied. This resulted in a current of 85 A flowing through the hot cathode 19. The current flowing through the anode 6, 5 was 100 A. The difference between the two currents equals the current flowing through the substrates 3. By the current flowing through the anode, i.e. crucible 6, the titanium received therein was melted and evaporated at a rate of about 0.4 grams per minute. Due to the effect of the residual gas, strongly ionized by the low voltage discharge between the hot cathode and the anode, a hard, extremely firmly adhering layer of yellowish color was obtained on the substrates 3 secured to support 2.
In various examples of the application of the method, in each instance with a titanium evaporation rate adjusted to obtain, on a test glass, a deposit of 0.33 micrometers in thickness per minute and with a substrate voltage of -50 volts, coatings in various color hues were obtained which all exhibited an extremely high resistance to abrasion.
Example 1: with P N .sbsb.2 =2×10 -4 mbar/P CO =1×10 -4 mbar
Example 2: with P N .sbsb.2 =2×10 -4 mbar/P CO =2×10 -4 mbar
Example 3: with P N .sbsb.2 =2.5×10 -4 mbar/P CO =3×10 -4 mbar
Example 4: with P N .sbsb.2 =3×10 -4 mbar/P CO =4×10 -4 mbar
Example 5: with P N .sbsb.2 =3.5×10 -4 mbar/P CO =4.5×10 -4 mbar
Where P N .sbsb.2 is the partial pressure of nitrogen in the residual gas atmosphere, and P CO is the partial pressure of carbon monoxide.
Coatings of this kind have proven suitable particularly for tools and utility articles. For example, they more than doubled the life of drill bits.
While carrying out the inventive method with residual gas components containing oxygen and carbon, particularly such components or gas mixtures, aside from the carbon monoxide mentioned in the examples, in which the oxygen to carbon ratio expressed in atomic number proportions, is one to one or less, for example (CH 4 +H 2 O) or (C 2 H 2 +O 2 ) and corresponding hydrocarbons adequately mixed with O 2 or with compounds containing oxygen, is advisable.
It will be understood that the above indications are not values to be absolutely observed, but values which brought optimum results with the evaporator used in the examples. Depending on the apparatus, the optimum values may vary by up to plus or minus 25%. It may further be advantageous first to apply a higher potential difference between the anode and the substrates, to increase the energy of the particles impinging on the substrate surface and thereby to improve their anchoring and firm adhesion, and then gradually reduce the potential difference during the deposition of further particle layers of the coating.
While producing coatings in accordance with the invention, it was possible throughout to keep temperatures on the substrates below 200° C. frequently even at a substantially lower level. High-gloss coatings were obtained, provided that the surfaces to be coated had been polished in advance. No finishing was necessary. The hardness of all the coatings exceeded 2000 kilograms per millimeters square according to the Vickers hardness test.
Since the reactive residual gas components continue to be consumed in the evaporation process, the reactive gas must continuously or intermittently be resupplied, in order to keep the required partial pressures constant. The hot cathode chamber also must continually be supplied with gas (preferably argon) in an amount sufficient to make the cathode drop distance, depending on the mean free path of the gas molecules, equal in order of magnitude to the distance between hot cathode 19 and separating wall 9. It is advisable to electrically insulate the separating wall 9, for example with insulators 10, in which the aperture connecting the hot cathode chamber with the evaporation chamber is provided, and keep it at a floating potential during the inventive process. Support 5 is also insulated from chamber wall 7 with insulator 4. A positive potential or the ground potential may be applied to the evaporation crucible, and the ground potential or a negative potential is then applied to the cathode. An operation with both the cathode and the evaporative material at a positive potential relative to the ground is also possible. The substrates to be coated are always kept at a negative potential relative to the anode, and they may temporarily (in particular intermittently) even be connected as the cathode of an independent gas discharge.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A method of depositing hard, wear-resistant coatings on workpieces and utility articles by evaporating a metal such as titanium in a reactive atmosphere. To make the coating hard as far as possible, wear resistant, and less susceptible to oxidation, the deposition is effected in an atmosphere containing nitrogen, oxygen and carbon, with the atomic number proportion of O to C ranging between 0.5 and 1.5. An evaporation by means of a low voltage arc discharge and the use of CO as the residual gas atmosphere are particularly advisable. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation of application Ser. No. 14/629,093, filed Feb. 23, 2015, which is a continuation of Ser. No. 13/547,573, filed Jul. 12, 2012, now U.S. Pat. No. 8,960,949, which is a continuation of application Ser. No. 12/510,090, filed Jul. 27, 2009, now U.S. Pat. No. 8,240,874, which is a continuation of application Ser. No. 11/520,051, filed Sep. 11, 2006, now U.S. Pat. No. 7,566,149, which is a continuation of application Ser. No. 10/460,047, filed Jun. 12, 2003, now U.S. Pat. No. 7,125,140 B2, which is a continuation of application Ser. No. 09/583,349, filed May 31, 2000, now U.S. Pat. No. 6,585,391 B1, the entire contents of which are expressly incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
FIELD OF THE INVENTION
The present invention relates generally to portable illumination devices, and more particularly, but not entirely, to flashlights with enhanced functionality and reliability.
BACKGROUND OF THE INVENTION
Flashlights and other portable illumination devices are very useful devices that include an illumination source as part of an electrical circuit incorporating one or more batteries (to supply current to the illumination source) and a switch to complete or interrupt the circuit. Typically, manually operated mechanical switches which have been designed for the mechanical sturdiness have been used as flashlight switches, such as the switch disclosed in U.S. Pat. No. 4,286,311 (granted Aug. 25, 1981 to Maglica), which is hereby incorporated in its entirety by reference. The function of a switch in previously available flashlights has been limited to completing or interrupting the electrical circuit to the illumination source.
The switch used in the '311 patent is a push-button switch featuring a rotary contact, which is rotated axially when the button is depressed, “wiping” across stationary contacts that complete the circuit with the lamp and the batteries, in order to clean those surfaces. This is done to overcome the problems of oxidation and buildup of dirt on the electrical contacts, occurrences which increase electrical resistance in the circuit and thus undesirably limit the current flow to the illumination source.
As a result, the previously available switches require that the switch be activated with enough force to clean the contacts and rotate, or otherwise move cleaning components. The previously available flashlights using such switches thus require an amount of force large enough to provide the “wiping” effect. A MAGLITE® flashlight, believed to be a market embodiment of the device represented in the '311 patent, requires a mass of over 1270 grams to latch the '311 type-switch closed when the weight was applied to the pushbutton on the flashlight until the switch was triggered. Moreover, the '311 type-switch had a stroke distance of over 5 mm to the latching position. This large force and long stroke distance may be difficult for a person with small hands to use while grasping the flashlight, or a person with reduced hand strength, as from an arthritic hand condition.
It is commonly accepted in the industry as true that the large amount of force and distance required to operate the switch, and the audible “click” that accompanies its function, may also serve as a way to prevent the switch from being accidentally operated, as inside a backpack, or toolbox.
Additionally, a switch structure like that shown in the '311 patent provides simply a way for the circuit of the flashlight to open and close, it does not provide a structure by which additional electrically based functions can be easily added to the flashlight.
It is noteworthy that none of the known prior art provides a portable illumination device with a switch that requires very little force to operate, or a short stroke distance to operate, or a switch which combines the features of needing little force to operate or needing a short stroke distance to operate, with the ability to integrate additional electronic functions within the switch structure.
The available art is thus characterized by several disadvantages that are addressed by the present invention. The present invention minimizes, and in some aspects eliminates, the above-mentioned shortcomings and other problems, by utilizing the methods and structural features described herein.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a portable illumination device that is easy to use.
It is another object of the present invention to provide a portable illumination device that requires a small amount of pressure to operate a switch mechanism which turns the device on and off.
It is a further object of the present invention to provide a portable illumination device with a switch which requires little movement of a user's finger, and requires less movement than the previously available devices, to operate the device between an operational state and an inactive state.
It is an additional object of the present invention to provide a portable illumination source that is capable of multiple functions, which are controlled by a single switch.
It is a further object of the present invention, in accordance with one aspect thereof, to provide a flashlight which can include multiple functions actuated by a single switch.
It is another object of the present invention to provide a portable illumination device with increased reliability.
It is an additional object of the invention, in accordance with one aspect thereof, to provide a metal flashlight which has an electrically resistive coating provided on the flashlight for improved appearance or protection with the flashlight also including structures to improve electrical conductivity through the flashlight.
The above-recited objects, and other objects not specifically recited, are realized in a specific illustrative embodiment of a flashlight and flashlight electrical connectors as described herein. The flashlight described herein includes a subminiature pushbutton switch that requires a small amount of pressure and a short stroke distance to operate between an open mode (electrically non-conductive) and a closed mode (electrically conductive).
The switch is preferably attached to a member on which an electrical connective structure is disposed. This preferred structure can be carried out by attaching the switch to a printed circuit board. Electrically conductive springs are also preferably attached to the member, so as to make electrically conductive contact with the electrically connective structure.
The member and the switch are preferably protected by a housing, such that the compressive force of the springs (preferably a first spring and second spring) is absorbed and resisted by the housing. In one preferred embodiment of the invention, one spring makes electrically conductive contact with an illumination source, such as an incandescent lamp, or the electrically conductive structures leading to the lamp. The second spring makes electrically conductive contact with a battery, or a electrically conductive structure leading to a battery. A conductive strip is preferably provided to complete the electrical circuit.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the invention without undue experimentation. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become apparent from a consideration of the subsequent detailed description presented in connection with the accompanying drawings in which:
FIG. 1 is a side, partially cut away view of a flashlight made in accordance with the principles of the present invention;
FIG. 2 is a perspective view of the switch structure portion of the Flashlight FIG. 1 ;
FIG. 3 is a perspective view of the switch housing structure portion of the flashlight of FIG. 1 ;
FIG. 4 is a side, partially broken away view of a flashlight made in accordance with the principles of the present invention; and
FIG. 5 is an exploded view of the embodiment shown in FIGS. 1 through 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the purposes of promoting an understanding of the principles in accordance with the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention claimed.
Referring now to FIG. 1 , FIG. 1 shows a flashlight made in accordance with the principles of the present invention. This specific illustrative embodiment will be used to explain the principles of the present invention, but it will be understood that the scope of the present invention extends beyond flashlights of the FIG. 1 design to other flashlight and portable illumination designs that may be made under the principles of the present invention. The FIG. 1 embodiment is a flashlight, with a tubular flashlight body 10 (cylindrical knurling is shown on the tubular flashlight body 10 ), and a flashlight head 11 that holds an illumination source 31 . The head 11 preferably includes structures which adjust or focus the light beam emitted by the flashlight, or includes structures which provide an adjustable beam. It is also within the scope of the present invention to provide the head 11 with a plurality of lenses, structures for changing the color of the light beam emitted therefrom, or any other similar and desirable feature known, or readily ascertainable to those skilled in the art.
As shown in the embodiment of FIG. 1 , the present invention includes a unique switch structure for use in a portable illumination device. In this embodiment, the switch structure features a switch 20 attached to a member 24 . The details of the switch structure are shown in FIG. 2 . Preferably, the switch 20 is manually actuated by the hand of the user of the portable illumination device. The switch 20 is most preferably a subminiature pushbutton type of switch, although it is understood that other types of switches may be used. Examples of the preferred switch types which can be used to carry out the functions of the switch 20 include miniature pushbutton switches, subminiature pushbutton switches, micro switches and toggle switches.
While other types of switches may be used, the preferred switch is a double push-double pole switch which increases the reliability of the switch structure, by providing dual connections for each position in which the switch may be operably actuated. This increases the reliability of the switch over that found in the prior art, by providing dual paths along which current can travel to complete the circuit of the portable illumination device. Should oxidation, or dirt cause one pathway to become less conductive, contact may still be made across the second pathway provided by the preferred switch.
In preferred embodiments of the present invention, the switch 20 requires a small amount of force to actuate. This force is defined herein in units of gram force (gf). A gram force is equivalent to the force exerted by gravity on a mass of one gram at the earth's surface. The force used to actuate the switch 20 as used in this detailed description, and the claims consists of the force used to actuate the switch 20 in the absence of the flexible outer cap (shown in FIG. 1 at 28 ). In one embodiment of the present invention, the switch 20 requires less than about 1000 gf to be operably actuated. In the preferred embodiments, the switch 20 requires from about 50 gf to about 500 gf to operate, in the more preferred embodiments, the switch 20 requires from about 75 gf to about 300 gf to operate, in the most preferred it requires from about 100 gf to about 275 gf to operate.
As discussed above, the force required to actuate the switch 20 preferably used in the embodiments of the present invention is greatly reduced when compared to the force required to operate the switches presently used in portable illumination devices. This allows a device made in accordance with the principles of the present invention to be used by users who have reduced hand strength, as from an arthritic condition, and provides a significant advantage over the prior art.
Another feature of the preferred switch 20 is the reduction of the stroke distance that the switch requires to operate. A preferred pushbutton type of switch has two positions, a momentary position and a latching position. When the plunger 22 of the switch is fully depressed from the open position to the momentary position, this is referred to as the full stroke, and when the plunger is depressed from the latching position to the momentary position, this is referred to as the locking stroke. In a preferred embodiment, the full stroke of the switch 20 requires the plunger 22 to move less than about 4.0 mm. In the more preferred embodiments, the full stroke is between about 0.5 mm to about 3.75 mm, and in the most preferred it is from about 1.0 mm to about 2.75 mm. The locking stroke distance of the preferred embodiment is less than about 2.0 mm. As discussed above, these stroke distances represent a decrease over those currently used in the prior art devices, and allow a user with reduced hand strength, or a small hand size to operate a portable illumination device made in accordance with the present invention. One preferred switch 20 which may advantageously be used in the embodiments of the present invention is available from E-Switch of Brooklyn Park, Minn. serial no. TL 2201 (DPDT) EE.
The switch 20 , is attached to a member 24 . In this embodiment, the member 24 is planar, but it may be constructed with any alternative shape that may be used to carry out its function. The member 24 preferably has associated with it structures which carry out the function of a means for making an electrical connection, such structures being represented by electrically conductive paths 40 , as will be explained more fully below. The preferred structure for the member 24 is a printed circuit board, as can be readily fabricated by those skilled in the art, with the electrically conductive paths 40 , preferably carried out as circuit traces formed on the printed circuit board, and carrying out the function of the means for making an electrical connection.
The embodiment of the present invention may desirably include a functional circuit, or a plurality of functional circuits, represented in FIG. 2 as at box 42 with the functional circuits which may be included in the box 42 being represented at 44 in FIG. 2 . It will be understood that no functional circuit, a single functional circuit, or a plurality of functional circuits can be included in a single embodiment of the present invention and all are intended to be included within the scope of the present invention. The functional circuits 42 and 44 serve as one example of a means for providing an additional electrical function to the flashlight. It will be appreciated that many different structures can be arrived at by those skilled in the art using the information provided herein to fabricate the functional circuits within the scope of the present invention.
Possible additional electrical functions that may be added to a portable illumination device made in accordance with the present invention include a strobe light function, a signal flashing function, an electronic game, an automatic shutoff function, audio functions, interactive Morse code, a global positioning transponder, a laser pointer, a motion detector, a sound to light transmitter/receiver, an infrared light, a digital compass function, or any other additional electrical function. It will be appreciated that the present invention encompasses within its scope the inclusion of additional structures necessary to add such functions.
It will be further appreciated that in an embodiment utilizing a double push-double pole switch, multiple functions can be controlled using the same switch. It may be preferable to design the circuitry of the additional functions such that multiple pushes on the switch control different features. For example, a single push may activate the flashlight beam, while two pushes activates an additional function such as a strobe feature and three pushes activates another additional function, such as a motion sensor. This technique could be used to control a large number of functions, the momentary and the latching positions of a pushbutton switch could be utilized in such control. Use of a switch with additional push features would allow for the control of even a larger number of functions. Alternatively, toggle switches, other types of switches, or multiple switches may be used to control the additional functions.
A strobe light feature incorporated into the embodiments of the invention preferably provides the feature of setting the illumination source to flash at a predetermined rate, or rates. Alternatively, the strobe light feature could have an adjustable rate. This feature would allow a portable illumination device with this feature to be used as an illumination source, and as a strobe light for checking moving or rotating, equipment at remote locations.
A signal flashing feature is preferably included to have the portable illumination device flash a signal pattern, such as an SOS signal in Morse code, or another such signal, to be used as a safety or communications device. An electronic game is optionally incorporated into the device as an amusement feature, for entertaining a user, such as a child on a camping trip.
An automatic shutoff feature preferably comprises a timer that automatically shuts off the flashlight after a predetermined period. This feature would eliminate the need for an audible “click” and a large amount of force to warn the user that the device has been actuated. This function could prevent the battery from being drained, should the device be accidentally actuated, as in a backpack or toolbox, even if the user is not aware that the device has been actuated. This ability to perform the same end result without requiring additional user action represents a desirable improvement over the prior art.
An interactive Morse code feature, or a sound to light transmitter/receiver, is preferably included to allow the portable illumination device to function as a communication device. Additional structures such as speakers, lenses, or photoelectric eyes can be included to realize these functions and portable illumination devices with such structures are also included within the scope of this invention.
A global positioning (GPS) transponder, or a digital compass, is also optionally included as an additional electrical function. Such features would allow the flashlight to be used for surveying, orienteering, camping, backpacking or hiking while reducing the amount of equipment that needs to be carried. Additional structures and means such as light emitting diodes, or liquid crystal displays can be installed in the surface of a portable illumination device with such features to allow the use of such features, and inclusion of such devices are encompassed within the scope of the present invention.
A motion detector is preferably included in the embodiments of the present invention which allow a portable illumination device to be used as a motion sensitive illumination device, or as a makeshift burglar alarm in a remote location, such as while camping. An infrared light or a laser pointer could also be included and controlled as an additional feature, allowing the portable illumination device to be used as a pointer, marker, or heater. The installation of additional structures necessary to accomplish these functions is also included within the scope of the present invention.
Audio features, such as beeping to indicate that a function has been activated can also preferably be incorporated into embodiments of the present invention. Inclusion of an audio transducer, namely a speaker, to provide for audio features is also included within the scope of the present invention.
As shown in FIGS. 1 and 2 , one embodiment of the present invention includes the feature of one or more conductive springs attached to the member 24 and making electrically conductive contact with the electrically conductive paths 40 . The electrically conductive paths 40 are preferred examples of structures which can be used to function as means for making an electrical connection and any structure which carries out similar or equivalent functions is intended to fall within the scope of the means for making an electrical connection. For example, while printed circuit board traces are presently preferred, any structure which performs the function of carrying electrical current is intended to come within the scope of the means for making an electrical connection.
In the pictured embodiment, there are two springs 16 and 18 , which are attached at opposite ends of the member 24 , and make electrically conductive contact with the electrically conductive paths 40 . The springs 16 and 18 may be attached by any suitable technique, including soldering, or any other technique known to those skilled in the art.
As shown in FIG. 1 , spring 16 makes electrically conductive contact with a battery 12 , the terminal of the battery 12 being indicated at 17 in FIG. 1 . It will be appreciated that the present invention may be constructed in various embodiments that use a single battery, or plurality of batteries, which may be of any suitable size and shape for the portable illumination device. When reference is made to a battery in this specification, the term includes multiple batteries as well as single batteries, and includes all battery types, rechargeable and single use. The term battery includes all structures capable of storing and providing electrical charge and current sufficient to operate a portable illumination device. It is preferred, however, that the batteries be of the primary cell sizes commonly referred to in the industry as D, C, AA, and AAA batteries. The conductive spring 16 , thus places the switch structure in electrically conductive contact with one terminal 17 of the battery.
The second conductive spring 18 , of the embodiment depicted in FIG. 1 places the switch structure in electrically conductive contact with the illumination source 31 . It will be appreciated that the term illumination source includes all means for producing illumination through the use of electric current, which are suitable for use in a portable illumination device. Examples of such illumination sources include incandescent lamps (including halogen lamps), fluorescent lamps, light emitting diodes, and other solid state light emitting devices, as well as any other light emitting device known or readily ascertainable to those skilled in the art.
The embodiment shown in FIG. 1 , includes structures for holding the illumination source 31 . In the illustrated embodiment, the structure for holding the illumination source 31 is represented as a supporting collar 30 . The supporting collar 30 , and its associated structures, are presently preferred examples of a means for holding the illumination source. Many different structures can carry out the functions of the means for holding the illumination source and it is preferred that the structures carrying out the function of the means for holding the illumination source be electrically conductive. It will be appreciated that all structures ascertainable to those skilled in the art which are capable of performing the function of holding the illumination source, either with, or without the additional circuit completion function are included within the scope of the means for holding the illumination source of the present invention. Moreover, any structures which carry out the functions, or equivalent functions, of holding the illumination source in the proper position and which are capable of being utilized as a portion of the circuit between the illumination source 31 and the battery 12 are also intended to come within the scope of the means for holding the illumination source of the present invention.
FIGS. 1 and 3 show a protective housing 14 . In the depicted embodiment, the protective housing 14 functions to protect the switch structure from jarring, or other forces applied to the flashlight. The protective housing 14 also serves to protect the switch structure from the compressive force of the conductive springs 16 and 18 . As shown in FIGS. 1 and 3 , the protective housing 14 encloses the switch structure. An aperture 26 , is provided for the plunger 22 to extend there through, so that the switch may be actuated. Openings 50 are provided for the conductive springs 16 and 18 to extend out from the housing 14 . A wall 52 of the housing 14 lies inside the opening 50 , there is a smaller opening 54 in the wall 52 , through which the conductive spring 16 can make conductive contact, or be attached to the member 24 . When the spring ( 16 in FIG. 2 ) is compressed, for example by the battery 12 , the spring is compressed against the wall 52 of the protective housing 14 . The protective housing 14 thus absorbs and resists the force of the spring compression, protecting the switch structure positioned inside the protective housing 14 . It will be appreciated that other configurations of a housing capable of performing the function of protecting the switch structure are readily ascertainable to those skilled in the art, and all such structures are included in the scope of the present invention.
FIG. 4 illustrates another preferred feature of the present invention. Many flashlights and other portable illumination devices are constructed from various metals. In these flashlights, it has been a common practice to utilize the conductive properties of the metal flashlight body to form a portion of the electrical circuit between the battery and the illumination source. An example of such a flashlight is disclosed in the '311 patent.
It has also been a common practice to treat the surface of metal flashlight bodies to provide a hardened protective surface and a finished appearance, including a color. This has been done in several ways, for example by anodizing an aluminum flashlight body, or by coating the metallic body with enamel or paint. Each of these methods of surface treatment has the effect of reducing the conductivity of the surface of the flashlight body. Anodizing aluminum, for example, is used to provide an insulative coating in aluminum conductors.
To overcome the problems of reducing the conductivity of the metal by surface treatment, several methods have been used. A portion of the anodized, or other coating may be removed by grinding, or may be covered by a mask prior to treatment, which is then removed to leave an untreated portion. These techniques produce a surface capable of conducting electricity, but in many cases the conducting ability of bare metal is reduced over time, as the metal, especially aluminum, is oxidized by the air forming a resistive coating on the metal. Another method which has been used is to coat sections of the metal with a conductive film, either over the protective coating, or over spots of metal left untreated by the other methods. While improving the conductivity, this alternate method also has drawbacks, as use wears the conductive film off electrical resistance increases, and the previously noted problems then occur.
The present invention provides a solution to this problem, with one possible embodiment which solves the described problem being represented in FIG. 4 . Preferably, a conductive strip is provided to complete the electrical circuit so that the metallic flashlight body is not used to complete the circuit. In the embodiment shown in FIG. 4 , a conductive strip 34 is positioned running along the inside surface of the flashlight body 10 to provide a low resistance current path. At the first end of the flashlight, the conductive strip 34 , makes contact with a conductive connector 32 that is located between the protective housing 14 and the conductive strip 34 . The conductive connector 32 is in contact with the supporting collar 30 , allowing the illumination source to be electrically connected to the conductive strip 34 . At the second end of the flashlight body 10 , the conductive strip 34 makes contact with a conductive spring 36 located in the end of the flashlight body 10 . The conductive spring 36 , makes contact with one terminal of the battery 12 . The conductive strip 34 thus completes the circuit between the illumination source 31 and the battery 12 .
It will be appreciated that portable illumination devices, including flashlights, made in accordance with the above description will accomplish some or all of the above-recited objectives of the present invention. The use of a unique switch structure results in a device with a switch that is easy to operate, may require less actuating force, can have a reduced actuating distance with increased reliability. Additional electrical functions may be included in the circuit of the device, and be controlled by the same switch structure. Additionally, the use of an internal conductive strip, allows for improved conductivity over metal flashlights with surface treatments, while still keeping the improved appearance and protection of a treated metal surface.
Reference will now be made to FIG. 5 , which is an exploded view of the embodiment shown in FIGS. 1-4 . The following table contains an exemplary list of the parts used in this embodiment of the present invention.
Reference Numeral
Structure
60
Lens Ring
62
Lens
64
Lens O-Ring
66
Reflector
68
Head O-Ring
70
Head
72
Illumination Source Holder Ring
31
Illumination Source
30
Supporting Collar
32
Conductive Connector
74
Illumination Source Insulator
18
Conductive Spring
24
Member
20
Switch
22
Switch Plunger
16
Conductive Spring
14A
Protective Housing Top
14B
Protective Housing Bottom
76
Retaining Ring
28
Protective Flexible Diaphragm
34
Conductive Strip
80
Lock Switch Spring
10
Flashlight Body
36
End Cap Conductive Spring
82
End Cap O-Ring
84
End Cap
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements. Thus, while the preferred embodiment(s) of the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made without departing from the principles and concepts set forth herein. | A multi-mode portable illumination device includes a switch structure featuring a substantially planar member and a mechanical switch which requires a relatively small amount of force and a short stroke distance to actuate. The mechanical switch is attached to a member which contains circuit(s) adding additional functionality to the multi-mode portable illumination device. The member has conductive springs attached to either end that are used to complete the electrical circuit with the battery and the lamp, while their compressive force is absorbed by a housing protecting the switch structure. A conductive strip is used to improve the conductivity of the circuit in a metal multi-mode portable illumination device which has been provided with an electrically resistive protective coating. | 5 |
This is a Continuation, of application Ser. No. 775,022 filed Mar. 7, 1977, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to apparatus for laying fiber fleeces or the like, usually supplied from a carding machine or the like, onto a withdrawal belt moving at a predetermined speed.
In high-speed apparatus for laying fiber fleeces, any sudden change in speed of the various conveyor belts in the apparatus can cause irregularities and distortions in the fleece layer. Thus, during a sudden acceleration of the conveyor belts the fleece does not follow immediately, and at high operational speeds air currents are generated which tend to raise the fleece from the belts and can lead to narrowing or stretching of the fleece at points between conveyor belts.
One of the objectives in designing apparatus for laying fiber fleeces has been to provide control means for maintaining the conveyor belts in a predetermined relationship whereby the fleece layer is maintained more uniform. In prior art apparatus each conveyor belt is frequently controlled by a separate DC motor, the DC motors enabling digital control of the speeds of the belts. This, however, requires a complex and therefore expensive control device and also requires continuous supervision by highly skilled personnel. Furthermore, the adverse affects caused by air currents are not eliminated.
Other prior art devices have been designed to decrease the high rate of acceleration. This is difficult to control, however, as the fleece is fed to the apparatus at constant speed and must be withdrawn at constant speed.
Another prior art apparatus is known in which there is a feed belt driven at a predetermined speed, a reciprocably movable main or storage car and laying car and two conveyor belts which extend partially parallel to each other between the main and layer cars. One of the conveyor belts, a main belt, passes over rollers on the main and layer cars. Three auxiliary cars are provided which are intended to effect balance of the belt speeds during laying of the fleece in a cross-over form. Also, the drive requires at these two different gears. This apparatus has the disadvantage that it is relatively expensive and complex, both in structure and with respect to the control device required to operate the apparatus.
An object of the present invention is to provide apparatus for laying fiber fleeces which has a simplified construction and reduction in the number of parts.
A further object of the invention is to provide an apparatus in which control of the synchronous running of the moving parts is simplified.
SUMMARY OF THE INVENTION
The apparatus of the present invention includes a feed belt, a main car, a layer car, a storage car, and two conveyor belts which extend in part parallel to one another between the main and layer cars. One of the conveyor belts passes as a main belt over rollers on both the main and layer cars. The storage car has rollers around which the second conveyor belt passes. A single balance car is provided for the main belt, and the storage and layer cars are connected by a common drive unit, e.g. a chain which derives its drive from the feed belt and via the driven layer car.
The main belt which runs over both the layer and balance cars passes around the end of the storage. This construction is compact as extra space is not required for belt travel. Only one storage car is required. It is possible for the speed of the layer car to be changed by means of the balance car to a speed different from the fleece speed, control being maintained by the common drive unit, i.e. by synchronization of the control chain. It will be appreciated that all parts of the apparatus are easily accessible and easily maintained.
The storage car has a jib supporting the second conveyor belt. The control chain may be passed over the end of the jib to the layer car. In this case the control chain is advantageously passed over a gear wheel non-rotarily connected to a laying roller of the layer car. This serves as one of the two drives for the control chain. The other drive for the control chain is derived directly from the driven speed belt.
From the driven belt wheel of the feed belt a drive chain leads over the roller of the main belt on the balance car. The drive for the second conveyor belt located on the storage car is derived from the driven main belt. Both belts thus run at the fleece speed or doffer speed. The layer car can be arranged to move reciprocably by means of a car traction chain and two gear wheels. The gear wheels mesh with a stationary measuring chain, the gear wheels being alternately provided in opposed directions with freewheel clutches. Thus, each individual layer roller of the layer car is respectively driven by each gear wheel. The measuring chain which is an endless chain passing over wheels is driven by movement of the car traction chain. This drive means eliminates the hydraulic lines normally required to operate the clutch located on the layer car which must be continuously reciprocated. The driving force is applied to those drive parts which are non-rotarily supported. The measuring chain is simply driven by the car traction chain, and consequently the layer car which is subjected to continual reciprocating motion is made considerably lighter, an important feature since the layer car is continuously being braked and accelerated.
The drive for the measuring chain is derived from a turning wheel of the car traction chain, the shaft of the turning wheel of the car traction chain being connected with the shaft of the turning wheel of the measuring chain at a drive ratio of 2:1. The corresponding chainwheels which are connected by a chain can be designed with a corresponding transmission ratio so that the shaft of the measuring chain revolves twice as fast as the shaft of the car traction chain, the turning wheels on both chains being the same size.
A clutch is located on the chain wheel of the measuring chain to engage and disengage its shaft. To effect a change in the direction of the power flow without change in direction of the layer car, a freewheel device is located on the shaft for the drive of the measuring chain. The freewheel device is attached to the machine frame and prevents the shaft of the measuring chain from rotating in the wrong direction. The engagement of the endless measuring chain with the layer car is preferably effected in such a way that the endless measuring chain is passed over a turning chainwheel of the layer car.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagrammatic side elevation of a first embodiment of the fleece laying machine;
FIG. 1a is a view similar to FIG. 1 on an enlarged scale;
FIG. 2 is a cross-sectional view taken aong the line II--II of FIG. 1 illustrating the position of the individual drive elements;
FIG. 3 illustrates the layer car, the balance car and the storage car, the conveyor belts having been omitted;
FIG. 4 is a diagrammatic front elevation of the fleece-laying machine showing the cars at their maximum end positions;
FIG. 5 is similar to FIG. 4 but shows the positions of the balance car and the storage car when the speed of the layer car does not coincide with the fleece speed;
FIG. 6 is a diagrammatic side elevation of a further embodiment of the fleece-laying machine;
FIG. 6a is a view similar to FIG. 6 on an enlarged scale;
FIG. 7 is a cross-sectional view taken along the line II--II of FIG. 6 illustrating the position of the individual drive elements;
FIG. 8 illustrates the layer car, the balance car and the storage car, the conveyor belts having been omitted;
FIG. 9 is a diagrammatic front elevation showing the positions of the balance car and the storage car when the speed of the layer car does not coincide with the fleece speed; and
FIG. 10 is a diagrammatic plan view of the drive means for the endless measuring chain.
DETAILED DESCRIPTION OF INVENTION
Referring to FIGS. 1-5, the fleece-laying machine 1 has a feed belt 2 with rollers 3 and driven belt roller 4. Located transversely to the feed belt 2 is a withdrawal belt 5 on roller 6. The fleece material is deposited transversely and in a zig-zag configuration relative to the direction of feed belt 2. Instead of a transversely-moving belt 5 the withdrawal belt may run longitudinally, i.e. in the same direction as the feed belt 2. The fleece-laying machine includes three cars, namely, a layer car 7, a storage car 8 and a balance car 9. The storage car 8 is provided with a jib 10 on which is located a conveyor belt 11 which passes between rollers 12 and 13. A further conveyor belt 14 extends from roller 15 of the storage car 8, over a roller 16 of the balance car 9 back to a roller 17 on storage car 8, and from this point to a roller 18 of the layer car 7 and back to a roller 19 of the storage car 8, and from this point again to roller 15. The conveyor belt 14 of the storage car 8 thus extends both to the balance car 9 and also to the layer car 7, the latter being movable reciprocably across the width of the withdrawal belt 5.
The belt roller 4 of the feed belt 2 is driven at a predetermined speed, preferably the doffer speed of a carding machine or the like. From the drive wheel 4a of belt roller 4 a drive chain 20 extends over a chainwheel 22 on axle 21 of the roller 16 for the conveyor belt 14, the drive chain extending over a fixed roller 23 back to the chainwheel 4a. Thus, the conveyor belt 14 is driven from a driven belt roller 4 of the feed belt 2, and the belt 11 on jib 10 of the storage car 8 is driven by roller 17 located on the storage car 8 by means of chain 24 which extends over a chainwheel on the axle of the roller 13. Thus, belt 11 is driven at the same speed as belt 14.
The layer car 7 and the balance car 9 are connected together by a tension chain 25. The tension chain 25 is attached at 26 to the balance car 9 and at 27 to the layer car 7 and extends over a roller 28 mounted on the jib 10 of storage car 8.
Layer car 7 is driven by a car traction chain 29 which passes over fixed rollers 30 and 31. The upper bight of the car traction chain 29 is rigidly connected at 29a to the layer car 7. Rotation of rollers 34 and 35 is effected by a measuring chain 36 stretched between two countersupports 37. The withdrawal rollers 34, 35 or laying rollers are connected by transmission members 38, 39 to chainwheels 40, 41 via wheels 42, 43. Chainwheels 40, 41 are provided with free wheel clutches, respectively, which operate in opposite rotary directions, insuring that the rotary direction of the laying rollers 34, 35 always remains the same when the layer car 7 changes direction. The car traction chain 29 is driven by a reversible geared motor, e.g. a DC motor.
A common drive unit is provided between the three cars, namely, the layer, storage and balance cars. The drive unit comprises a common control chain 44. The chain 44 leads from the fixed rollers 45, 46 over a fixed driven roller 47 to rollers 48 and 49 on the jib 10 of storage car 8, from this point over chainwheels 50 and 50a, one of which is driven, depending upon the direction of movement of layer car 7, and back over rollers 51, 52 and 53 located on the storage car 8. The chain wheel 50 is fixed on the same axle on which wheel 43 is located. Wheel 43, however, has a smaller diameter than the chain wheel 50. The control chain 44 also extends over chain wheel 50a which is rigidly connected to wheel 42. Roller 47 is driven through belt roller 4 by means of corresponding intermeshing gear wheels 54 and 55.
The operation of the fleece-laying machine is as follows. The fleece 56 is fed over the feed belt 2 and is then passed over roller 13 of conveyor belt 11 between the two bights of the conveyor belts 11 and 14 to the layer car 7 and between the laying rollers 34, 35 onto the withdrawal belt 5 where it is deposited in a continuous reciprocating motion on the withdrawal belt 5. FIG. 1 shows the positions of the cars at the beginning of the laying process. The peripheral speed of the belt roller 4 at the intake corresponds to the fleece speed or the doffer speed. This speed is on the one hand transmitted to the control chain 44 by means of the roller 47 and on the other hand by the drive chain 20 to the belt roller 16 of the balance car 9. The layer car 7 is set in motion via the car traction chain 29. The measuring chain 36 thus automatically sets the right chain wheel 41 of the layer car 7, with power connected to the shaft, in rotation, while the other chainwheel 40 is uncoupled, or the free wheel is effective. The control chain 44 is driven by the chainwheels 50 or 50a which run synchronously with the laying rollers 34, 35. It should be noted that the control chain 44 is driven at two different points.
When the layer car 7, seen in the plane of the drawing, moves to the right, there is imparted to the storage car 8 by the control chain 44 a movement in the same direction as that of the layer car 7 but at only half the speed. When the movement of the layer car 7 is at fleece speed, no traction is exerted on the balance car 9 either via the tension chain 25 or via the main belt 14.
When the speed of the layer car 7 is lower than that of the fleece, then there is imparted by the control chain 44 to the storage car 8 an additional movement in the direction of the movement of the layer car 7 so that the storage car 8 reaches half the fleece speed, i.e. is accelerated. The fleece 56, entering at constant speed, is therefore stored without residue by the movement of the storage car 8. As in this case the layer car 7 is moved slower than twice the speed of the storage car 8 and the main belt 14 is drawn around the rollers 19, 15 of the storage car 8. The result is that the balance car 9 moves to the right because of the traction exerted by the main belt 14.
During the movement of the layer car 7, the car speed must exceed the fleece speed, if the fleece speed at the turning point or at the beginning of the laying stretch has not been achieved. This is necessary for the medium speed of the layer car 7 to be equal to the doffer speed.
When the layer car 7 reaches fleece speed the movement of the balance car 9 to the right ceases and is transformed, on exceeding the fleece speed, through the layer car 7 into a movement to the left, this movement is achieved by traction from tension chain 25.
When it has passed over the full laying width, the layer car 7 is reversed and travels to the left. Control of the layer car 7 is effected via the car traction chain 29 which is correspondingly driven. During the reversal, the right chainwheel 41, which has transmitted the rotation caused by measuring chain 36, is uncoupled or the free wheel becomes defective and the left chainwheel 40 is coupled to the shaft.
When the speed of the layer car 7 is less than the fleece speed, the control chain 44 imparts to the storage car 8 a movement opposite in direction to that of the layer car 7. When the speed of the layer car after reversal to the left is zero, the storage car 8 continues at half the fleece speed towards the right. Only when the speed of the layer car 7 during the return is higher than half the fleece speed does the storage car 8 likewise move in the direction of the layer car 7 to the left.
The balance car 9 executes the same movements in the reverse phase as during the forward phase. When the speed of the layer car 7 is less than the fleece speed, the balance car 9 moves to the right; if it is above the fleece speed, the balance car moves to the left. When only one balance car is present the balance of the movements of the cars and of the speeds is effected by the common control chain 44 driven by the belt roller of the feed belt and by the movement of the layer car passing through the storage car 8 and the layer car 7. Alternatively, the control chain 44 can be passed to the belt roller 21 of the balance car 9 and drive chain 20 can then be eliminated.
In the further embodiment illustrated in FIGS. 6-10, an endless measuring chain 36a is provided for rotating rollers 34, 35, the drive for the endless measuring chain 36a being derived from the car traction chain 29. The measuring chain 36a is passed over the wheels 57, 58 and drive for the movable measuring chain 36 is effected from the wheel 57.
The shaft 59 carrying wheel 59 is driven by a shaft 65 to which the wheel 30 for the car traction chain 29 is non-rotarily connected. Drive is effected via chainwheel 63, chain 64 and chainwheel 60; chainwheel 60 only being half the diameter of chainwheel 63. The shaft 39 thus rotates at twice the speed and moves the measuring chain 36a at twice the speed, wheel 57 having the same diameter as wheel 30.
Chain wheel 60 and shaft 59 are releasably connected to each other by a clutch 61. Also, a freewheel device 62 is located on the shaft 59, the freewheel device being stationarily mounted and preferably fixed to the frame of the machine. The freewheel device 62 prevents rotation of shaft 59 clockwise as viewed in FIGS. 6 and 6a. Clutch 61 is engaged when the layer car 7 (FIGS. 6 and 6a) moves to the left; in this case the shaft 59 rotates anti-clockwise and the measuring chain 36a is moved at double speed relative to the speed of layer car 7. At the left turning point of layer car 7 the clutch 61 is disengaged and measuring chain 36a becomes stationary. The layer car 7 then moves to the right. Thus, there is exerted on measuring chain 36a a tractive force which would rotate shaft 59 clockwise were it not prevented by the freewheel device 62. At the right turning point (FIGS. 6 and 6a) of the layer car 7 the clutch 61 is again engaged.
Measuring chain 36a extends to the layer car 7 over chainwheel 66, 67 (FIG. 6a) which are mounted on shafts 33 and 32, respectively, alternately around the chainwheels on opposite sides thereof. When the layer car 7 reverses its direction the rotary direction of layer rollers 34, 35 remains the same.
When the layer car 7 travels to the right (FIGS. 6 and 6a), the clutch 61 is disengaged. The rotary movement of the car traction shaft 65 is not transmitted to the shaft 59. The measuring chain 36a remains stationary. The storage car 8 in this instance also moves to the right. Frictional forces exert through the synchronous chain, the chainwheels on the layer wheel and the measuring chain 36a a force on the chainwheel 57 which would turn shaft 59 clockwise. This is prevented, however, by the free wheel 62 which is stationarily mounted. When the layer car 7 is at the right reversing point, the shaft 65 is stationary for the period of reversal. At this moment the clutch 61 is engaged in order to transmit the incipient rotary movement of shaft 65 (anti-clockwise) to the shaft 59 and by means of its transmission to impart to measuring chain 36a double the layer car speed. This direction of rotation is permitted by free wheel 62.
Measures may be taken to guarantee precise reversal without requiring adjustment. The part 61 may consist of a clutch and a free wheel arranged in parallel therewith to provide the power connection between the chain wheel 60 and the shaft 59. This parallel-mounted free wheel is present in addition to the free wheel 62. When the rotary movement of the layer car shaft 65 is initiated counter-clockwise, free wheel 62 is released and practically at the same instant the power flow is produced by the free wheel in part 61. The clutch in part 61 is engaged at an optional moment in time later, but before the impulse initiated by the braking or reversing movement of the layer car 7. With this arrangement it is no longer important to engage the clutch at a predetermined point in time. When the braking or reversing procedure with change in direction of the power flow is effected, an exact transmission of the rotary speed at any moment is guaranteed by the clutch. Disengagement of the clutch must again be effected at a specific point in time. The declutching procedure, however, takes considerably less time than the clutching procedure so that the necessary switching accuracy in this reversal point is easier to achieve.
While various modifications of the above described device have been shown and described in detail, it is obvious that further modifications and changes may be made within the scope of the invention without departing from the spirit thereof. | A device is disclosed for laying fiber fleeces or the like delivered from a carding machine of the like onto a withdrawal belt driven at a predetermined speed. The device comprises a feed belt driven at a predetermined speed, storage, layer and balance cars all arranged for oscillating movements, respectively, a first continuous conveyor belt extending about rollers on the storage and layer cars and a second continuous conveyor belt extending about rollers on the storage and layer cars and extending from the storage car to a roller on the balance car. One run of each of the conveyor belts extending between the storage and layer cars confront each other for receiving the fiber fleece therebetween. Common drive means connects the storage and layer cars and further drive means extends from the feed belt to the layer car. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/892,543 filed Mar. 2, 2007, and U.S. Provisional Application No. 60/966,403 filed Aug. 28, 2007, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention relates generally to a seat assembly for a vehicle.
2. Description of the Related Art
School bus bodies are generally standardized and generally have a common width, which means that the width of seats installed in the school bus is also generally standardized. In spite of this standardized seat width, if the school bus is used to transport grade school children, which typically have a smaller stature, then each of the seats will often accommodate three passengers. On the other hand, if the school bus is used to transport larger high school children, which typically have a larger stature, then each of the seats will accommodate only two passengers on each of the seats.
Each of the seats includes a seat bottom and a seatback, which are essentially flat. Accordingly, accommodating either two or three passengers on each seat is simply a matter of the seat width being able to accommodate the combined width of passengers sitting in the seat. In other words, the seats are designed to accommodate either two or three passengers, and are not customized to accommodate a pre-determined number of passengers. This has always provided school bus operators with scheduling flexibility, and has until recently not created any problems.
Recently, however, a longstanding debate as to whether school buses should be equipped with seatbelt assemblies has intensified, with those favoring seatbelt assembly usage on the school buses now prevailing. As a result, more and more school buses are now being equipped with seatbelt assemblies. Public pressure is building to require all school buses be equipped with seatbelt assemblies. A strong consensus has already developed requiring the seatbelt assemblies include a lap/shoulder belt combination similar to designs now installed in most modern automobiles.
However, this creates a very serious problem for the school bus industry because the school bus seats are now becoming customized with equipment to accommodate either two larger passengers or three smaller passengers, but not both. If the school bus seats are equipped to accommodate the three smaller passengers, the seatbelt assembly equipment is not properly positioned for use by the larger passengers. If the school bus seats are equipped to accommodate the two larger passengers, the capacity of the school bus is reduced. The reduced capacity requires school districts to increase the number of school buses to transport the same number of children, which is an expensive option for school districts.
Accordingly, it would be advantageous to provide a seat assembly that includes seatbelt assemblies that are configured to accommodate two larger passengers or three smaller passengers.
SUMMARY OF THE INVENTION AND ADVANTAGES
The subject invention provides a seat assembly for a vehicle. The seat assembly includes a seat having a seat bottom and a seatback with the seat extending between a first side and a second side for accommodating at least one passenger. A first seatbelt is disposed in proximity to the first side of the seat and a second seatbelt is disposed in proximity to the second side of the seat. A third seatbelt is disposed between the sides of the seat. A first buckle, a second buckle, a third buckle, a fourth buckle, and a fifth buckle are disposed in proximity to the seat and arranged sequentially from the first side of the seat to the second side of the seat. A first clip is coupled with the first seatbelt and engageable with the first and second buckles for securing a first passenger in the seat with the first seatbelt. A second clip is coupled with the second seatbelt and engageable with the third and fifth buckles for securing a second passenger in the seat with the second seatbelt. A third clip is coupled with the third seatbelt and engageable with the fourth buckle for securing a third passenger in the seat with the third seatbelt.
By utilizing five buckles in concert with three seatbelts, the seat assembly may accommodate three passengers of smaller stature or two passengers of larger stature. Therefore, a single school bus, or other vehicle, utilizing this seat assembly may service both grade school children, who typically have a smaller stature, and high school children, who typically have a larger stature. Specifically, the subject invention allows both categories of passengers to be secured to the seat with a seatbelt.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 is a perspective view of a vehicle implementing a plurality of seat assemblies;
FIG. 2 is a perspective view of a seat assembly showing a seat with three seatbelts and five buckles;
FIG. 3 is a perspective view of the seat assembly without covering on a frame of the seat;
FIG. 4 is a front view of a three passenger configuration of the seat assembly showing three passengers secured in the seat;
FIG. 5 is a front view of a two passenger configuration of the seat assembly showing two passengers secured in the seat;
FIG. 6 is a front view of the seat assembly without a seatback to reveal belt height adjusters disposed within the seatback; and
FIG. 7 is a front view of the seat assembly to show multiple buckles supported by a single stem.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, a seat assembly is shown at 10 . The seat assembly 10 is typically disposed in a vehicle such as, for example, for a standard school bus 11 . Accordingly, as is known in the art, several seats assemblies 10 will be incorporated into the school bus 11 in rows, as is shown in FIG. 1 . It should be appreciated that the seat assembly 10 may be used in any type of vehicle including, for example, an automobile, an airplane, and a boat.
Referring now to FIGS. 2 and 3 , the seat assembly includes a seat 12 extending between a first side 14 and a second side 16 . The seat includes a seat bottom 18 extending generally horizontally and a seatback 20 extending generally vertically, as is commonly known. The seat bottom 18 and seatback 20 are preferably covered with a covering (not numbered) and/or cushion (not shown) over a frame (not numbered). The seat bottom 18 may include any structure commonly utilized. The seat bottom 18 typically includes the frame formed of metal or another suitable material. The seat bottom 18 may be inclined to form a ramp (not numbered) along a front edge (not numbered) for urging passengers seated in the seat 12 toward the seatback 20 and to reduce the likelihood that the passenger uncontrollably moves forward and strikes the seatback 20 in front of the passenger when the vehicle is stopped abruptly, i.e., also referred to in industry as “submarining.” The seat assembly 10 typically includes mounting pedestals 22 attached to and extending downwardly from the seat bottom. The mounting pedestals 22 may be mounted to a floor of the vehicle.
The seat assembly 10 shown in the illustrated embodiments is configured to hold one, two, or three passengers. Specifically, the seat assembly 10 optimally secures three passengers of smaller stature, e.g., grade school students, in a three passenger configuration, as shown in FIG. 4 , or two passengers of larger stature, e.g., high school students or adults, in a two passenger configuration, as shown in FIG. 5 . However, those skilled in the art will realize that the seat assembly 10 may be configured to secure additional passengers in a wider seat 12 using the teachings set forth herein.
The seat assembly 10 includes a plurality of seatbelt assemblies (not numbered) for securing one or more passengers 30 , 32 , 34 in the seat 12 . Each seatbelt assembly includes a retractor (not numbered) and a seatbelt 24 , 26 , 28 , selectively extendable from the retractor. Specifically, in the illustrated embodiment, the seat assembly 10 includes a first seatbelt 24 , a second seatbelt 26 , and a third seatbelt 28 . The first seatbelt 24 is disposed in proximity to the first side 14 of the seat 12 . The second seatbelt 26 is disposed in proximity to the second side 16 of the seat 12 . The third seatbelt 28 is disposed between the sides 14 , 26 of the seat 12 and preferably between the first and second seatbelts 24 , 26 . In the illustrated embodiments, each seatbelt 24 , 26 , 28 is supported by the seat 12 . Particularly, one end (not numbered) of each seatbelt 24 , 26 , 28 is fastened to the seat 12 . However, in alternative embodiments (not shown), one or more of the seatbelts 24 , 26 , 28 may be fastened elsewhere, such as, the floor or side walls of the vehicle.
The seat assembly 10 preferably includes a plurality of shoulder retainers 36 , 38 , 40 as can be seen in FIG. 3 . Each shoulder retainer 36 , 38 , 40 receives one of the seatbelts 24 , 26 , 28 as is well known to those skilled in the art. Each shoulder retainer 36 , 38 , 40 allows the associated seatbelt 24 , 26 , 28 to engage a shoulder area of the passenger 30 , 32 , 34 that is secured using the seatbelt 24 , 26 , 28 . In the illustrated embodiment, a first shoulder retainer 36 receives the first seatbelt 24 , a second shoulder retainer 38 receives the second seatbelt 26 , and a third shoulder retainer 40 receives the third seatbelt 28 . Each shoulder retainer 36 , 38 , 40 is operatively connected to and supported by the seat 12 , specifically, the seatback 20 . However, those skilled in the art realize other configurations where one or more of the shoulder retainers 36 , 38 , 40 are not supported by the seat 12 . Furthermore, the seat assembly 10 may be implemented without the shoulder retainers 36 , 38 , 40 such as with seatbelts 24 , 26 , 28 securing only the waist of the passenger 30 , 32 , 34 , i.e., a “lap belt”.
The seat assembly 10 preferably also includes at least one belt height adjuster 42 , 44 , as is best seen in FIG. 6 . Each belt height adjuster 42 , 44 supports one of the shoulder retainers 36 , 38 and allows adjustment of the shoulder retainer 36 , 38 to accommodate passengers of various sizes. Specifically, each belt height adjuster 42 , 44 defines a slot 43 , 45 , such that the shoulder retainer 36 , 38 may move generally vertically. In the illustrated embodiment, a first belt height adjuster 42 supports the first shoulder retainer 36 and a second belt height 44 adjuster supports the second shoulder retainer 38 . The third shoulder retainer 40 is not supported by a belt height adjuster in the illustrated embodiment since it is contemplated that the third seatbelt 28 will be typically only used by a smaller-stature passenger. However, implementation of a belt height adjuster for the third should retainer 40 , of course, may be achieved.
More specifically, with respect to the belt height adjuster 42 , 44 , as best shown in FIG. 6 , the seatback 20 includes a seatback frame (not numbered). The seatback frame defines a track and a plurality of indentations along the track. The belt height adjuster 42 , 44 includes a slider slideably engaging the track and a pin selectively engageable with the indentations for fixing the slider at fixed positions along the seatbelt frame. It should be appreciated the embodiment including the indentations along the track is exemplary and that the movement of the belt height adjuster 42 , 44 along the seatback frame can be accomplished in any fashion without departing from the nature of the present invention. For example, the belt height adjuster 42 , 44 can be adjustable along an infinite number of positions along the seatback frame and can be maintained in any of the infinite number of positions by frictionally engaging the seatback frame.
The seatback frame includes three towers spaced from each other along the seat bottom 18 . More specifically, two of the towers are disposed on opposing ends of the seat bottom 18 and one of the towers is disposed on the seat bottom 18 approximately ⅓ of a distance from one to the other of the opposing ends. The towers each define a channel. The respective retractor is mounted at a bottom of the tower in the channel and the respective seatbelt 24 , 26 , 28 extends from the retractor to the shoulder retainer 36 , 38 , 40 in the channel. Specifically, the seatback frame has a first edge extending along an axis, a second edge spaced from the first edge and extending along the axis, and a surface extending from the first edge to the second edge defining the channel between the first edge and the second edge.
As best shown in FIG. 3 , the seat assembly 10 includes a rigid cover (not numbered) having an inner surface defining a void and the void receives the seatback frame. The rigid cover provides a surface for the passengers to rest their back against. The rigid cover rigidly couples the three towers to each other. The inner surface extends from the first edge to the second edge of each tower for enclosing the seatbelt 24 , 26 , 28 in the channel between the retractor and the shoulder retainer 36 , 38 , 40 . Specifically, the inner surface of the rigid cover contacts the first and second edges of each tower.
The cover defines an opening and the seatbelt 24 , 26 , 28 extends from the channel through the opening. The belt height adjusters 42 , 44 are selectively moveable along the opening.
The cover structurally reinforces the seatback 20 . In other words, the cover ties together the towers to reinforce the seatback 20 . The cover is typically formed of plastic; however, it should be appreciated that the cover may be formed of any material and by any method.
The seat assembly 10 further includes a plurality of buckles 46 , 48 , 50 , 52 , 54 . Specifically, the seat assembly 10 includes a first buckle 46 , a second buckle 48 , a third buckle 50 , a fourth buckle 52 , and a fifth buckle 54 . The buckles 46 , 48 , 50 , 52 , 54 are disposed in proximity to the seat 12 and arranged sequentially from the first side 14 to the second side 16 of the seat 12 .
In the illustrated embodiment, the second and third buckles 48 , 50 are preferably positioned adjacent one another as a first pair of buckles (not numbered) and the fourth and fifth buckles 52 , 54 are preferably positioned adjacent one another as a second pair of buckles (not numbered). The first pair of buckles, i.e., the second and third buckles 48 , 50 , are preferably disposed about halfway between the first and second sides 14 , 16 of the seat 12 . The second pair of buckles, i.e., the fourth and fifth buckles 52 , 54 , are preferably disposed about a third of the way across the seat 12 from the second side 16 . The first buckles 46 is preferably disposed about a third of the way across the seat 12 from the first side 14 .
A clip 56 , 58 , 60 for engaging with one of the buckles 46 , 48 , 50 , 52 , 54 is coupled to each seatbelt 24 , 26 , 28 as is well known to one skilled in the art. Specifically, in the illustrated embodiment, a first clip 56 is coupled with the first seatbelt 24 for engaging the first buckle 46 or the second buckle 48 . A second clip 58 is coupled with the second seatbelt 26 for engaging the third buckle 50 or the fifth buckle 54 . A third clip 60 is coupled with the third seatbelt 28 for engaging the fourth buckle 46 .
The above described correlation of specific clips to specific buckles allows the seat assembly 10 of the subject invention to securely accommodate one, two, three passengers. Specifically, the seat assembly 10 presents both a two-passenger configuration and a three-passenger configuration. Clearly, a single passenger could utilize either configuration. Furthermore, two passengers could also utilize the three-passenger configuration.
The three-passenger configuration is preferably suited for three passengers 30 , 32 , 34 having smaller statures, as shown in FIG. 4 . In this configuration, the first, fourth, and fifth buckles 46 , 52 , 54 , which are preferably disposed a third of the way across the seat 12 from one of the sides 14 , 16 are utilized. Specifically, the first clip 56 is engageable with the first buckle 46 to secure a first passenger 30 to the seat 12 with the first seatbelt 24 . The second clip 58 is engageable with the fifth buckle 54 to secure a second passenger 32 with the second seatbelt 26 . The third clip 60 is engageable with the fourth buckle 52 to secure a third passenger 34 with the third seatbelt 28 .
The two-passenger configuration is preferably suited for two passengers 30 , 32 having larger statures, as shown in FIG. 5 . In this configuration, the first clip 56 is engageable with the second buckle 48 to secure the first passenger 30 with the first seatbelt 24 and the second clip 58 is engageable with the third buckle 50 to secure the second passenger 32 .
Preferably, each clip 56 , 68 , 60 is engageable only with certain buckles 46 , 48 , 50 , 52 , 54 to insure that each passenger 30 , 32 , 34 may be properly secured in the seat 12 . Specifically, in the configurations of the illustrated embodiment, the first clip 56 is keyed to engage only with the first buckle 46 or the second buckle 48 , the second clip 58 is keyed to engage only with the third buckle 50 or the fifth buckle 54 , and the third clip 60 is keyed to engage only with the fourth buckle 52 . There are numerous techniques known to those skilled in the art to accomplish the keying of the clips such that they only engage with certain buckles. For instance, each clip typically forms a hole (not numbered) which allows connection to the buckle. The size and/or position of this hole may unique to each clip 56 , 58 , 60 such that each clip 56 , 58 , 60 only engages with the proper buckle 46 , 48 , 50 , 52 , 54 .
The seat assembly 10 may use a visual coding technique to match each clip 56 , 58 , 60 up with the proper buckle 46 , 48 , 50 , 52 , 54 . The visual coding technique may be implemented as an alternative to the keying of the clips 56 , 58 , 70 describe above or in concert with the keying of the clips 56 , 58 , 60 . Specifically, in the illustrated embodiment, the first clip 56 is visually coded with the first and second buckles 46 , 48 , the second clip 58 is visually coded with the third and fifth buckles 50 , 54 , and the third clip 60 is visually coded with the fourth buckle 52 . The visual coding allows the passenger to quickly and easily match up each clip 56 , 58 , 60 with its corresponding buckle 46 , 48 , 50 , 52 , 54 . As one example, the visual coding may be implemented as color coding such that at least a portion of corresponding clips 56 , 58 , 60 and buckles 46 , 48 , 50 , 52 , 54 have a similar color. Another example of visual coding includes text printed on or embedded on the clips 56 , 58 , 60 and buckles 46 , 48 , 50 , 52 , 54 .
Preferably, as shown in FIGS. 2 , 4 , and 5 , the seatback defines a plurality of cavities 62 , 64 , 66 for storing and housing the buckles 46 , 48 , 50 , 52 , 54 when the buckles 46 , 48 , 50 , 52 , 54 are not in use. Specifically, a first cavity 62 houses the first buckle 46 , a second cavity 64 houses the second and third buckles 48 , 50 , and a third cavity 66 houses the fourth and fifth buckles 58 . This storage allows the buckles 46 , 48 , 50 , 52 , 54 to be moved away from contact with the passengers 30 , 32 , 34 to enhance their comfort while seated in the seat 12 . In the three-passenger configuration, the second and third buckles 48 , 50 are stored to avoid contact with the third passenger 34 . In the two-passenger configuration, the first buckles 46 is stored to avoid contact with the first passenger 30 and the fourth and fifth buckles 52 , 54 are stored to avoid contact with the second passenger 32 .
The seat assembly 10 also includes a plurality of stems 70 with each stem 70 supporting at least one of the buckles 46 , 48 , 50 , 52 , 54 . In one embodiment, as shown in FIGS. 1-6 , each buckle 46 , 48 , 50 , 52 , 54 is supported by a single stem 70 . In another embodiment, as shown in FIG. 7 , the second and third buckles 48 , 50 are supported by a single stem 70 and the fourth and fifth buckles 52 , 54 are supported by a single stem.
The seat assembly 10 further includes a plurality of hinges 72 with each hinge 72 operatively connected to one of the stems 70 . This allows the at least one buckle that is supported by the stem 70 to move between a storage position and a usage position. In the storage position, the buckle 46 , 48 , 50 , 52 , 54 is positioned in one of the cavities 62 , 64 , 66 . Specifically, as can be seen in FIG. 2 , the first buckle 46 is positioned in the first cavity 62 , the second and third buckles 48 , 50 are positioned in the second cavity 64 , and the fourth and fifth buckles 52 , 54 are positioned in the third cavity 66 . In the usage position the buckle 46 , 48 , 50 , 52 , 54 is positioned out of one of the cavities 62 , 64 , 66 .
Each stem 70 , as well as the buckle or buckles 46 , 48 , 50 , 52 , 54 supported thereby, is biased toward its respective cavity 62 , 64 , 66 by a spring 74 . Specifically, the seat assembly 10 includes a plurality of springs 74 , with each spring 74 operatively connected to one of the stems 70 . Therefore, when the buckle or buckles 46 , 48 , 50 , 52 , 54 are not being utilized, i.e., connected to a clip 56 , 58 , 60 , the buckle or buckles 46 , 48 , 50 , 52 , 54 are moved into the storage position.
The present invention has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims. | A seat assembly for a vehicle, such as a school bus, accommodates two or three passengers, depending on the size and stature of the passengers. The seat assembly is equipped with three seatbelts and five buckles spaced along a seatback. When three passengers are utilizing the seat assembly, each of the three seatbelts and three of the buckles are utilized. When two passengers are utilizing the seat assembly, two of the seatbelts and the remaining two buckles are utilized. The seatbelts and buckles are visually coded and/or keyed to prevent improper use. When the buckles are not being utilized, they are housed in cavities formed in the seatback to avoid interference with the passengers. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus in which a plurality of piezoelectric transducers are arranged in a predetermined direction so as to transmit and receive ultrasonic waves to obtain a tomographic image on the inside of the subject, and more particularly to an ultrasonic diagnostic apparatus adopting such a scheme that a sector scan is electronically performed.
2. Description of the Related Art
Hitherto, there has been used an ultrasonic diagnostic apparatus in which ultrasonic waves are transmitted toward the subject, specially a living body and ultrasonic waves reflecting from a tissue within the living body are received by piezoelectric transducers to generate received signals, and an image of the living body is displayed on the basis of the received signals, thereby facilitating a diagnostic of an intestinal disease or the like in the living body.
FIG. 23 is a schematic diagram showing a functional structure of an ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus 100 is provided with, for example, 64 piezoelectric transducers (hereinafter, it may happen that these are each referred to as "element") 12 -- 1, 12 -- 2, . . . , 12 -- 64, which are arranged as a strip. Those elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 are applied to a body surface of the subject (not illustrated), and then a transmitting circuit 102 sends out pulse signals to the piezoelectric transducers in their associated timings, respectively. The pulse signals are converted into high voltage pulses by the associated transmitting driver 103 -- 1, 103 -- 2, . . . , 103 -- 64, respectively. The converted high voltage pulses are applied to the elements 12 -- 1, 12 -- 2, . . . , 12 -- 64, respectively, so that ultrasound beams emanate from the elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 toward the inside of the subject.
The ultrasonic waves reflecting from the inside of the subject again return to the elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 and are received thereat. Signals, which are generated through receiving by the elements 12 -- 1, 12 -- 2, . . . , 12 -- 64, are amplified suitably by receiving amplifiers 104 -- 1, 104 -- 2, . . . , 104 -- 64, respectively, and then supplied to a beamformer circuit 105. The beamformer circuit 105 is arranged to delay the respective entered received signals and then to add the respective delayed received signals, so that the received signals can be generated along the ultrasound beams extending into the subject. The added received signals, which are outputted from the beamformer circuit 105, are applied to a signal transforming circuit 106 so as to be transformed into a displaying signal. The displaying signal outputted from the signal transforming circuit 106 is applied to a CRT display 107, so that a tomographic image 110 on the inside of the subject is displayed on a screen of the display 107.
Incidentally, when the piezoelectric transducers (elements) 12 -- 1, 12 -- 2, . . . , 12 -- 64 are generally named, they are denoted as the piezoelectric transducers (elements) 12, hereinafter. This is the similar as to the matter of the transmitting driver 103 -- 1, 103 -- 2, . . . , 103 -- 64, and the receiving amplifiers 104 -- 1, 104 -- 2, . . . , 104 -- 64.
FIG. 24 is a typical illustration of an example showing a relationship between an arrangement of the piezoelectric transducers and reflecting points of ultrasonic waves within the subject. In this figure, the axis of abscissas X denotes an arrangement direction of 64 pieces of piezoelectric element 12 applied to a body surface, and the axis of ordinates Z and the clinoaxis Z' denote the directions (each of them is referred to as a scan line) of traveling of ultrasound beams within the subject. Here, it is assumed that an acoustic velocity within the subject is uniform independently of a place.
In case of the formation of ultrasound beams having a focus at a point P1 within the subject, the transmitting circuit 102 (Cf. FIG. 23) sends out transmission pulse signals to the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 in their associated timings, respectively, such that the transmission pulse signals are delayed in accordance with a delay pattern corresponding to an arc R1 described with the point P1 in the center so that the ultrasonic waves emitted from the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 arrive simultaneously on the arc R1, in such a manner that taking account of an acoustic velocity within the subject, for example, the piezoelectric elements 12 -- 31 and 12 -- 32 at the center radiate the ultrasonic waves at the time point when the ultrasonic waves emitted from the piezoelectric elements 12 -- 1 and 12 -- 64 at the both ends arrive on the arc R1.
In a similar fashion to that of the formation of ultrasound beams having a focus at a point P1, ultrasound pulse beams having focuses at points P2 and P3, respectively, which travel toward a scan line Z direction, are formed by means of generating by the transmitting circuit 102 transmission pulse signals delayed in accordance with delay patterns corresponding to arcs R2 and R3, respectively.
Further, it is possible to form not only a scan line extending to a direction (Z direction) perpendicular to the arrangement direction X of the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 but also a scan line extending to a direction (Z' direction) oblique with respect to the arrangement direction X. Ultrasound pulse beams having focus at a point P4, which travel toward a scan line Z' direction, are formed through an adjustment of delay patterns for transmission pulse signals so that the ultrasonic waves emitted from the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 arrive simultaneously on an arc R4 described with the point P4 in the center.
This is the similar as to the matter of receiving. For example, the ultrasonic waves reflecting from the point P1 travels toward the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 with dispersion and arrive simultaneously on the arc R1. Here, the received signals involved in the ultrasonic waves reflecting from the point P1, which are derived from, for example, the piezoelectric elements 12 -- 31 and 12 -- 32 of the center, are delayed until the ultrasonic waves reflecting from the point P1 are received by the piezoelectric elements 12 -- 1 and 12 -- 64 of the both ends. In this manner, the respective received signals are delayed through a delay pattern corresponding to the arc R1 and the delayed received signals are added, thereby forming at the receiving end the equivalent ultrasound beams having a focus at a point P1 and extending to the scan line Z direction.
In a similar fashion to that of the formation of ultrasound beams having a focus at a point P1 at the receiving end, ultrasound beams having focuses at points P2 and P3, respectively, which extend to the scan line Z direction, are formed at the receiving end by means of delaying the respective received signals in accordance with delay patterns corresponding to arcs R2 and R3, respectively.
Further, ultrasound beams having focus at a point P4, which extend to the scan line Z' direction, are formed at the receiving end by means of delaying the respective received signals in accordance with a delay pattern corresponding to an arc R4.
Here, the ultrasonic waves transmitted from the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 toward the scan line Z direction first arrive at a shallow point P3 within the subject, then at a point P2 and finally at a point P1. Consequently, the ultrasonic waves reflecting from the point P3 reach the elements 12 earlier than the ultrasonic waves reflecting from the point P2. Likewise, the ultrasonic waves reflecting from the point P2 reach the elements 12 earlier than the ultrasonic waves reflecting from the point P1.
Hence, this aspect is utilized for a control of delay patterns in such a way that a delay pattern for the respective received signals derived through the piezoelectric elements 12 -- 1, 12 -- 2, . . . , 12 -- 64 is adjusted, in timing of receipt of the ultrasonic waves reflecting from the point P3, to provide a delay pattern corresponding to the arc R1; in timing of receipt of the ultrasonic waves reflecting from the point P2, to provide a delay pattern corresponding to the arc R2; and in timing of receipt of the ultrasonic waves reflecting from the point P1, to provide a delay pattern corresponding to the arc R3. In this manner, it is possible to implement a so-called receiving dynamic focus in which a focal point at the receiving end is sequentially shifted, as P1→P2→P3, extending to the scan line Z direction.
FIG. 25 is an illustration showing a pattern of weighting (amplification factor of each of the receiving amplifiers 104 -- 1, 104 -- 2, . . . , 104 -- 64) for the respective received signals derived through the elements 12 -- 1, 12 -- 2, . . . , 12 -- 64.
It is assumed that the center of a group of the elements (receiving aperture) for use in receiving is given by X=0. As a function representative of a pattern of weighting, generally, Gaussian function, which is expressed by formula (1), is adopted.
g(x)=exp{-α.sup.z (X/XO).sup.2 } (1)
where
α: weighting factor, and
XO: coordinates of end of receiving aperture.
The weighting factorα serves to determine a ratio of gain of the received signal derived through an element located away from the center (X=0) of the aperture.
It is known that the above-mentioned weighting of the received signals may reduce a side-lobe-level of the received ultrasound beams, thereby enhancing resolution.
Incidentally, while Gaussian function is shown in formula (1) as the weighting function, it is noted that the weighting function is not always Gaussian function. It is known that the use of, for example, a trapezium-like shaped weighting function, which approximates to Gaussian function, may also bring the substantially same result.
FIG. 26 is an illustration showing an example in which a size D (the number of elements used for receiving) of the receiving aperture is varied in a state that weighting is fixed.
It is also known that a receiving is performed, as shown in FIG. 26, temporarily using a part of the arranged elements for the purpose of, for example, a control of the intensity and resolution of the received signals at a shallow point and a deep point within the subject, but not using all of the arranged 64 pieces of elements.
This is similar to the matter of a transmission. It is known that a transmission is performed, temporarily using a part of the arranged elements for the purpose of, for example, a control of the intensity of the ultrasonic waves at a shallow point and a deep point within the subject, and a beam width of the transmitting ultrasound beam. There is also known such a technique of weighting that in transmission, in a similar fashion to that of the weighting shown in FIG. 26, the number of pulses of the transmission pulse signal, a pulse voltage and the like are controlled to transmit the ultrasonic waves, which are mutually different in an intensity, from the respective elements in the transmission aperture (a group of elements for use in transmission).
Next, taking account of the various techniques as to the ultrasonic diagnostic system as mentioned above, there will be described the conventional electronic sector scan type of ultrasonic diagnostic apparatus, which is used, for example, for observation of the heart, and the problems involved in such an apparatus.
The sector scan implies such a scanning scheme that as explained referring to FIG. 24, a scan line extending to a direction oblique with respect to the arrangement direction of the elements is formed and sequentially varied in the direction of the scan line so as to spread in a sector configuration in its entirety. The use of such a sector scan serves to form a sector shaped tomographic image 110 as illustrated in the screen of the CRT display 107 in FIG. 23.
FIG. 27 is a typical illustration showing the state of transmitting and receiving of the ultrasonic waves through adjacent ribs toward the heart using the conventional electronic sector scheme of ultrasonic diagnostic apparatus.
According to the conventional typical electronic sector scan type of ultrasonic diagnostic apparatus, a sector shaped tomographic image is formed in such a manner that as seen from FIG. 27, an amount of delay of each of the elements 12 applied to a body surface 11 at the time of transmitting and receiving is controlled so that the ultrasound beams are deflected right and left with the center 1 of the elements 12 in the center. In this manner, in order to form the tomographic image of the heart, a scan is performed, placing a group of elements between rib 10-to-rib 10 each being of 10 mm in an adult. Consequently, as to the aperture with respect to the scan direction (an arrangement direction of the elements, or the right and left direction in FIG. 27), there are two conflicting requirements, one of which is involved in a requirement in which the aperture is formed in size as smaller as possible in view of the fact that the scan is performed through adjacent ribs, another concerns a requirement in which the aperture is formed in size as large as possible to obtain a penetration. As common grounds, usually, the aperture with respect to the scan direction is set up with a size of the order of 10 mm-20 mm. Hence, the scan lines (areas 20) of the edge portions of the sector configuration, where the ultrasonic waves are larger in the deflection angle, involves such problems that the ultrasonic waves are obstructed by the ribs 10 and as a result an observer cannot see portions deeper than the ribs 10, and further multiple reflection echoes due to reflection from the ribs appear and as a result overall image is deteriorated.
FIG. 28 is a typical illustration showing a technique of removing or reducing a bad influence of the ribs, which technique is proposed in, for example, Japanese Utility Model Laid Open Gazette No. 114019/1990.
According to the proposal as noted above, arranging the piezoelectric transducers 12 as a concave sets up the center of curvature (an intersection of scan line-to-line) 2 of the transmitting and receiving wave surface within the human body, and a so-called linear scan is carried out through a ultrasonic propagation medium 14 within a water sack 15, thereby implementing the sector scan in which the center of curvature 2 is placed in the center independent of the ribs 10. However, according to this scheme, the ultrasonic waves are reflected on a boundary between a body surface 11 and the ultrasonic propagation medium 14 and as a result multiple reflection echoes emanate, and thus it is difficult to obtain a good image.
Japanese Patent Publication No. 12971/1992 proposes a method of improving the problem as to the above-mentioned multiple reflection.
FIGS. 29 and 30 are each a typical illustration useful for understanding the proposal disclosed in Japanese Patent Publication No. 12971/1992.
According to the system of this proposal, the scan is performed in such a manner that the ultrasound beams pass through substantially a fixed point (center 2) within the human body, using fixed or semi-fixed delay elements 17 each provided for the associated element, so as to obtain the equivalence to such a situation that as in the related art shown in FIG. 28, the elements 12 are arranged on the arc of a radius R from the center 2 of the sector scan within the human body. In this case, the focal position of the ultrasound beams is equal to the position of the center 2 within the human body. On the other hand, it is necessary for observation of the heart to provide a focus position of the order of 80-100 mm, and thus variable delay elements 19 for use in alteration of the focal position are used in combination. With respect to the aperture width, as shown in FIG. 30, there is provided the same effective aperture (L1'=L1·COS (θ)=L0) on each scan line. The number of elements forming an aperture on each scan line is about 7-9 pieces.
However, this system is poor in the number of transmitting and receiving elements and thus poor in resolution and penetration. In case of the general electronic sector type, the aperture is of about 20 mm, and is comprised of 60 pieces of element. According to such general electronic sector type, 50 pieces of element are used for transmission, and about overall elements are used for receiving. Consequently, according to the conventional systems as proposed in FIGS. 29 and 30, the aperture area (the number of transmitting and receiving elements) is too little to form the converged ultrasound beam, and thus it is apparent that resolution is reduced and penetration is not attained.
SUMMARY OF THE INVENTION
In view of the foregoing, it is therefore an object of the present invention to provide an ultrasonic diagnostic apparatus capable of solving the above-mentioned problems, preventing deterioration of an image by reducing an influence of reflection of the ultrasonic waves from the ribs, and forming a good image improved in resolution.
To achieve the above-mentioned objects, according to the present invention, there is provided an ultrasonic diagnostic apparatus, as the first type of system, comprising:
transmitting and receiving means, having a plurality of piezoelectric transducers are arranged in a predetermined arrangement direction, for sequentially transmitting ultrasound beams along a plurality of scan lines from the piezoelectric transducers into a subject and for sequentially receiving ultrasonic waves along a plurality of scan lines with the piezoelectric transducers; and
display means for displaying a tomographic image of the subject on the basis of received signals generated from said transmitting and receiving means,
wherein said transmitting and receiving means are arranged to transmit and receive ultrasonic waves along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a first predetermined point within the subject apart from said piezoelectric transducers, and performs transmitting and/or receiving of ultrasonic waves using a larger number of said piezoelectric transducers for transmitting and receiving of ultrasonic waves along the scan lines nearer a central part of the sector configuration.
It is preferable, in the first type of ultrasonic diagnostic apparatus as recited above, that a distance d 1 between said piezoelectric transducers and said first predetermined point is expressed by 1 mm≦d 1 ≦6 mm.
Further, it is preferable that said transmitting and receiving means includes a scan line intersection shift means for shifting said first predetermined point to said arrangement direction and a depth direction within the subject.
To achieve the above-mentioned objects, according to the present invention, there is provided an ultrasonic diagnostic apparatus, as the second type of system, comprising:
transmitting and receiving means, having a plurality of piezoelectric transducers are arranged in a predetermined arrangement direction, for sequentially transmitting ultrasound beams along a plurality of scan lines from the piezoelectric transducers into a subject and for sequentially receiving ultrasonic waves along a plurality of scan lines with the piezoelectric transducers; and
display means for displaying a tomographic image of the subject on the basis of received signals generated from said transmitting and receiving means,
wherein said transmitting and receiving means are arranged to transmit ultrasonic waves along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a second predetermined point within the subject apart from said piezoelectric transducers, and receive ultrasonic waves along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a third predetermined point within the subject, the third predetermined point being set up to a place deeper than the second predetermined point.
It is preferable, in the second type of ultrasonic diagnostic apparatus as recited above, that a distance d 2 between said piezoelectric transducers and said second predetermined point is expressed by 1 mm≦d 2 ≦3 mm, and a distance d 3 between said piezoelectric transducers and said third predetermined point is expressed by d 2 <d 3 ≦6 mm.
Further, it is preferable that said transmitting and receiving means includes scan line intersection shift means for shifting said second predetermined point and said third predetermined point to said arrangement direction and a depth direction within the subject.
To achieve the above-mentioned objects, according to the present invention, there is provided an ultrasonic diagnostic apparatus, as the third type of system, comprising:
transmitting and receiving means, having a plurality of piezoelectric transducers are arranged in a predetermined arrangement direction, for sequentially transmitting ultrasound beams along a plurality of scan lines from the piezoelectric transducers into a subject and for sequentially receiving ultrasonic waves along a plurality of scan lines with the piezoelectric transducers; and
display means for displaying a tomographic image of the subject on the basis of received signals generated from said transmitting and receiving means,
wherein said transmitting and receiving means are arranged to transmit ultrasonic waves along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a fourth predetermined point on said piezoelectric transducers, and receive ultrasonic waves along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a fifth predetermined point within the subject apart from said piezoelectric transducers.
It is preferable, in the third type of ultrasonic diagnostic apparatus as recited above, that a distance d 5 between said piezoelectric transducers and said fifth predetermined point is expressed by 1 mm≦d 5 ≦6 mm. Further, it is preferable, in the third type of ultrasonic diagnostic apparatus as recited above, that said transmitting and receiving means includes scan line intersection shift means for shifting said fourth predetermined point to said arrangement direction, and for shifting said fifth predetermined point to said arrangement direction and a depth direction within the subject.
Also in the apparatus according to the second or third type of system as recited above, similar to the apparatus according to the first type of system as recited above, it is preferable that said transmitting and receiving means performs transmitting and/or receiving of ultrasonic waves using a larger number of said piezoelectric transducers for transmitting and receiving of ultrasonic waves along the scan lines nearer a central part of the sector configuration.
Further, in the apparatus according to the first, second or third type of system as recited above, it is preferable that said transmitting and receiving means is arranged to form received signal on each scan line in such a manner that a larger weighting is applied to received signals derived from the piezoelectric transducers arranged nearer a central part of a receiving aperture comprised of a plurality of the piezoelectric transducers which serve to receive ultrasonic wave of the associated scan line, and then the signals subjected to the weighting process are added. And it is also preferable that said apparatus further comprises second transmitting and receiving means for transmitting and receiving ultrasonic waves along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a predetermined point on said piezoelectric transducers, said second transmitting and receiving means being adapted to be replaced by said transmitting and receiving means on a switching basis.
Furthermore, in the apparatus according to the first, second or third type of system as recited above, it is preferable that said transmitting and receiving means is arranged to perform transmission of ultrasonic waves in such a manner that a higher energy of electric power is supplied to said piezoelectric transducers for transmitting of ultrasonic waves along scan lines nearer edge portions of said sector configuration. And it is preferable that said transmitting and receiving means is arranged to amplify the received signals derived through said piezoelectric transducers with a higher amplification factor for receiving of ultrasonic waves along scan lines nearer edge portions of said sector configuration.
With respect to display means, in the apparatus according to the first, second or third type of system as recited above, it is preferable that said display means displays a relative position of said piezoelectric transducers to a tomographic image of the subject, along with the tomographic image.
Further, in the apparatus according to the first, second or third type of system as recited above, in a case where there is provided the second transmitting and receiving means in addition to said transmitting and receiving means, it is acceptable that said display means displays a tomographic image of the subject based on the received signals derived through said transmitting and receiving means, and in addition a partial image of a tomographic image of the subject based on the received signals derived through said second transmitting and receiving means, said partial image being displayed on a screen area, in which the former tomographic image is not displayed, in alignment of coordinates with the former tomographic image.
Furthermore, in the apparatus according to the first, second or third type of system as recited above, it is a preferable aspect that said display means displays a tomographic image having an angle defined by two scan lines of both the edges of said sector configuration, said angle exceeding 90°. And it is acceptable that said display means displays a first tomographic image of the subject based on the received signals derived through said transmitting and receiving means, and in addition a screen area adapted to display a second tomographic image of the subject based on received signals which will be derived when ultrasonic waves are received along a plurality of scan lines which are sequentially deflected as a sector in the arrangement direction and pass through a predetermined point fixed on said piezoelectric transducers or movable on said piezoelectric transducers in the arrangement direction, said screen area being displayed in alignment of coordinates with the first tomographic image.
According to the conventional scan scheme, it is obliged to be influenced by the ribs in transmitting and receiving of ultrasonic waves, since the ribs appear on scan lines. For this reason, according to the ultrasonic diagnostic apparatus, as the first type of system, a sector center is set up within the human body (between adjacent ribs) and the sector scan is implemented with the set up position in the center. A positional relationship between the human body and the ribs is expressed such that a distance from the body surface to the ribs is of the order of 0-1 mm; a shape of a rib is almost elliptical with a dimension of the order of 12 mm in width and of the order of 8 mm in thickness; and an opening of adjacent ribs is about 10 mm. In view of such a positional relationship, if the sector center is set up to 1-6 mm in depth, preferably, 4 mm-5 mm within the human body, it is possible to perform a scan avoiding the ribs. Consequently, if transmitting and receiving of ultrasonic waves are effected through shifting a starting point of a scan line (an intersection of the scan line and the arranged piezoelectric transducers) in accordance with a deflecting angle of the scan line concerned, in such a manner that the respective scan lines intersect at a predetermined point of 1-6 mm (preferably 4 mm-5 mm) in depth within the human body, it is possible to implement a sector scan with a point (the first point) within the human body in the center.
With respect to the aperture (the number of elements) for transmitting and receiving, hitherto, the number of elements for transmitting and receiving is given by 7 to 9 elements (cf. FIGS. 29 and 30) so that the same aperture is provided for the respective scan lines. On the other hand, according to the ultrasonic diagnostic apparatus, as the first type of system of the present invention, transmitting and/or receiving of ultrasonic waves are performed using a larger number of said piezoelectric transducers for transmitting and receiving of ultrasonic waves along the scan lines nearer a central part of the sector configuration. Thus, according to the ultrasonic diagnostic apparatus, as the first type of system of the present invention, resolution and penetration are improved comparing with the conventional system. In this case, the aperture of the edge portion is smaller than that of the central part. As a result, resolution and penetration will be reduced relatively comparing with the central part. However, it is possible to avoid such a reduction by means of increasing an energy (voltage, the number of pulses and the like) for driving the piezoelectric transducers for scan lines nearer the edge portion, or increasing an amplification factor of the received signal for scan lines nearer the edge portion.
Further, moving the first predetermined point as the pivot of a sector shaped scan line to the depth direction within the subject makes it possible to control the first predetermined point to a suitable depth even if individuality (physique) of the subject is varied. Furthermore, moving the first predetermined point to the arrangement direction make it possible to observe with greater resolution one of the right and the left of the tomographic image in accordance with the moving direction.
In this manner, according to the ultrasonic diagnostic apparatus, as the first type of system of the present invention, it is possible to perform transmitting and receiving of ultrasonic waves without obstruction, thereby suppressing multiple reflection from the ribs and deterioration of images. And in addition, it is possible to improve resolution and penetration.
According to the ultrasonic diagnostic apparatus, as the second type of system of the present invention, a cross point (the second predetermined point) as to transmitting is set up shallowly more than a cross point (the third predetermined point) as to receiving. This feature permits a less moving amount of the cross point of scan lines in transmitting with the piezoelectric transducers, thereby spreading a transmitting aperture also as to the scan lines at the sector shaped edge portions. Therefore, comparing with the first type of ultrasonic diagnostic apparatus, while it is influenced somewhat by the ribs, it is possible to enhance resolution of the edge portions and intensity of the received signals by the corresponding enlargement of the transmitting aperture.
According to the ultrasonic diagnostic apparatus, as the third type of system of the present invention, with respect to transmission, in a similar fashion to that of the conventional system (cf. FIG. 27), a cross point (the fourth predetermined point) of the scan lines is set up on the piezoelectric transducers, and on the other hand, with respect to receiving only, a cross point (the fifth predetermined point) of the scan lines is set up within the subject away from the piezoelectric transducers. According to the ultrasonic diagnostic apparatus, as the third type of system of the present invention, comparing with the second type of ultrasonic diagnostic apparatus, while it is more influenced somewhat by the ribs, it is possible to enhance resolution of the edge portions and intensity of the received signals by the corresponding. Further, for example, if the above-mentioned receiving dynamic focus is used in combination, it is possible to form a tomographic image, similar to the conventional one, in which a point coming in contact with the piezoelectric transducers is provided as the pivot of the sector configuration. In this case, it is possible to perform a display which will give little a sense of disharmony for an operator who is familiar with the conventional tomographic image in observation.
Further, positioning a cross point of scan lines for transmitting and receiving within the subject away from the piezoelectric transducers makes it possible, even in a case where a sector shaped tomographic image is formed with the point located away from the piezoelectric transducers in the center, to clear a distinction from the screen of the conventional tomographic image in such a manner that a relative position of the piezoelectric transducers is displayed on the screen, the tomographic image concerned is superposed on the conventional sector shaped tomographic image formed with a point coming in contact with the piezoelectric transducers in the center, or a display image area of the conventional sector shaped tomographic image is clarified. Thus, it is possible, for an operator who is familiar with the conventional tomographic image in observation, to avoid mistake as to the corresponding between the tomographic image and the position within the subject.
Incidentally, according to the present invention, it is possible to set up the center of a sector configuration of a tomographic image inside the subject. Consequently, it is possible to display a wider-angle of tomographic image than 90° of opening angle of tomographic image according to the conventional scheme. The display of such a wide-angle of tomographic image allows observation and diagnostic over the wide area particularly as to a deep portion within the subject.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the first ultrasonic diagnostic apparatus of the present invention;
FIG. 2 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the first ultrasonic diagnostic apparatus of the present invention;
FIG. 3 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the first ultrasonic diagnostic apparatus of the present invention;
FIG. 4 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the first ultrasonic diagnostic apparatus of the present invention;
FIG. 5 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the second ultrasonic diagnostic apparatus of the present invention;
FIG. 6 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the second ultrasonic diagnostic apparatus of the present invention;
FIG. 7 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the second ultrasonic diagnostic apparatus of the present invention;
FIG. 8 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the second ultrasonic diagnostic apparatus of the present invention;
FIG. 9 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the third ultrasonic diagnostic apparatus of the present invention;
FIG. 10 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the third ultrasonic diagnostic apparatus of the present invention;
FIG. 11 is a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the third ultrasonic diagnostic apparatus of the present invention;
FIG. 12 is a typical illustration showing an example in which the present invention is applied to the related art;
FIG. 13 is a typical illustration showing an example in which the present invention is applied to the related art;
FIG. 14 is a typical illustration showing an example in which the present invention is applied to the related art;
FIG. 15 is a typical illustration showing an example in which an intersection of the scan lines within the human body is varied in a scan direction and a depth direction;
FIG. 16 is a typical illustration showing an example in which an intersection of the scan lines within the human body is varied in a scan direction and a depth direction;
FIG. 17 is a typical illustration showing an example in which an intersection of the scan lines within the human body is varied in a scan direction and a depth direction;
FIG. 18 is an illustration showing the first example in which information as to the depth direction is displayed;
FIG. 19 is an illustration showing an example in which coordinates of a tomographic image according to the conventional sector scan is displayed along with a tomographic image according to the present invention;
FIG. 20 is an illustration showing an example in which an image interpolation is effected;
FIG. 21 is an illustration showing an example in which an image interpolation is effected;
FIG. 22 is an illustration showing an example as to an image display according to the present invention;
FIG. 23 is a schematic diagram showing a functional structure of an ultrasonic diagnostic apparatus.
FIG. 24 is a typical illustration of an example showing a relationship between an arrangement of the piezoelectric transducers and reflecting points of ultrasonic waves within the subject;
FIG. 25 is an illustration showing a pattern of weighting for the respective received signals derived through the elements;
FIG. 26 is an illustration showing an example in which a size of the receiving aperture is varied in a state that weighting is fixed;
FIG. 27 is a typical illustration showing the state of transmitting and receiving of the ultrasonic waves through rib-to-rib toward the heart using the conventional electronic sector scheme of ultrasonic diagnostic apparatus;
FIG. 28 is a typical illustration showing a technique of removing or reducing a bad influence of the ribs, which has been proposed in the related art;
FIG. 29 is a typical illustration useful for understanding the proposal according to the related art; and
FIG. 30 is a typical illustration useful for understanding the proposal according to the related art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, there will be described embodiments of the present invention.
FIGS. 1 to 4 are each a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the first ultrasonic diagnostic apparatus of the present invention.
According to the present embodiment, it is assumed that 64 pieces of element are arranged with 0.3 mm of element pitch, and thus there is provided 19.2 mm of aperture. Transmitting and receiving are effected using a number of elements, such as the maximum 48 pieces of element for transmitting and the maximum 64 pieces of element or overall elements for receiving, as much as possible, and setting up a cross point 2 of the respective scan lines at about 5 mm of depth.
First, FIG. 1 concerns an example in which the leftmost scan line is formed.
A starting point 3 of the scan line is set up at a position shifting from the center 1 to the right side by the corresponding 17 pieces of element (about 5 mm), and the ultrasound beam is transmitted from the starting point 3 toward the left down. In this case, since 15 pieces of element remain on the right of the starting point 3, the number of elements available for transmission is 30 pieces (aperture 4) which is a maximum assuming symmetry with respect to right and left. For receiving, the same elements as transmission are used. With respect to weighting for receiving, as shown in a mountain-shaped weighting distribution 5 in the figure, the higher weighting is provided at the central part with the starting point 3 in the center, and the lower at the edge parts.
Next, there will be described a case in which the scan line of the central part as shown in FIG. 2 is formed. In FIG. 2 and the following figures, suffixes "T" and "R" of reference numbers denote transmitting end and receiving end, respectively. For example, in FIG. 2, 4T and 4R denote a transmitting aperture and a receiving aperture, respectively.
The scan line shown in FIG. 2 concerns an example in which the starting point 3 is shifted to the left side by the corresponding 2 pieces of element. While the number of elements available for transmission is 60 pieces which is a maximum assuming symmetry with respect to right and left, the maximum number of elements available for transmission is set up to be 48 pieces, and thus 48 pieces of element are used for transmission. With respect to receiving, in a similar fashion to that of FIG. 1, the receiving is implemented using 60 pieces of element the number of which is a maximum assuming symmetry with respect to right and left with the starting point 3 in the center.
Performing the transmitting and receiving scans as shown in FIGS. 1 and 2 provides, as shown in FIG. 3, a sector configuration of scan with a cross point 2 within the human body in the center. FIG. 4 shows a distribution of the number of elements for transmitting and receiving to the shift of scan lines. Incidentally, if intensity of the received signal of the scan line on the edge portion is insufficient owing to shortage of the elements, it is possible to facilitate an observation by increasing an amplification factor of the scan line on the edge portion.
FIGS. 5-8 are each a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the second ultrasonic diagnostic apparatus of the present invention;
According to the present embodiment, as to an arrangement involved in receiving, that in the embodiment shown in FIGS. 1-4 is retained without any changes, and as to an arrangement involved in transmitting, there is so arranged that the respective scan lines on the transmitting side intersect at a position 2T of about 2.4 mm in depth which is shallower than that in the embodiment shown in FIGS. 1-4. The reason why according to the present embodiment there is so arranged that the respective scan lines on the transmitting side intersect at the position which is shallower than that in the embodiment shown in FIGS. 1-4 is that such an arrangement permits the situation that a shift amount 6T (cf. FIG. 7) of the center 3T for transmitting is less than a shift amount 6R of the center 3R for receiving. Consequently, it is sufficient for forming the edge portion scan lines to simply shift the starting point 3T from the center by the corresponding 8 elements, so that the number of elements available for transmission is 48 pieces which is a maximum assuming symmetry with respect to right and left. Thus, as shown in FIG. 8, it is possible to transmit overall scan lines using 48 elements the number of which is a maximum number of elements available for transmission. Therefore, comparing with the embodiment shown in FIGS. 2-4, while it is influenced somewhat by the ribs, it is possible to enhance resolution of the edge portions and intensity of the received signals by the corresponding enlargement of the transmitting aperture.
FIGS. 9-11 are each a typical illustration of ultrasonic wave transmitting and receiving according to an embodiment of the third ultrasonic diagnostic apparatus of the present invention;
according to the present embodiment, as to transmitting, in a similar fashion of that of the conventional electronic sector system (cf. FIG. 27), the ultrasonic waves are transmitted with the central part 1 of the elements 12 in the center, and with respect to receiving only, this is the similar as to the matter of the embodiment shown in FIGS. 1-4 and the embodiment shown in FIGS. 5-8. As seen from FIG. 9, when the ultrasound beams are transmitted toward the left side, the left half of elements among the elements 12 receive reflecting echoes from the ribs more than that of the right half of elements. Hence, as shown in FIG. 10, only the elements of the right-hand side among the elements 12, which will receive less reflecting echoes from the ribs, are used for receiving, thereby contributing to reduction of the reflecting signals from the ribs.
FIGS. 12-14 are each a typical illustration showing an example in which the present invention is applied to the techniques (cf. FIGS. 29 and 30) proposed in Japanese Patent Publication No. 12971/1992. According to this scheme, the number of elements for transmitting and receiving is increased in comparison with the conventional scheme, thereby improving resolution and intensity of the received signals. With respect to the scan lines of the central part of the sector configuration, the number of elements for transmitting and receiving is increased in comparison with that of the edge portions, thereby improving remarkably a portion of the scanlines of the central part of the sector shaped tomographic image in the quality of image.
FIGS. 15-17 are each a typical illustration showing an example in which an intersection of the scan lines within the human body is varied in a scan direction and a depth direction.
Since a distance from a body surface up to the ribs and an interval between adjacent ribs differ from individual to individual, it is desirable to provide, as shown in FIGS. 15 and 16, such an arrangement that a position 2 of the sector center is optionally variable in depth directions 21 and 22. Providing a variable amount of 1-6 mm in depth permits the system to be sufficiently applicable for children to adults who are on the plump side with a distance between the body surface and the ribs in the order of 8 mm. It is acceptable to mount, for example, a variable switch on a scan panel so as to control the variable amount while observing an image.
Further, if it is so arranged that the sector center 1 is optionally variable also with respect to a scan direction (right and left direction in FIGS. 15-17), then for example, in a case where a target is in the left edge portion of the screen, it is possible, as shown in FIG. 17, to shift a group of elements to the right so that the sector center can be moved to the left-hand side 23. In this manner, the number of elements for transmitting and receiving on the right-hand side is increased. An increase of the number of elements for transmitting and receiving on the right-hand side makes it possible to enhance resolution of the left-hand side portion of the image and intensity of the received signal, thereby enhancing a quality of image on the portion of the left-hand side.
As another embodiment, not illustrated, it is acceptable to provide on an operation panel a switch for change-over of a sector mode so as to be switched also to the conventional sector scan (cf. FIG. 27). Providing an additional function of change-over of a sector mode permits the system of the invention to be used for a case other than the case of diagnostic of the heart through an opening between adjacent ribs.
Incidentally, according to the system of the present invention, the number of elements for transmitting is reduced with nearer scan lines to the edge portions larger in an amount of shift of the center 2 of a group of elements for transmitting and receiving. This will invite a lower transmitting sound pressure on the edge portion. Further, since the number of elements for receiving is also reduced, intensity of the received signal is reduced. This will invite darkness on the edge portions when displayed in the form of image, and thus be in danger of assuming image hard to see. For these reasons, according to the present invention, there is provided an additional function in which a drive voltage increases with nearer scan lines to the edge portions to enhance the transmitting sound pressure, thereby improving an S/N ratio. Further, if there is provided a function in which an amplification factor is enhanced with nearer scan lines to the edge portions, it is possible to prevent the edge portions from being displayed with dark images, thereby assuming images easy to see.
Next, there will be described an example involved in an image display.
FIG. 18 is an illustration showing the first example in which information as to the depth direction is displayed.
When the sector center according to the present invention is set up within the human body (between adjacent ribs) and is varied optionally, if a tomographic image 31 of only a portion deeper than the sector center is displayed in a similar fashion to that of the conventional sector scan, there is the possibility that the position of the depth direction can not be grasped. For this reason, there is displayed also a tomographic image 30 from a surface of the elements to the sector center, thereby facilitating understanding a relative position relation of the elements and the tomographic image. As another method, instead of no display of the tomographic image 30 shown in FIG. 18, it is acceptable to display information as to a distance from the surface of the elements on a scale basis, or to display a position of the surface of the elements. Further, as shown in FIG. 19, if there are displayed coordinates provided by a sector display from the center 1 of the elements along with a tomographic image 31 according to the present invention, it will be easy to use for an operator who is used to the conventional display scheme for the tomographic image and an operator who uses the sector scan according to the present invention and the sector scan according to the conventional scheme on a switching basis, since there is no remarkable changes on the screen.
FIGS. 20 and 21 are each an illustration showing an example in which an image interpolation is effected.
FIG. 20 illustrates an example in which an image interpolation is effected in a remaining area 32 other than a display area of the tomographic image 31 according to the present invention, in the conventional sector scan in FIG. 19. As an example of an image to be interpolated, there are considered a tomographic image formed through the conventional sector scan taking with the sector center 1 in the center of the sector configuration, or a uniform brightness of image and the like. Further, according to an example shown in FIG. 21, as an interpolating image, there is used an image in a case where a trapezoid scan is effected with a shift width 6 (cf. FIG. 3) of the starting point 3 (cf. FIG. 1) of the scan lines as an aperture.
FIG. 22 is an illustration showing the fourth example as to an image display according to the present invention.
According to the present invention, the ultrasonic waves are transmitted and received avoiding the ribs, and thus the field of the vision is narrowed by the corresponding area 32 portion in comparison with the conventional sector scan. For this reason, according to the present embodiment, a scan angle is spread exceeding 90°, so that a deep portion can be seen over the wide range. According to the conventional scan scheme in which a scan is performed in a sector configuration from the center 1 of the elements, even if the scan angle is spread, the ultrasonic waves will be obstructed by the ribs. And thus, it is difficult to expect the effect. On the contrary, the scan scheme according to the present invention makes it possible to see the deep portion over the wide range.
While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by those embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. | There is provided an ultrasonic diagnostic apparatus in which a plurality of piezoelectric transducers are arranged in a predetermined direction so as to transmit and receive ultrasonic waves to obtain a tomographic image on the inside of the subject. The ultrasonic diagnostic apparatus adopts such a scheme that a sector scan is electronically performed, and is capable of preventing deterioration of an image by reducing an influence of reflection of the ultrasonic waves from the ribs, and forming a good image improved in resolution. An intersection of scan lines at at least receiving end is set up between rib-to-rib which are located at the position deeper than the body surface of the subject. An aperture for transmitting and receiving of ultrasonic waves along the scan line of the central part of the sector configuration is wider than that along the scan line of the edge portion of the sector configuration. | 0 |
This is a continuation of application Ser. No. 07/608,812, filed Nov. 5, 1990, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a method and an apparatus for a vehicle to get traffic information and using the information to navigate. The characteristic of this invention is that a vehicle acquires the information of traffic status in front of it by means of information transference from the passing vehicles.
Some of the prior vehicle navigation systems, presently available or under development, use satellites which allow the vehicles to identify their present location, while they do not provide traffic information. Other navigation systems, using a central computer to provide traffic information for vehicles, communicate with the vehicles through signal posts allocated along the roads. Because these systems have to build transceiver posts at many adequate locations (such as each intersection), the vehicles that are not at the fight location (such as while blocked between the intersections) can not receive the information, such systems work well only in an urban area with light traffic conditions.
The U.S. Pat. Nos. 4,513,377 of Hasebe et al.; 4,963,865 of Ichikawa et al. and 5,016,007 of Iihoshi et al. disclose display systems which can display the present position of the vehicle relative to a map on a display screen through map-matching calculations. But these systems provide only static information about the path instead of dynamic conditions of the traffic.
In the U.S. Pat. No. 4,706,086, a system for communication and signalling between a plurality of vehicles is disclosed. Each vehicle is equipped with signal receiver means, transmitter means, detectors means and a control unit. It allows the driver of the vehicle to be provided with information about the travelling conditions (tailbacks, forced stops, "road clear", fog bands, rain etc.) on the stretch of road on which he is about to travel. However, the information is only about the condition of the road straight ahead. It is not concerned with traffic problems that might be encountered when travelling over a network of interconnected roads to a particular destination.
SUMMARY OF THE INVENTION
This invention, in order to solve the problems mentioned above, provides a method and an apparatus for transference of traffic information among vehicles to facilitate navigation of those vehicles. The system of this invention does not require any central computer, satellites or roadside posts.
This invention equips a vehicle with an apparatus to record traffic information such as the driving speed and the path, to send the information to other passing vehicles through a transceiver, and to receive the information from those passing vehicles. It enables the vehicles equipped with this apparatus to collect and interchange traffic information during passing, and to achieve navigation by incorporating map data and traffic information.
The composition and function of this invention will be expressed in company with the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example of the invented method in which the traffic information of a first vehicle is transferred via a second vehicle to a third vehicle.
FIG. 2 shows another example of the invented method in which the traffic information of one vehicle is transferred to another vehicle via two other vehicles.
FIG. 3 shows a block diagram of an embodiment of the invented apparatus.
FIG. 4 shows the outward appearance of an indicator and a microcomputer of an embodiment of this invention.
FIG. 5 shows a functional diagram of a navigation unit in an embodiment of this invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As FIG. 1 shows, three vehicles a 1 , a 2 , and b equipped with the invented apparatus, said vehicles being driven individually along two opposite paths X and Y in two adjacent roads A and B. The vehicle a 1 in the front on road A sends its traffic information, such as the driving path and speed, to the passing-by vehicle b at a position P 1 . When the vehicle b passes on the vehicle a 2 in the rear of the road A at a position P 2 later, the traffic information of the vehicle a1 will then be sent to the vehicle a 2 by the vehicle b. As a result, the vehicle a 2 obtains the traffic status (e.g. the average driving speed of a certain path) in front according to the information it gets. Vehicle a 2 becomes a navigatable vehicle because it utilizes the traffic information for navigation purposes.
The procedure mentioned above shows how a vehicle can send information to another following vehicle behind at a distance through the medium of a vehicle on the adjacent path. In the same way, the vehicle b sends its traffic information to any vehicle behind it (not shown in the figure) through the medium of the vehicles a 1 , a 2 on the adjacent road A. In other words, a vehicle with the invented apparatus collects not only the traffic information of its own but also that of other vehicles.
In practice, the distance of information transference among the passing-by vehicles (usually the vehicles are in a two-way road, cross roads, or forks of a road) is within a limited range, such as 200 meters, when the vehicles are driving close. And, a vehicle which is closely behind a vehicle up front need not receive the information about the lead vehicle because the traffic status is visible. Therefore, a low power electromagnetic wave, infrared ray or laser transceiver that points to a certain direction (for the communication of two passing vehicles only) or functions in a specific range (such as only receives signals from other vehicles within the range of 135 degrees to the fight and left sides of the driving direction) can be used.
FIG. 2 shows an example of the vehicles transferring their traffic information successively. A navigatable vehicle f acquires the traffic information of a vehicle c through the help of relay vehicles d and e. The vehicle c driving along a path C x sends its traffic information to the passing-by vehicle d in a position X 1 . Later, the vehicle d driving along paths D 1 , D 2 and D 3 sends its traffic information to a passing vehicle e driving along paths E 1 and E 2 . Then the traffic information of the vehicle c carried by the vehicle e will be relayed to the passing-by vehicle f in a position X 3 . That is, the navigatable vehicle f along a path F will acquire the traffic status information of the front path C x .
The content and the process of transference of traffic information are described as follows.
The vehicle is equipped with an electronic map device which can display digitized road map information and identification of the position of the vehicle on the map. (The vehicle may have a direction sensor and a displacement sensor to record the movement of the vehicle. The movement data combined with the starting position once set by the driver can be applied to map the locus of the vehicle to the map utilizing a prior technology.) Based on the technology, the roads on the map are constructed by straight or curved lines linking various points. (A two way or a one way road can be represented by its center line. Taking FIG. 2 as an example, the cross point N 2 , the turning points N 1 and N 3 of the center lines are representative points of the roads.) All these points can be identified through their absolute coordinates (geological coordinates). Thus, the vehicle can be matched to the map by comparing its movement to the coordinates. For example, when the vehicle d in the path D 1 turns into the path D 2 , the turning position will be mapped to the point N 1 . (The sensed displacement of the vehicle will be revised if it differs from the map.) Also, the driving path D 2 of the vehicle d can be identified by the link of the points N 1 and N 2 . For example, a vehicle drives through points N 1 , N 2 and N 3 , its traffic information can be described as follows:
<. . . , coordinates of N 1 , average driving speed, the longest halting time, coordinates of N 2 , average driving speed, the longest halting time, coordinates of N 3 , . . . >
Wherein, the average driving speed is the value of the mileage between two points divided by the driving time and it enables the apparatus to conjecture the traffic status whether in heavy traffic or not. The longest halting time is the longest time for a vehicle in the path while staying in an idle speed because of some reasons (such as encountering the red lights) which enables the apparatus to estimate the changing cycle of the traffic lights in the city. The process and usage will be described later. To receive and transmit the traffic information, the vehicle can be equipped with a signal transceiver using known technologies of infrared rays, laser or radio, or it can be adapted to a mobile phone with multiplexer. These are prior arts which need not to be described in detail.
The traffic information transferred among the vehicles includes the traffic information of the vehicle itself as well as of other vehicles. An example of the format of the transference is set as follows:
<starting code, code of the vehicle itself, traffic information about the vehicle itself; code of another vehicle 1, traffic information of the vehicle 1 itself; code of the other vehicle 2, traffic information of the vehicle 2 itself; . . . ; code of another vehicle n, self-traffic information of the vehicle n, ending code.>
The starting code and the ending code are set for the vehicle that receives the information (which will be mentioned as receiving vehicle hereafter) to identify the signal range. For the purpose of classifying and identifying the information, the codes of the vehicles can he the license numbers or other identification numbers. The vehicles 1 to n are those in front of the receiving vehicle. The traffic information about vehicles 1 to n was previously gotten from adjacent passing vehicles, temporarily stored and later transferred to the receiving vehicle. Any outdated information, such as the routes that the receiving vehicle has already passed, will be removed.
FIG. 3 shows the composition of an embodiment of the present invention. The main part is a microcomputer 1, including a self-position identifier 11 which receives the detected value of the above mentioned displacement sensor 2, direction sensor 3 and the map data 12 to identify the position of the vehicle. The position of the vehicle itself can be estimated by comparing the detected value with the map data 12. The differential, if any, will be revised when the vehicle changes its direction. The revision will be the reference for the following comparison. If the differential is beyond a certain range, which means there is a route not provided by the map data 12, then it can be ascertained by the driver and stored into the map. The driver, in a vehicle on a straight road for over a certain mileage, will be reminded by the apparatus to ascertain the position of the car by punching a button to clear any differential when he arrives at an evident position (such as a cross road). The traffic information of the vehicle itself is stored in a self-information register 13. The information in the register 13 can be processed by an output-information encoder 17 and sent out by a transmitter 7 as the first information of each transference as mentioned above. On the other hand, the traffic information from other vehicles is received by a receiver 4 and decoded by a decoder 14. Each first traffic information (of the vehicle itself that sends it out) will be stored in a passing-by-vehicle information register 16 and is provided to the encoder 17 and the transmitter 7 to send out. The storage in the register 16 is updated in a process of first-in & first-out and removing any information of the path already behind the receiving vehicle. The rest of the received traffic information (other than the self information of the vehicle that sends it out), i.e., information of the vehicles in front of the receiving vehicle, will be received and stored in a front-vehicle information register 15. To avoid accumulating repeated information, the information is stored based on the codes of the vehicles and is continuously updated. A navigation unit 18 fetches the data from the self-position identifier 11 and from the register 15, generates navigation information and sends it to an indicator 8. The composition and the operation of the navigation unit 18 and the indicator 8 will be described below.
FIG. 4 shows the outward appearance of an indicator and a microcomputer in an embodiment of this invention. The indicator 8 includes a liquid crystal display or a screen 81 to indicate the map and other navigation information. It can also be equipped with pilot lights 82 and a beeper or speaker 83 to provide warning sounds. The map data 12 can be stored in a compact disc (CD) and retrieved by a player 120 as shown, or a memory device (such as DRAM or SRAM) accessed by the microcomputer 1. It includes not only the road position information, road width, shape of intersections, but also the region names, road names, starting and ending numbers of the residence, driving limits (one-way street, speed limitation, etc.), and locations (including addresses and telephone numbers) of gas stations along the roadsides, restaurants and hotels, service stations, rest stations, offices, stores, and so on. The microcomputer 1 provides suitable user interfaces, such as a keyboard 10 as shown or screen-touch or verbal input units, to input commands or data--such as to contract or enlarge the map, to identify the position of the vehicle, to input the destination, etc. The composition of the navigation unit 18 set in the microcomputer 1 will be described by referring to FIG. 5.
FIG. 5 shows the content and function of the navigation unit 18 which mainly comprises a map-drawing module 181 and a navigation module 182. The map-drawing module 181 generates the map and displays it with the indicator 8 (on the screen 81 shown in FIG. 4) based on information 110 of the position and direction of the vehicle (identified by the self-position identifier 11 shown in FIG. 3) and the related map data 12. The map is displayed in two modes--the geological direction (north-up) and the vehicle direction (heading-up). For instance, when the position of the vehicle itself and the destination are not identified yet, the map is north-up and controlled by the user through interfaces (such as the keyboard 10 in FIG. 4) to move upward, downward, left and fight. When the vehicle is moving, the map is heading-up, i.e. the vehicle itself is stationary in the middle but a little bit low on the display, and the map is moving and rotating accordingly. The size (displayed area) of the map is adjustable, for example, from 0.5*0.5 km, 3*3 km, 15*15 km, 100*100 km to 600*600 km, by the user's command or automatically by the apparatus based on the relationship between the position of the vehicle and the destination--when the destination is just identified, a map in a suitable scale that covers the vehicle location and the destination will be shown. When the vehicle is driving, the size of the map can be contracted to a smaller area (such as 3*3 km); and when closing to the destination, it can be contracted to the smallest area to reveal the detail. The scope for revealing the detail is related to the size and contains only the needed information for guiding the vehicle to the destination, therefore, unnecessary details are omitted in a larger size of map.
The navigation module 182 provides functions of path indication, driving forecast and speed-control instruction. This module, after identifying the present position of the vehicle and its destination, searches for all the available paths based on road information 121 (the speed limit, allowed directions, etc., which are pans of the map data 12) and front-vehicle information 151 (such as the average driving speed stored in the front-vehicle information register 15 as shown in FIG. 3). The module calculates the driving times for all the available routes respectively, and constructs several better time-saving routes displayed on the map for reference. The routes appear either orderly by the users command, or simultaneously in bold-medium-thin line or real-dotted line formats. The module 182 also provides a gas-efficient selection by calculating the respective gas consumption for each path by multiplying its distance into the vehicle's gas consumption rate corresponding to the average driving speed. The result, depending on the user's selection through key punching, can be constructed into several displays based on gas consumption or time spent. The whole system, switched on, will continuously receive traffic information sent by the passing vehicles and update the information 151; therefore, it may refresh aforesaid better route displays at intervals, such as every 10 seconds. The already-passed route can be indicated by a flashing line. Also, the name of the passing roads and the cross roads in front should be timely updated with clear indication on the map. At a suitable time margin (depending on the driving speed) before the vehicle turns in another direction, the module 182 will alert the indicator 8 (with sound or light signal as warnings) to remind the driver to keep to the fight or left lane, and display the distance before making the turn. The indicator 8 can also display the mileage still left, the estimated arrival-time, the still-needed amount of fuel, etc., depending on the driver's command. If the fuel is not sufficient, the indicator 8 will remind the driver and display the nearest gas station and navigate. When the destination is near (for example, within 5 km), the display will start counting down the time left and mileage. The system can also suggest the cruising speed based on the traffic condition and the speed limit of each route and the desired arrival time input by the driver. On the route with frequent stops due to traffic lights, the module 182 will estimate the light changing cycle by checking the most frequent longest halting time among those of the front vehicles in the information 151, and further estimate the light changing time based on the position of the vehicle and its driving status, and then informs the driver to adjust the speed to minimize stopping, and reminds (by displaying the elapsed time) the driver to start up in time upon the light changing.
A statistic module 183, according to the user's command when he arrives in the destination, will compute and display, based on the self-vehicle information 131, the total driving time, mileage, average of driving speed, number of stops, time for stops, number of turns, and number of on-coming vehicles that it has met.
The above embodiment explains the traffic information passing among the vehicles and the possible ways to use it. In practice, the traffic information can also be received through a receiving station, similar to the central computer system and transceiver posts mentioned before, then it is processed to generate required information, including the positions of every vehicle, traffic regulations, record of collecting tolls, query for those who need it, and so on. The traffic information can also offer navigation data to those vehicles only equipped with receivers. These applications are also included in the | A method and an apparatus for the transference of traffic information among vehicles and for assisting navigating the vehicles. The traffic information of the vehicles, such as the speed and the route and direction, is remotely transmitted to each other during passing, via communication devices mounted on each of the vehicles. The apparatus comprises sensors to detect the direction and the displacement of the vehicle; a microcomputer to recognize the position of the vehicle by referring the detected direction and displacement to a digitized map; a receiver to receive the passing vehicle's traffic information to be processed by the microcomputer; a transmitter to transmit the traffic information to the passing vehicle; and a navigation unit in the microcomputer to generate navigation information and indicate the traffic information of vehicles ahead is transmitted to a receiving vehicle in an indirect manner via a passing vehicle. | 6 |
RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 61/309,051, which was filed Mar. 1, 2010.
BACKGROUND
[0002] As natural resources, particularly those required for heating and cooling, become scarcer, consumers and businesses are trying to utilize better technologies to lower the cost of energy and the like. Likewise, local governments and industry groups are promulgating new standards for energy compliance.
[0003] For instance, ASHRAE (The American Society of Heating, Refrigerating and Air Conditioning Engineers), has promulgated standards that will require that new conditioned air low-rise commercial construction will require roof u-values of between 0.035-0.040 and wall u-values of 0.050-0.060. This is a significant change from its current u-value of 0.062 for the roof.
SUMMARY
[0004] According to an embodiment shown herein, a method for installing a vapor barrier in a building includes loosely hanging a strip around a periphery of an area to be insulated, providing a vapor barrier having a plurality of attachments, the attachments adapted to attach to the strip, attaching the strip attachments to the strip, and then tightening the strip to tighten the vapor barrier.
[0005] According to a further embodiment shown herein, a method for installing insulation in a building includes loosely hanging a strip around a periphery of an area to be insulated, providing a web having a plurality of attachments, the attachments adapted to attach to the strip, attaching the strip attachments to the strip, and tightening the strip.
[0006] According to a further embodiment shown herein, a method for installing a vapor barrier in a building includes attaching hangers for holding a strip at corners between supporting members of the building, loosely hanging a strip on the hangers, providing a vapor barrier having a plurality of attachments, the attachments adapted to attach to the strip, attaching the attachments to the strip, and tightening the strip.
[0007] According to a still further embodiment shown herein, an apparatus for hanging a vapor barrier in a building has a strip for attaching around a periphery of an area to be insulated, the strip being capable of being tightened, and a vapor barrier having a plurality of attachments attached to the vapor barrier away from an edge thereof to create an area of the vapor barrier, the attachments adapted to attach to the strip and the area being adaptable to attach to the building.
[0008] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partial perspective view of a typical low-bay building construction.
[0010] FIG. 2 is a perspective view of a vapor barrier for use in the low-bay building of FIG. 1 .
[0011] FIG. 2A is an alternative embodiment for the area shown as 2 A in FIG. 2 .
[0012] FIG. 3 is a perspective view of a low-bay building having a plurality of attachments and a wire.
[0013] FIG. 4 is a top perspective view of the vapor barrier of FIG. 2 attached to the building of FIG. 3 .
[0014] FIG. 5 is a perspective view of a tool for use with the wire used in FIG. 4 .
[0015] FIG. 6 is a method of using an embodiment shown in the other Figures herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] FIG. 1 shows a typical low-rise building 10 having a plurality of posts 15 supporting a plurality of beams 20 that support a plurality of purlins 25 . The posts also support a plurality of eave struts 30 . The purlins are shown having a capital “Z” like shape but other shapes are contemplated. The posts 15 , purlins 25 , eave struts 30 and beams 20 are constructed of steel but other materials are also contemplated herein.
[0017] Referring now to FIG. 2 , a vapor bather 35 for use in the building of FIG. 1 or the like is shown. The vapor barrier 35 , which is typically a web of impervious fabric material, like a coated plastic, has a plurality of attachments such as hooks 40 sewn into the vapor barrier thereof (though other means of attaching the hooks to the vapor bather are contemplated). The hooks should be about 9-24 inches apart though other distances are contemplated. The hooks 40 are not at the edge 45 of the vapor barrier but are designed to attach to a flexible strip such as a wire, cord or cable 50 inside the edge 45 . The material of the vapor barrier (shown as length A and B in FIG. 2 ) closer to the edge 45 is used to seal the vapor bather against the building 10 (see edge 45 in phantom if FIG. 4 ).
[0018] Referring to FIG. 2A , an alternative way of attaching the hooks 40 includes folding over the edges 45 of the vapor barrier 35 to create a double layer 51 of vapor barrier for strength. A rivet 53 is placed through a hole 52 in the hook 40 and the doubled vapor bather 51 to secure the hook to the vapor barrier.
[0019] Referring now to FIG. 3 , a hanger such as eye hooks 55 are attached to the beams 20 and the purlins 25 at least every 20 feet or so. It is also preferred that the eye hooks 55 are placed at the corners of the eave struts 30 and the purlins 20 to define a bay to be insulated. Though eye hooks are preferred because the wire or cable 50 is attached through the eyes hooks 55 and left slack, at least at first, other attachment methods are contemplated that will hold the wire and allow it to be tightened. The wire shown is one-eight inch cable though other materials are contemplated as mentioned hereinabove. The eye hooks 55 may also be placed against the beams 20 if more insulation is desired.
[0020] Referring now to FIG. 4 , to attach the vapor barrier 35 to the wire 50 , one side of the vapor barrier is secured to the wire 50 along a beam by attaching the hooks 40 in the vapor barrier along a beam to the wire 50 . Then an end of the vapor barrier is secured, by attaching the hooks 40 to the wire 50 along an eave strut 30 . Then the other side of the vapor barrier 35 is secured to the wire 50 attached to another purlin by attaching the hooks in the vapor barrier along the wire 50 on the other purlin 25 . Then the other end of the vapor barrier 35 is secured, by attaching the hooks 40 to the wire 50 along the other eave strut 30 .
[0021] Once both sides are installed and the vapor barrier 35 is square, the wire 50 , which is loosely attached to itself at both ends 60 is tightened (see FIG. 5 ). The cable may be tightened with pliers 65 or come-alongs and secured by a Gripple® fastener (Gripple is a registered trademark of the Gripple Limited Corporation of East Sheffield, England) or the like (not shown) and secured together so that the tightened cables do not slip. Tightening the cable causes the cable to pull the hooks, and the vapor barrier thereby, towards the edges of the area to be insulated between the purlins 25 and the edge struts 30 thereby tightening the vapor bather 35 left to right and front to back. The vapor barrier 35 may now support insulation 70 .
[0022] With the vapor bather 35 tight in place, the vapor bather 35 defined by areas A and B in FIG. 2 is placed against the beams, around the purlins and eave struts by means of adhesive or the like to create tight vapor seal.
[0023] Once the vapor barrier 35 is installed, insulation 70 is then unrolled into place from the top side of the building onto the vapor bather between the purlins 25 . Because the depth of installation is dependent on where the eyehooks 55 are placed, the vapor barrier and the insulation placed atop the vapor barrier can be placed virtually anywhere below the purlins so that the purlins do not compress or interfere with the insulation and the required R-values. The eye hooks 55 can be lowered should the building owner ever require more insulation be added to the building.
[0024] Referring to FIG. 6 , operation of the embodiments shown is shown. Hanger such as eye hooks 55 are attached to the eave struts 30 and the purlins 25 (step 100 ). Attachments such as hooks 40 are attached to the vapor barrier 35 (step 105 ). A strip such as wire 50 is hung from the hangers/eye hooks 55 (step 110 ) and the attachments/hooks 55 are attached to the strip/wire 50 (step 115 ). Insulation 70 is disposed between the purlins 25 (step 120 ) and the strip/wire 50 is tightened to remove the slack therein (step 125 ). If more insulation 70 is needed, the hangers/eye hooks 55 are attached to beams 20 (step 130 ) and the strip/wire 50 is then suspended from the hangers/eye hooks 55 and eave struts 30 (step 135 ). The attachments/hooks 55 are attached to the strip/wire 50 (step 140 ). More insulation 70 may be disposed between and/or below the purlins 25 (step 145 ) and the strip/wire 50 is tightened to remove the slack therein (step 150 ).
[0025] One of ordinary skill in the art will recognize that if a vapor barrier is not necessary, a web or other type of support may be used to hold the insulation in place.
[0026] Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
[0027] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims. | A method for installing a vapor bather in a building includes loosely hanging a strip around a periphery of an area to be insulated, providing a vapor bather having a plurality of attachments, the attachments adapted to attach to the strip, attaching the attachments to the strip, and then tightening the strip to tighten the vapor bather. | 4 |
FIELD OF THE INVENTION
The present invention relates to communication systems, and in particular, to signal message compression within communication sessions handling SIP messages.
DESCRIPTION OF THE RELATED ART
A communication system can be seen as a facility that enables communication sessions between two or more entities such as user equipment and/or other nodes associated with the communication system. The communication may comprise, for example, communication of voice, data, multimedia and so on. A user equipment may, for example, be provided with a two-way telephone call or multi-way conference call. A user equipment may also be provided with a connection to an application providing entity, for example to an application server (AS), thus enabling use of services provided by the application server.
A communication system typically operates in accordance with a given standard or specification which sets out what the various entities associated with the communication system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment is provided with a circuit switched service and/or a packet switched service. Communication protocols and/or parameters which shall be used for the connection may also be defined. In other words, a specific set of “rules” on which the communication can be based on needs to be defined to enable communication by means of the system.
Communication systems providing wireless communication for user equipment are known. An example of the wireless systems is the public land mobile network (PLMN). Another example is a mobile communication system that is based, at least partially, on the use of communication satellites. Wireless communications may also be provided by means of other arrangements, such as by means of wireless local area networks (WLAN). Communication on the wireless interface between the user equipment and the elements of the communication network can be based on an appropriate communication protocol. The operation of the station apparatus of the communication system and other apparatus required for the communication can be controlled by one or several control entities. The various control entities may be interconnected. One or more gateway nodes may also be provided for connecting a communication network to other networks. For example, a mobile network may be connected to communication networks such as an IP (Internet Protocol) and/or other packet switched data networks.
An example of the services that may be offered for users of a communication system is the so called multimedia service. An example of a communication system enabled to offer multimedia services is the Internet Protocol (IP) Multimedia network. IP Multimedia (IM) functionalities can be provided by means of a IP Multimedia Core Network (CN) subsystem, or briefly IP Multimedia subsystem (IMS). The IMS includes various network entities for the provision of the multimedia services.
The Third Generation Partnership Project (3GPP) has defined use of the General Packet Radio Service (GPRS) as a backbone communication system for the provision of the IMS services, the GPRS being given herein as a non-limiting example of a possible backbone communication system enabling the multimedia services. The Third Generation Partnership Project (3GPP) has also defined a reference architecture for the third generation (3G) core network which will provide the users of user equipment with access to the multimedia services. This core network is divided into three principal domains. These are the Circuit Switched (CS) domain, the Packet Switched (PS) domain and the Internet Protocol Multimedia (IM) domain.
The latter of these, the IM domain, is for ensuring that multimedia services are adequately managed. The 3G IM domain supports the Session Initiation Protocol (SIP) as developed by the Internet Engineering Task Force (IETF). Session Initiation Protocol (SIP) is an application-layer control protocol for creating, modifying and terminating sessions with one or more participants (endpoints).
Before a user equipment is able to communicate with an IM CN subsystem, a GPRS attach procedure must be performed and a communication channel known as Packet Data Protocol (PDP) context for SIP signalling must be established.
With low-rate IP connectivity, transmission delays are significant. Call setup and feature invocation are adversely affected by retransmissions and multiple messaging, as required in some flows. SigComp protocols provide a solution to this problem by offering robust, loss-less compression of application messages. Due to the heavy signaling involved and SIP, being a text based protocol, 3GPP IMS Release 5 standards mandates SigComp (Signaling Compression).
Once a device is in receipt of a SigComp compressed message or a message to compress a uncompressed message using the SigComp protocols, the device provides a virtual machine (UDVM) with limited resources for compressing/decompressing the message.
The virtual machine is quite limited in its capabilities. For example the memory usable by the virtual machine is limited to the receive buffer used by the decompressing/compressing endpoint. The total amount of memory allocated for the receive buffer and virtual machine is typically only a few kilobytes. This is because for SIP endpoints the default decompression memory size (dms) is 8 kilobytes, therefore in the virtual machine for compression and decompression both instructions and data must fit within this limited space. The virtual machine program is allowed simple I/O operations: it can input data from the compressed message, it can output decompressed data, and it can create, access and free state items. State items are items stored within the virtual machine memory from previously received messages.
The memory used by a UDVM is typically 4 kilobytes or less. Part of it is consumed by bytecode and its variables. Typically, there is only 3.5 kilobytes or less available for the ring buffer and other data structures storing the received compressed message, the processed decompressed message and any further dictionaries. When compressing longer messages, it is not possible to keep known static (3468 or 4836 bytes depending on algorithm) and dynamic dictionaries as well as complete compressed message completely in the memory.
The UDVM is active only when the protocol message is received. After receiving a SigComp message, the endpoint invokes the UDVM. For example in decompression the UDVM executes the bytecode or instructions to perform the decompression steps until the message has been completely decompressed or an error occurs. The UDVM can save data between UDVM instances in form of the state items. The state items can be used to make the compression more efficient; they can be used to store the compression algorithms or compression context within a compressed session. A SigComp session endpoint is called compartment. The amount of data that a decompressor can store within each compartment is also severely limited, the default value of the state memory size (sms) is 2048 bytes for SIP endpoints, for instance.
Typically the UDVM when initiated loads the ring buffer part of the available memory with data from compartments such as the SIP dictionary, values which represent commonly used terms in decompressed SIP messages. The UDVM then loads the decompressed message into the ring buffer as it is being decompressed. If the decompressed message is particularly large the loading of the decompressed message can effectively overwrite the initially loaded dictionary. This creates the known problem of reducing the probability of detecting a symbol match in the ring buffer. As the efficiency of the compression and decompression is dependent on the dictionary being used, any degradation of the dictionary reduces the efficiency of the compression.
SUMMARY OF THE INVENTION
Embodiments of the present invention aim to at least partially address the above problem.
There is provided according to the present invention a method for compressing a signalling message in a compressor in a communication system, the compressor comprising a compression memory, wherein the compression memory comprises a first memory in a virtual machine and a second memory external to the virtual machine; the method comprising the steps of: receiving a part of the signalling message; searching the second memory for a copy of the received part of the signalling message; determining a reference to the received part of the signalling message on the basis of the searching step; and outputting the reference as a part of the compressed signalling message representing the received part of the signalling message.
The method may comprise the further step of further searching the first memory for a copy of the received part of the signalling message; and wherein the reference may be determined on the basis of the searching and the further searching steps.
The method may further comprise the further step of prior to the step of receiving a part of the signalling message writing data to the second memory.
The method may comprising the further step of writing a copy of the received part of the signalling message to the first memory after determining a reference to the received part.
The first memory may comprise a ring buffer.
The second memory may comprise at least one of: a dynamic dictionary; and a static dictionary.
The virtual machine may be a universal decompression virtual machine.
According to a second aspect of the present invention there is provided a method for decompressing a compressed signalling message in a decompressor in a communications system, the decompressor comprising a decompression memory, wherein the decompression memory comprises a first memory in a virtual machine and a second memory external to the virtual machine, the method comprising the steps of: receiving a part of the compressed message; determining whether the part of the compressed message comprises a second memory reference; selecting a value on the basis of the determining step, and outputting the value as a part of a decompressed message.
The method may comprise the further step of further determining whether the received part of the compressed message comprises a first memory reference and wherein the value may be selected on the basis of the determining and the further determining steps.
The method may comprise the further step of prior to the step of receiving a part of the compressed message writing data to the second memory.
The method may comprise the further step of writing a copy of the value to the first memory.
When the determining step determines a first memory reference the selecting step may comprise the step of reading the content of the first memory reference from the first memory; wherein the selected value may be the content of the first memory reference.
When the determining step determines a second memory reference the selecting step may comprise the step of reading the content of the second memory reference from the second memory; wherein the selected value may be the content of the second memory reference.
When the determining step determines no first memory reference or no second memory reference the selected value may be the received part of the compressed message.
The virtual machine may be a universal decompression virtual machine.
According to a third aspect of the present invention there is provided a compressor for compressing a signalling message in a communication device operating within a communications system, the compressor comprising: a first memory in a virtual machine; a second memory external to the virtual machine; the virtual machine further comprising: a receiver arranged to receive the content of a part of the signalling message, a comparator arranged to compare the received content with at least one of a content of the first memory and the second memory, a reference generator arranged to receive an output from the comparator, and output a reference value, wherein the reference value output is arranged to be dependent on the output from the comparator, and wherein the reference value output from the compressor is part of the compressed signalling message.
The compressor may further comprise a memory loader arranged to write the content received from the receiver to the first memory.
The first memory may comprise a ring buffer.
The second memory may comprise at least one of: a static dictionary; and a dynamic dictionary.
The virtual machine may be a universal compression virtual machine.
According to a fourth aspect of the present invention there is provided a decompressor for decompressing a signalling message in a communication system, comprising: a first memory in a virtual machine, a second memory external to the virtual machine; the virtual machine further comprising: a receiver arranged to receive a part of the compressed message; a detector arranged to detect whether the received part of the compressed message comprises a reference to the first memory or the second memory and arranged an output dependent on the detection; a value generator arranged to output a value dependent on the output of the detector, wherein the value output is part of a decompressed message.
The decompressor may further comprise a memory loader arranged to write the value generated to the first memory.
The first memory may comprise a ring buffer.
The second memory may comprise at least one of: a static dictionary; and a dynamic dictionary.
The virtual machine may be a universal compression virtual machine.
According to a fifth aspect of the present invention there is provided a computer program product implementing a method for compressing a signalling message in a compressor in a communication system, the compressor comprising a compression memory, wherein the compression memory comprises a first memory in a virtual machine and a second memory external to the virtual machine; the method comprising the steps of: receiving a part of the signalling message; searching the second memory for a copy of the received part of the signalling message; determining a reference to the received part of the signalling message on the basis of the searching step; and outputting the reference as a part of the compressed signalling message representing the received part of the signalling message.
According to a sixth aspect of the present invention there is provided a computer program product implementing a method for decompressing a compressed signalling message in a decompressor in a communications system, the decompressor comprising a decompression memory, wherein the decompression memory comprises a first memory in a virtual machine and a second memory external to the virtual machine, the method comprising the steps of: receiving a part of the compressed message; determining whether the part of the compressed message comprises a second memory reference; selecting a value on the basis of the determining step, and outputting the value as a part of a decompressed message.
BRIEF DESCRIPTION OF THE DRAWINGS
For better understanding of the present invention, reference will now be made by way of example to the accompanying drawings in which:
FIG. 1 shows a schematic view of a communication system environment wherein the invention can be embodied;
FIG. 2 is a schematic view of a typical UDVM memory system showing the operation of a typical dictionary within the memory block;
FIG. 3 shows a schematic view of UDVM memory system in accordance with an embodiment of the invention;
FIG. 4 shows a flow diagram for the operation of the UDVM during a compression operation in accordance with an embodiment of the present invention; and
FIG. 5 shows a flow diagram for the operation of the UDVM during a decompression operation in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Certain embodiments of the present invention will be described in the following by way of example, with reference to the exemplifying architecture of a third generation (3G) mobile communications system. However, it shall be appreciated that the embodiments may be applied to any suitable communication system.
Reference is made to FIG. 1 which shows an example of a network architecture wherein the invention may be embodied. In FIG. 1 an IP Multimedia Network 45 is provided for offering IP multimedia services for IP Multimedia Network subscribers.
As described above, access to IP Multimedia (IM) services can be provided by means of a mobile communication system. A mobile communication system is typically arranged to serve a plurality of mobile user equipment usually via a wireless interface between the user equipment and at least one radio access node such as a base station 31 of the communication system. The mobile communication system may logically be divided between a radio access network (RAN) and a core network (CN).
The base station 31 is arranged to transmit signals to and receive signals from a mobile user equipment 30 via a wireless interface between the user equipment and the radio access network. Correspondingly, the mobile user equipment 30 is able to transmit signals to and receive signals from the radio access network via the wireless interface.
In the shown arrangement the user equipment 30 may access the IMS network 45 via the access network associated with the base station 31 . It shall be appreciated that, although, for clarity reasons FIG. 1 shows a base station of only one radio access network, a typical communication network system usually includes a number of radio access networks.
The 3G radio access network (RAN) is typically controlled by appropriate radio network controller (RNC). This controller is not shown in order to enhance clarity. A controller may be assigned for each base station or a controller can control a plurality of base stations, for example in the radio access network level. It shall be appreciated that the name, location and number of the radio network controllers depends on the system.
The mobile user equipment 30 of FIG. 1 may comprise any appropriate mobile user equipment adapted for Internet Protocol (IP) communication to connect the network. For example, the mobile user may access the cellular network by means of a Personal computer (PC), Personal Data Assistant (PDA), mobile station (MS) and so on. The following examples are described with reference to mobile stations.
One skilled in the art is familiar with the features and operation of a typical mobile station. Thus, it is sufficient to note that the user may use a mobile station for tasks such as for making and receiving phone calls, for receiving and sending data from and to the network and for experiencing multimedia content or otherwise using multimedia services. A mobile station may include an antenna for wirelessly receiving and transmitting signals from and to base stations of the mobile communication network. A mobile station may also be provided with a display for displaying images and other graphical information for the user of the mobile user equipment. Camera means may be provided for capturing still or video images. Speaker means are also typically provided. The operation of a mobile station may be controlled by means of an appropriate user interface such as control buttons, voice commands and so on. Furthermore, a mobile station is provided with a processor entity and a memory means.
It shall be appreciated that although only few mobile stations are shown in FIG. 1 for clarity, a great number of mobile stations may be in simultaneous communication with a communication system.
A core network (CN) typically includes various switching and other control entities and gateways for enabling the communication via a number of radio access networks and also for interfacing a single communication system with one or more communication system such as with other cellular systems and/or fixed line communication systems. In the 3GPP systems the radio access network is typically connected to an appropriate core network entity or entities such as, but not limited to, a serving general packet radio service support node (SGSN) 33 . The radio access network is in communication with the serving GPRS support node via an appropriate interface, for example on an lu interface. The serving GPRS support node, in turn, typically communicates with an appropriate gateway, for example a gateway GPRS support node 34 via the GPRS backbone network 32 . This interface is commonly a switched packet data interface.
In a 3GPP network, a packet data session is established to carry traffic flows over the network. Such a packet data session is often referred as a packet data protocol (PDP) context. A PDP context may include a radio bearer provided between the user equipment and the radio network controller, a radio access bearer provided between the user equipment, the radio network controller and the SGSN 33 , and switched packet data channels provided between the serving GPRS service node 33 and the gateway GPRS service node 34 . Each PDP context usually provides a communication pathway between a particular user equipment and the gateway GPRS support node and, once established, can typically carry multiple flows. Each flow normally represents, for example, a particular service and/or a media component of a particular service. The PDP context therefore often represents a logical communication pathway for one or more flows across the network. To implement the PDP context between user equipment and the serving GPRS support node, at least one radio access bearer (RAB) needs to be established which commonly allows for data transfer for the user equipment. The implementation of these logical and physical channels is known to those skilled in the art and is therefore not discussed further herein.
FIG. 1 shows also a plurality of application servers 50 connected to the exemplifying Internet Protocol (IP) Multimedia network 45 . The user equipment 30 may connect, via the GPRS network 32 and an IMS network 45 , to at least one of the application servers 50 . It shall be appreciated that a great number of application servers may be connected to a data network.
Communication with the application servers is controlled by means of functions of the data network that are provided by appropriate controller entities. For example, in the current third generation (3G) wireless multimedia network architectures it is assumed that several different servers providing various control functions are used for the control. These include functions such as the call session or call state control functions (CSCFs). The call session functions may be divided into various categories. FIG. 1 shows proxy call session control functions (P-CSCF) 35 and 37 and a serving call session control function (S-CSCF) 36 . It shall be appreciated that similar functions may be referred to in different systems with different names.
A user who wishes to use services provided by an application server via the IMS system may need first to register with a serving controller, such as the serving call session control function (S-CSCF) 36 . The registration is required to enable the user equipment to request a service from the multimedia system. As shown in FIG. 1 , communication between the S-CSCF 36 and the user equipment 30 may be routed via at least one proxy call session control function (P-CSCF) 35 . The proxy CSCF 35 thus acts as a proxy which forwards messages from the GGSN 34 to a serving call session control function 36 and vice versa.
The REGISTER message used by the user above is one example of a SIP (session initiation protocol) message. Other request SIP messages include, INVITE which indicates a user or service is being invited to participate in a call session, ACK which confirms that the client has received a final response to an INVITE request, BYE which terminates a call and can be sent by either the caller or the callee, CANCEL which cancels any pending searches but does not terminate a call that has already been accepted, and OPTIONS which queries the capabilities of servers.
As has been described earlier it is known to compress these SIP messages using the protocol set known as SigComp. This protocol set is defined in IETF RFC (request for comments) 3320 “Signaling Compression (SigComp)”. Furthermore in order to perform both compression and decompression within a device a UDVM (universal decompression virtual machine) is initiated for each message to be compressed or decompressed.
The UDVM initiated for a compression procedure is also known as a compressor. A UDVM initiated for a decompression procedure is also known as a decompressor. The UDVM on initiation is defined within a memory space specified by the SigComp protocols. The memory space used in a compression procedure is known as the compression memory space, and similarly the memory space used in a decompression procedure is known as a decompression memory space.
The typical compression algorithms used by the UDVM for SigComp protocol messages and data streams are the various known LZ77 compression algorithm variants. The LZ77 compression algorithm works by storing a history window of the most recently read data and comparing the current data being encoded with the data in the history window. The output compressed stream/message contains references to the position in the history window, and the length of the match. If a match cannot be found within the history window the character itself is simply encoded into the stream and flagged as a ‘literal’. The compressed stream/message therefore comprises two types of symbols, literals and length/position pairs. The most popular variants of the algorithm family are the LZW, LZSS and DEFLATE algorithms. The differences between these lies in the algorithm used to search current data from the history window, the LZSS algorithm uses a simple binary tree search whereas the DEFLATE algorithm uses a hash table search.
The compression space as used in a SigComp procedure comprises a ring buffer which is arranged to store a copy of the previously received symbols of the decompressed message/data stream and which the compression algorithm uses as the history window to search for copies of the currently read symbols. A ring buffer as known in the art is a statically or dynamically allocated block of memory whereby the final memory location is linked to the first memory location in the block. Thus once the end location of the memory block is reached the operation is pointed back to the start location of the memory block to produce a continuous memory block. This process is also known as wrapping round the ring buffer 113 .
A simplified example of the DEFLATE compression algorithm using the ring buffer, as defined in RFC 1951, is shown here for reference:
def DEFLATE(compressed_stream, ring, message):
start = 0
while start < len(message):
s = message[start:]
position, length = ring.search(s)
s = s[:length]
if length > 1:
compressed_stream.append((length, position))
else:
compressed_stream.append(s)
ring.append(s) # Insert match or literal into ring
start += length
The algorithm shown above searches uncompressed parts of the message against data stored in the history window (ring). The search returns the length and the position of the longest match. If no match is found, length is 1, and the first byte of the search contents is inserted into compressed stream as a literal, else the length and position of the match is inserted into compressed stream. Then the compressed part of the message is appended to the ring buffer.
The typical algorithm used involves further steps such as that of backtracking the output stream if a longer match is found.
The LZ77 algorithms in order to improve the efficiency of the compression use previous messages or external dictionaries. As the efficiency of the compression is related to the ability to find prior examples of the input data then the use of previous messages stored in the history windows prevents the inefficiency of the first received symbols from always being inserted as ‘literals’. In order to use these previous messages (also known as dictionaries), they are inserted into the history window prior to receiving the first part to compress. This process is sometimes known as populating the window history.
The SigComp compressors typically use the first received message as their dynamic dictionary.
However when the compressor is compressing a particularly long message or data stream the appending of the currently read message symbol to the ring buffer causes the read message to reach the end of the ring buffer and to overwrite the dictionary first stored. This degradation of the dictionary can often lead to a lowering of the efficiency of the compression algorithm.
Referring now to FIG. 2 a typical decompression memory block 101 is shown as used by a decompressor in decompressing a message/data stream sent using the SigComp protocols. Although for simplicity the message is received and decompressed by a user terminal, the same process and structures required to carry out the process are employed by other communications devices in order to decompress similar messages.
The decompression memory block 101 used by the decompressor comprises a SigComp portion 103 and a UDVM portion 105 . The SigComp portion 103 itself comprises a SigComp header portion 106 for storing any SigComp message header items, a Bytecode portion 107 for storing any received decompression algorithm instructions, and a compressed message portion 109 buffering at least part of the received compressed message or received compressed data stream. In some examples the Bytecode portion is not used as the instruction set used by the UDVM is loaded from a previously stored instruction set.
The UDVM portion 105 comprises a bytecode portion 111 for storing the instructions for carrying out the decompression and a ring buffer 113 . The ring buffer 113 is used by the user terminal UDVM as the decompression ‘history window’ storing data which can be referenced by the received compressed message in order to reconstruct the original message.
The received data stream contains references to known locations within the ring buffer or contains the data itself in the form of a ‘literal’.
FIG. 2 further shows the composition of a ring buffer 113 during three stages of a typical decompression operation.
The first detailed ring buffer memory block 113 a shows the state of the ring buffer 113 just prior to decompressing a first part of the compressed message. The first detailed ring buffer memory block 113 a comprises a dictionary part 115 . The decompressor typically loads these dictionary data parts from state items into the ring buffer 113 either implicitly, when data is stored in the same state item as the bytecode or explicitly.
After the dictionary part 115 is stored, the decompressor is able to receive symbols from the compressed message memory part 109 . If the received symbol is a literal, the symbol itself is inserted into the ring buffer, and furthermore output as part of the decompressed message. If the received symbol refers to a memory location or locations in the ring buffer (defined by a length/position pair), it is copied from the referenced locations of the ring buffer onto the end of ring buffer, and the copied data is furthermore output as part of the decompressed message.
The second detailed ring buffer memory block 113 b shows a typical ring buffer after a first part of the message has been decompressed. The second detailed ring buffer memory block 113 b comprises a dictionary portion 115 a , which is the same as the dictionary portion loaded into the ring buffer prior to decompression and a decompressed message portion 117 a containing the current decompressed message capable of being searched.
The third detailed ring buffer memory block 113 c shows a typical ring buffer after the ring buffer has wrapped round. This occurs when the size of the dictionary part 115 and the decompressed message are larger than the ring buffer 113 . The third detailed ring buffer memory block 113 c comprises a partial dictionary 115 b , a first decompressed message part 117 b and an overwriting decompressed message part 119 . The overwriting decompressed message part 119 has overwritten part of the dictionary as loaded. Although this will not produce a decompression error, as the compressor ring buffer at the equivalent stage has similarly overwritten the loaded dictionaries the overwriting of the dictionaries will have lowered the efficiency of the compression as the dictionaries are typically chosen for their greater compression efficiency qualities—containing often used strings of symbols.
With reference to FIG. 3 an improved decompression memory block 251 incorporating an embodiment of the present invention is shown. Where the improved decompression memory block shares features as used by the typical memory block then the same reference numerals have been used.
The improved decompression memory block 251 comprises a SigComp portion 103 , a UDVM portion 105 , and an external dictionary portion 201 . The SigComp portion 103 itself comprises a SigComp header portion 106 for storing any SigComp message header items, a Bytecode portion 107 for storing any received decompression algorithm instructions, and a compressed message portion 109 buffering at least part of the received compressed message or received compressed data stream. In some examples the Bytecode portion is not used as the instruction set used by the UDVM is loaded from a previously stored instruction set.
The UDVM portion 105 comprises a bytecode portion 111 for storing the instructions for carrying out the decompression and a ring buffer 113 .
The external dictionary portion 201 is used for the storing of known dictionaries to assist the decompression of the compressed message.
In a first embodiment of the present invention the external dictionary portion is allocated the memory addresses directly after the memory addresses used for the ring buffer 113 . Therefore if for example as shown in FIG. 3 the ring buffer was allocated the memory address range from 0000 to 3400, then the external dictionary portion is allocated the memory address range from 3401 to XXXX where XXXX is the final memory address for the external dictionary portion.
In other embodiments of the present invention the external dictionary portion is allocated the memory addresses other than those directly following the ring buffer with the methods applied below, and in particular the searching for a match in the compressor, being modified to take into account the location of the virtual machine memory and the location of the external dictionary portion memory.
In some embodiments of the present invention the external dictionary portion 201 comprises a static dictionary portion 201 a and a dynamic dictionary portion 201 b . In further embodiments of the present invention the external dictionary portion comprises more than one static or dynamic dictionary portion (not shown). In other embodiments of the present invention the external dictionary portion comprises only a static or dynamic portion (not shown).
The improved compression memory similarly comprises a ring buffer and an external dictionary portion.
The use of the external dictionary portion allows the compressor and decompressor to be operated differently from the typical SigComp procedures as described above.
With reference to FIG. 4 a flow diagram of an improved compressor incorporating an embodiment of the present invention is shown.
The first step 301 the message to be compressed is received.
The next step 303 the compressor loads the external dictionary portion with copies of static and/or dynamic dictionaries.
The following step 305 selects the next uncompressed part of the message, If there are no further uncompressed parts then the operation stops.
The following step 307 searches the ring buffer for a copy of the selected uncompressed part.
If a match is detected the next step 308 outputs a reference to the ring buffer in terms of a position, length pair as a part of the compressed data message and a copy of the uncompressed part is appended to the ring buffer. The method then returns to step 305 to select the next uncompressed part.
If no match is detected in the ring buffer the next step is 309 . Step 309 searches the external dictionary portion for a match with the selected uncompressed part.
If a match is detected in the external dictionary portion the next step, 310 , outputs a reference to the external dictionary portion in terms of a position, length pair as a part of the compressed data message and a copy of the uncompressed part is appended to the ring buffer. The method then returns to step 305 to select the next uncompressed part.
If no match is detected in the external dictionary and also therefore in the ring buffer then the next step is 311 . In step 311 the selected portion of the uncompressed message is output as a part of the compressed data message as a ‘literal’ value and a copy of the uncompressed part is also appended to the ring buffer. The method then returns to the step 305 to select the next uncompressed part.
A further example of the method of compression is described with reference to the pseudocode below. In this example the ring portion is searched by ring search and external dictionary portion comprises a first dictionary dict 1 , and a second dictionary dict 2 which are searched by dict 1 .search and dict 2 .search.
def deflate_extra(compressed_stream, ring, message, dict1, dict2):
start = 0
while start < len(message):
s = message[start:]
position, length = ring.search(s)
if dict1:
d_position, d_length = dict1.search(s)
if d_length > length:
position, length = ring.max_position + d_position, d_length
if dict2:
d_postion, d_length = dict2.search(s)
if d_length > length:
position, length = (
ring.max_position + dict1.max_position +
d_position, d_length)
s = s[:length]
if length > 1:
compressed_stream.append((length, position))
else:
compressed_stream.append(s)
ring.append(s) # Insert match or literal into ring
start += length
In both of these examples the use of an external dictionary portion produces the improvement over the previous compressors whereby the appending of the message part is unable to overwrite the dictionary and therefore the compression efficiency produced by the use of the dictionary is not degraded.
With reference to FIG. 5 a flow diagram of an improved decompressor incorporating an embodiment of the present invention is shown.
The first step 401 the message to be decompressed is received.
The next step 403 the decompressor loads the external dictionary portion with copies of static and/or dynamic dictionaries.
The following step 405 selects the next unread part of the message, If there are no further unread parts then the operation stops.
The following step 407 examines the selected part for a reference to the ring buffer.
If a reference match is detected the next step 408 receives the content of the memory reference from the ring buffer as defined by the memory position, and length. The step further outputs the content as a part of the compressed data message and further appends the content to the ring buffer. The method then returns to step 405 to select the next unread part.
If no ring buffer reference match is detected the next step is 409 . Step 409 examines the selected part for a reference to the external dictionary portion.
If an external dictionary portion match is detected the next step, 410 , receives the content of the memory reference from the external dictionary portion as defined by the memory position and length. The step further outputs the content as a part of the compressed data message and further appends the content to the ring buffer. The method then returns to step 405 to select the next uncompressed part.
If no external dictionary portion match is detected and also therefore in the ring buffer then the next step is 411 . In step 411 the selected portion of the compressed message is output as a part of the decompressed data message as the reading of a ‘literal’ value and furthermore a copy of the ‘literal’ is also appended to the ring buffer. The method then returns to the step 405 to select the next uncompressed part.
Although the above improved compression and decompression methods are described above as having two separate search and two reference examination steps, in some embodiments of the present invention the two steps can be combined as a single extended search or examination. These embodiments are advantageous where the external dictionary portion is assigned memory location addresses adjacent to the ring buffer memory locations.
In some further embodiments of the present invention the reference to the ring buffer and/or the external dictionary portion of the memory further comprises an indicator portion to provide an explicit indication, other than the memory location value, as whether the content was matched in the ring buffer or the external dictionary portion.
The examples of the invention have been described in the context of an IMS system and GPRS networks. However, this invention is also applicable to any other standards. Furthermore, the given examples are described in the context of the so called all SIP networks with all SIP entities and communication channels known as PDP contexts. This invention is also applicable to any other appropriate communication systems, either wireless or fixed line systems, communication standards and communication protocols.
Examples of other possible communication systems enabling wireless data communication services, without limiting to these, include third generation mobile communication system such as the Universal Mobile Telecommunication System (UMTS), i-phone or CDMA2000 and the Terrestrial Trunked Radio (TETRA) system, the Enhanced Data rate for GSM Evolution (EDGE) mobile data network. Examples of fixed line systems include the diverse broadband techniques providing Internet access for users in different locations, such as at home and offices. Regardless the standards and protocols used for the communication network, the invention can be applied in all communication networks wherein registration in a network entity is required.
The embodiment of the invention have been discussed in the context of proxy and servicing call state control functions. Embodiments of the invention can be applicable to other network elements where applicable.
Furthermore it is noted that embodiments of the present invention can be controlled by hardware, software or any combination of hardware and software.
It is also noted herein that while the above describes exemplifying embodiments of the invention, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the invention as defined in the appended claims. | A method for compressing a signalling message in a compressor in a communication system. The compressor comprising a compression memory, wherein the compression memory comprises a first memory in a virtual machine and a second memory external to the virtual machine. The method comprising the steps of: receiving a part of the signalling message; searching the second memory for a copy of the received part of the signalling message; and determining a reference to the received part of the signalling message on the basis of the searching step; outputting the reference as a part of the compressed signalling message representing the received part of the signalling message. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a nonprovisional of, and claims the benefit of the filing date of each of the following provisional applications, the entire disclosure of each of which is incorporated herein by reference for all purposes: U.S. Prov. Pat. Appl. No. 60/460,247, entitled “NONINVASIVE ALCOHOL MONITOR,” filed Apr. 4, 2003; U.S. Prov. Pat. Appl. No. 60/483,281, entitled “HYPERSPECTRAL FINGERPRINT READER,” filed Jun. 27, 2003 by Robert K. Rowe et al.; U.S. Prov. Pat. Appl. No. 60/504,594, entitled “HYPERSPECTRAL FINGERPRINTING,” filed Sep. 18, 2003; and U.S. Prov. Pat. Appl. No. ______, entitled “OPTICAL SKIN SENSOR FOR BIOMETRICS,” filed Mar. 10, 2004 (Attorney Docket No. 20204-002620US).
[0002] This application is also related to U.S. patent application Ser. No. 09/874,740, entitled “APPARATUS AND METHOD OF BIOMETRIC DETERMINATION USING SPECIALIZED OPTICAL SPECTROSCOPY SYSTEM,” filed Jun. 5, 2001, the entire disclosures of both of which are incorporated herein by reference for all purposes
BACKGROUND OF THE INVENTION
[0003] This application relates generally to biometrics. More specifically, this application relates to methods and systems for performing biometric measurements with a multispectral imaging sensor, and to methods and systems for measuring in vivo levels of alcohol or other analytes.
[0004] “Biometrics” refers generally to the statistical analysis of characteristics of living bodies. One category of biometrics includes “biometric identification,” which commonly operates under one of two modes to provide automatic identification of people or to verify purported identities of people. Biometric sensing technologies measure the physical features or behavioral characteristics of a person and compare those features to similar prerecorded measurements to determine whether there is a match. Physical features that are commonly used for biometric identification include faces, irises, hand geometry, vein structure, and fingerprint patterns, which is the most prevalent of all biometric-identification features. Current methods for analyzing collected fingerprints include optical, capacitive, radio-frequency, thermal, ultrasonic, and several other less common techniques.
[0005] Most of the fingerprint-collection methods rely on measuring characteristics of the skin at or very near the surface of a finger. In particular, optical fingerprint readers typically rely on the presence or absence of a difference in the index of refraction between the sensor platen and the finger placed on it. When an air-filled valley of the fingerprint is above a particular location of the platen, total internal reflectance (“TIR”) occurs in the platen because of the air-platen index difference. Alternatively, if skin of the proper index of refraction is in optical contact with the platen, then the TIR at this location is “frustrated,” allowing light to traverse the platen-skin interface. A map of the differences in TIR across the region where the finger is touching the platen forms the basis for a conventional optical fingerprint reading. There are a number of optical arrangements used to detect this variation of the optical interface in both bright-field and dark-field optical arrangements. Commonly, a single, quasimonochromatic beam of light is used to perform this TIR-based measurement.
[0006] There also exists non-TIR optical fingerprint sensors. In most cases, these sensors rely on some arrangement of quasimonochromatic light to illuminate the front, sides, or back of a fingertip, causing the light to diffuse through the skin. The fingerprint image is formed due to the differences in light transmission across the skin-platen boundary for the ridge and valleys. The difference in optical transmission are due to changes in the Fresnel reflection characteristics due to the presence or absence of any intermediate air gap in the valleys, as known to one of familiarity in the art.
[0007] Optical fingerprint readers are particularly susceptible to image quality problems due to non-ideal conditions. If the skin is overly dry, the index match with the platen will be compromised, resulting in poor image contrast. Similarly, if the finger is very wet, the valleys may fill with water, causing an optical coupling to occur all across the fingerprint region and greatly reducing image contrast. Similar effects may occur if the pressure of the finger on the platen is too little or too great, the skin or sensor is dirty, the skin is aged and/or worn, or overly fine features are present such as may be the case for certain ethnic groups and in very young children. These effects decrease image quality and thereby decrease the overall performance of the fingerprint sensor. In some cases, commercial optical fingerprint readers incorporate a thin membrane of soft material such as silicone to help mitigate these effects and restore performance. As a soft material, the membrane is subject to damage, wear, and contamination, limiting the use of the sensor without maintenance.
[0008] Biometric sensors, particularly fingerprint biometric sensors, are generally prone to being defeated by various forms of spoof samples. In the case of fingerprint readers, a variety of methods are known in the art for presenting readers with a fingerprint pattern of an authorized user that is embedded in some kind of inanimate material such as paper, gelatin, epoxy, latex, and the like. Thus, even if a fingerprint reader can be considered to reliably determine the presence or absence of a matching fingerprint pattern, it is also critical to the overall system security to ensure that the matching pattern is being acquired from a genuine, living finger, which may be difficult to ascertain with many common sensors.
[0009] Another way in which some biometric systems may be defeated is through the use of a replay attack. In this scenario, an intruder records the signals coming from the sensor when an authorized user is using the system. At a later time, the intruder manipulates the sensor system such that the prerecorded authorized signals may be injected into the system, thereby bypassing the sensor itself and gaining access to the system secured by the biometric.
[0010] A common approach to making biometric sensors more robust, more secure, and less error-prone is to combine sources of biometric signals using an approach sometimes referred to in the art as using “dual,” “combinatoric,” “layered,” “fused,” or “multifactor biometric sensing. To provide enhanced security in this way, biometric technologies are combined in such a way that different technologies measure the same portion of the body at the same time and are resistant to being defeated by using different samples or techniques to defeat the different sensors that are combined. When technologies are combined in a way that they view the same part of the body they are referred to as being “tightly coupled.”
[0011] The accuracy of noninvasive optical measurements of physiological analytes such as glucose, alcohol, hemoglobin, urea, and cholesterol can be adversely affected by variation of the skin tissue. In some cases it is advantageous to measure one or more physiological analytes in conjunction with a biometric measurement. Such dual measurement has potential interest and application to both commercial and law-enforcement markets.
[0012] There is accordingly a general need in the art for improved methods and systems for biometric sensing and analyte estimation using multispectral imaging systems and methods.
BRIEF SUMMARY OF THE INVENTION
[0013] Embodiments of the invention thus provide methods and systems for biometric sensing and physiological analyte estimation. The embodiments of the present invention collect multispectral image data that represent spatio-spectral information from multiple skin features at various depths and positions within an image volume. The information from the different features can be advantageously combined to provide for methods of biometric identification, including identity verification. As well, the multispectral image data may be processed to provide information about the authenticity or liveness state of a sample. The multispectral image data may also be used to ascertain information about the presence and amount of particular physiological analytes that may be present in the tissue at the image location.
[0014] Embodiments of the invention provide methods and systems for assessing skin composition and structure in a certain location on the body using optical techniques. When light of a particular wavelength enters the skin, it is subject to optical interactions that include absorbance and scatter. Due to the optical scatter, a portion of the light will generally be diffusely reflected from the skin after entering the skin at the illumination point. An image of the light thus reflected contains information about the portion of the skin that the light passes through while traveling from the point of illumination to detection. Different wavelengths of light will interact with skin differently. Due to the properties of certain skin components, certain wavelengths of light will interact more or less strongly with certain components and structures. As well, certain wavelengths of light will travel greater distances into and through the skin before being scattered back out of the skin and detected. Accurate measurement of the spatial characteristics of light that is diffusely reflected from skin thus contains information about the components and structures in the skin that interacted with light of a certain wavelength. Similar measurements made using light of multiple and different illumination wavelengths provides additional information about the skin composition and structure.
[0015] In one set of embodiments, a sensor system is provided. An illumination subsystem is disposed to provide light at a plurality of discrete wavelengths to a skin site of an individual. A detection subsystem is disposed to receive light scattered from the skin site. A computational unit is interfaced with the detection system. The computational unit has instructions for deriving a spatially distributed multispectral image from the received light at the plurality of discrete wavelengths. The computational unit also has instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual.
[0016] The identification of the individual may be performed differently in different embodiments. In one embodiment, the instructions for comparing the derived multispectral image with the database comprise instructions for searching the database for an entry identifying a multispectral image consistent with the derived multispectral image. In another embodiment, the instructions for comparing the derived multispectral image with the database comprise instructions for comparing the derived multispectral image with the multispectral image at an entry of the database corresponding to a purported identity of the individual to verify the purported identity.
[0017] The illumination subsystem may comprise a light source that provides the light to the plurality of discrete wavelengths, and illumination optics to direct the light to the skin site. In some instances, a scanner mechanism may also be provided to scan the light in a specified pattern. The light source may comprise a plurality of quasimonochromatic light sources, such as LEDs or laser diodes. Alternatively, the light source may comprise a broadband light source, such as an incandescent bulb or glowbar, and a filter disposed to filter light emitted from the broad band source. The filter may comprise a continuously variable filter in one embodiment. In some cases, the detection system may comprise a light detector, an optically dispersive element, and detection optics. The optically dispersive element is disposed to separate wavelength components of the received light, and the detection optics direct the received light to the light detector. In one embodiment, both the illumination and detection subsystems comprise a polarizer. The polarizers may be circular polarizers, linear polarizers, or a combination. In the case of linear polarizers, the polarizers may be substantially crossed relative to each other.
[0018] The sensor system may comprise a platen to contact the skin site, or the sensor system may be configured for noncontact operation. The platen may be adapted for the skin site to be swiped over a surface of the platen. In one such embodiment, the platen comprises an optically clear roller that the finger can roll across with a swipe motion. In such an embodiment, the instructions for deriving the spatially distributed multispectral image include instructions for building up the multispectral image from light received from different portions of the skin site as the skin site is rolled.
[0019] The illumination subsystem may comprise a plurality of illumination subsystems. In different embodiments, the plurality of discrete wavelengths are provided sequentially or are provided substantially simultaneously and with an identifiable encoding. Suitable wavelengths for the plurality of discrete wavelengths include wavelengths between about 400 nm and 2.5 μm.
[0020] In some embodiments, the sensor system may have additional components to allow the estimation of other parameters. For instance, in one embodiment, the computational system further has instructions for deriving spectral-distribution characteristics from the received light. Such spectral-distribution characteristics may be used to determine an analyte concentration in tissue below a surface of the skin site, such as a concentration of alcohol, glucose, hemoglobin, urea, and cholesterol. In another embodiment, the computational system further has instructions for determining a liveness state from the derived spectral-distribution characteristics.
[0021] In a second set of embodiments, methods are provided for identifying an individual. A skin site of the individual is illuminated at a plurality of discrete wavelengths. Light scattered from the skin site is received. A spatially distributed multispectral image is derived from the received light at the plurality of discrete wavelengths. The derived multispectral image data or one or more of its parts are compared with a database of derived multispectral images. Various of the embodiments include aspects discussed above in connection with embodiments for the sensor system. In some instances, the methods allow generation of measurement sequences that are not constant for all samples. In one embodiment, a sequence of illumination wavelengths is changed between measurements. In another embodiment, the selection of which illumination wavelengths are used to illuminate the skin are changed between measurements.
[0022] In a third set of embodiments, a sensor system is provided. An illumination subsystem is disposed to provide light at a plurality of discrete wavelengths to a sample. A detection subsystem is disposed to receive light scattered within tissue of the sample. A computational unit is interfaced with the detection subsystem. The computational unit has instructions for deriving multispectral characteristics of the received light at the plurality of distinct wavelengths. The computational unit also has instructions for determining a liveness state of the tissue from the derived multispectral characteristics. In one such embodiment, the liveness state is determined by pixelating spatial distributions of the derived multispectral characteristics. An multivariate factor analysis is performed on a matrix having entries in a first dimension corresponding to a pixel of a pixelated spatial distribution and having entries in a second dimension corresponding to one of the plurality of distinct wavelengths. In addition, various of the embodiments may include aspects discussed above in connection embodiments for other sensor systems.
[0023] In a fourth set of embodiments, a method is provided for determining a liveness state of a sample. The sample is illuminated with light at a plurality of discrete wavelengths. Light scattered within tissue of the sample is received. Multispectral characteristics of the received light are derived at the plurality of discrete wavelengths. A liveness state of the tissue is determined from the derived multispectral characteristics to ensure that the derived characteristics of the sample are consistent with the characteristics anticipated from an authentic sample. Various of the embodiments may include aspects discussed above for other sets of embodiments.
[0024] In a fifth set of embodiments, a method is provided for determining a blood-alcohol level of an individual. Electromagnetic radiation emanating from tissue of the individual in response to propagation of electromagnetic radiation into the tissue of the individual is received. Spectral properties of the received electromagnetic radiation are analyzed. The blood-alcohol level is determined from the analyzed spectral properties.
[0025] The spectral properties may be analyzed over specific wavelength ranges in specific embodiments. For example, in one embodiment amplitudes of the received electromagnetic radiation are determined within a wavelength range of 2.1-2.5 μm. This range includes the specific wavelengths of 2.23 μm, 2.26 μm, 2.28 μm, 2.30 μm, 2.32 μm, 2.25 μm , and 2.38 μm, at one or more of which amplitudes may be determined in a specific embodiment. In another embodiment, amplitudes of the received electromagnetic radiation are determined within a wavelength range of 1.5-1.9 μm. This range includes 1.67 μm, 1.69 μm, 1.71 μm, 1.73 μm, 1.74 μm 1.76 μm and 1.78 μm, at one or more of which amplitudes may be determined in a specific embodiment.
[0026] In a sixth set of embodiments, an apparatus is provided for determining a blood-alcohol level of an individual. A receiver is adapted to receive electromagnetic radiation emanating from tissue of the individual in response to propagation of electromagnetic radiation into the tissue of the individual. A computer readable-storage medium is coupled with a process and has a computer-readable program embodied therein for directing operation of the processor. The computer-readable program includes instructions for analyzing spectral properties of the received electromagnetic radiation and instructions for determining the blood-alcohol level from the analyzed spectral properties.
[0027] In some embodiments, the methods and/or apparatus of the invention may be embodied in devices, such as motor vehicles, whose access and/or operation may be dependent on the determination of the blood-alcohol level. Furthermore, the use of alcohol monitoring may be coupled with biometric identifications in some embodiments. For example, access and/or operation of devices embodying combined alcohol-monitoring and biometric-identification devices may be dependent on a combination of alcohol-monitoring and biometric-identification determinations. In one embodiment, the biometric identification is performed with the same multispectral data used to perform the alcohol estimation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings wherein like reference labels are used throughout the several drawings to refer to similar components. In some instances, reference labels include a numerical portion followed by a latin-letter suffix; reference to only the numerical portion of reference labels is intended to refer collectively to all reference labels that have that numerical portion but different latin-letter suffices.
[0029] [0029]FIG. 1 provides a front view of a multispectral biometric sensor in one embodiment of the invention;
[0030] [0030]FIG. 2A provides a side view of a multispectral biometric sensor shown in one embodiment;
[0031] [0031]FIG. 2B provides a side view of a multispectral biometric sensor shown in another embodiment;
[0032] [0032]FIG. 3 provides a front view of a computer tomographic imaging spectrometer (“CTIS”) in one embodiment of the invention;
[0033] [0033]FIG. 4 provides a top view of a swipe sensor in an embodiment of the invention;
[0034] [0034]FIG. 5 illustrates a multispectral datacube generated in accordance with embodiments of the invention;
[0035] [0035]FIG. 6 is a graphical illustration of the effects of skin scatter;
[0036] [0036]FIG. 7 provides a graphical illustration of the effects of blood absorbance;
[0037] [0037]FIG. 8 provides examples of different illumination characteristics that may be used in embodiments of the invention;
[0038] [0038]FIG. 9A provides a flow diagram illustrating a method for using an alcohol monitor in accordance with an embodiment of the invention;
[0039] [0039]FIG. 9B provides a flow diagram illustrating a method for using a combination of an alcohol monitor and a biometric sensor with an embodiment of the invention;
[0040] [0040]FIG. 9C provides a flow diagram illustrating a method for accommodating optical drift in embodiments of the invention; and
[0041] [0041]FIG. 10 provides a schematic representation of a computer system that may be used to manage functionality of alcohol monitors in accordance with embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0042] 1. Overview
[0043] Embodiments of the invention provide methods and systems that allow for the collection and processing of integrated, multifactor biometric measurements. These integrated, multifactor biometric measurements may provide strong assurance of a person's identity, as well as of the authenticity of the biometric sample being taken. In some embodiments, a sensor provides a plurality of discrete optical wavelengths that penetrate the surface of the skin, and scatter within the skin and/or underlying tissue. As used herein, reference to “discrete wavelengths” is intended to refer to sets of wavelengths or wavelength bands that are treated as single binned units—for each binned unit, information is extracted only from the binned unit as a whole, and not from individual wavelength subsets of the binned unit. In some cases, the binned units may be discontinuous so that when a plurality of discrete wavelengths are provided, some wavelength between any pair of the wavelengths or wavelength bands is not provided, but this is not required in all embodiments. In one embodiment, the optical wavelengths are within the ultraviolet—visible—near-infrared wavelength range. A portion of the light scattered by the skin and/or underlying tissue exits the skin and is used to form a multispectral image of the structure of the tissue at and below the surface of the skin. As used herein, the term “multispectral” is intended to be construed broadly as referring to methods and systems that use multiple wavelengths, and thus includes imaging systems that are “hyperspectral” or “ultraspectral” as those terms are understood by those of skill in the art. Because of the wavelength-dependent properties of the skin, the image formed from each wavelength of light is usually different from images formed at other wavelengths. Accordingly, embodiments of the invention collect images from each of the wavelengths of light in such a way that characteristic spectral and spatial information may be extracted by an algorithm applied to the resulting multispectral image data.
[0044] In some applications, it may be desirable to estimate other parameters and characteristics of a body, either independently or in combination with a biometric measurement. For example, in one specific such embodiment, an ability is provided to measure blood-alcohol levels of a person simultaneously with measurement of a fingerprint pattern; such an embodiment has applications to law enforcement as well as to a variety of commercial applications including restricting motor-vehicle access. In this way, the analyte measurement and the identity of the person on whom the measurement is made may be inextricably linked.
[0045] Skin composition and structure is very distinct, very complex, and varies from person to person. By performing optical measurements of the spatio-spectral properties of skin and underlying tissue, a number of assessments may be made. For example, a biometric-identification function may be performed to identify or verify whose skin is being measured, a liveness function may be performed to assure that the sample being measured is live and viable skin and not another type of material, estimates may be made of a variety of physiological parameters such as age gender, ethnicity, and other demographic and anthropometric characteristics, and/or measurements may be made of the concentrations of various analytes and parameters including alcohol, glucose, degrees of blood perfusion and oxygenation, biliruben, cholesterol, urea, and the like.
[0046] The complex structure of skin may be used in different embodiments to tailor aspects of the methods and systems for particular functions. The outermost layer of skin, the epidermis, is supported by the underlying dermis and hypodermis. The epidermis itself may have five identified sublayers that include the stratum comeum, the stratum lucidum, the stratum granulosum, the stratum spinosum, and the stratum germinativum. Thus, for example, the skin below the top-most stratum comeum has some characteristics that relate to the surface topography, as well as some characteristics that change with depth into the skin. While the blood supply to skin exists in the dermal layer, the dermis has protrusions into the epidermis known as “dermal papillae,” which bring the blood supply close to the surface via capillaries. In the volar surfaces of the fingers, this capillary structure follows the structure of the friction ridges on the surface. In other locations on the body, the structure of the capillary bed may be less ordered, but is still characteristic of the particular location and person. As well, the topography of the interface between the different layers of skin is quite complex and characteristic of the skin location and the person. While these sources of subsurface structure of skin and underlying tissue represent a significant noise source for non-imaging optical measurements of skin for biometric determinations or analyte measurements, the structural differences are manifested by spectral features compared through embodiments of the invention.
[0047] In some instances, inks, dyes and/or other pigmentation may be present in portions of the skin as topical coating or subsurface tattoos. These forms of artificial pigmentation may or may not be visible to the naked human eye. However, if one or more wavelengths used by the apparatus of the present invention is sensitive to the pigment, the sensor can be used in some embodiments to verify the presence, quantity and/or shape of the pigment in addition to other desired measurement tasks.
[0048] In general, embodiments of the present invention relate to methods and systems for collecting spatio-spectral information in the form of multispectral images or datacubes. In certain instances, the desired information is contained in just a portion of the entire multispectral datacube. For example, estimation of a uniformly distributed, spectrally active compound may require just the measure spectral characteristics, which can be extracted from the overall multispectral datacube. In such cases, the overall system design may be simplified to reduce or eliminate the spatial component of the collected data by reducing the number of image pixels, even to a limit of a single pixel. Thus, while the systems and methods disclosed are generally described in the context of multispectral imaging, it will be recognized that the invention encompasses similar measurements in which the degree of imaging is greatly reduced, even to the point where there is a single detector element.
[0049] b 2 . Exemplary Embodiments
[0050] One embodiment of the invention is depicted with the schematic diagram of FIG. 1, which shows a front view of a multispectral biometric sensor 101 . The multispectral sensor 101 comprises an illumination subsystem 121 having one or more light sources 103 and a detection subsystem 123 with an imager 115 . The figure depicts an embodiment in which the illumination subsystem 121 comprises a plurality of illumination subsystems 121 a and 121 b, but the invention is not limited by the number of illumination or detection subsystems 121 or 123 . For example, the number of illumination subsystems 121 may conveniently be selected to achieve certain levels of illumination, to meet packaging requirements, and to meet other structural constraints of the multispectral biometric sensor 101 . Illumination light passes from the source 103 through illumination optics 105 that shape the illumination to a desired form, such as in the form of flood light, light lines, light points, and the like. The illumination optics 105 are shown for convenience as consisting of a lens but may more generally include any combination of one or more lenses, one or more mirrors, and/or other optical elements. The illumination optics 105 may also comprise a scanner mechanism (not shown) to scan the illumination light in a specified one-dimensional or two-dimensional pattern. The light source 103 may comprise a point source, a line source, an area source, or may comprise a series of such sources in different embodiments. In one embodiment, the illumination light is provided as polarized light, such as by disposing a linear polarizer 107 through which the light passes before striking a finger 119 or other skin site of the person being studied.
[0051] In some instances, the light source 103 may comprise one or more quasimonochromatic sources in which the light is provided over a narrow wavelength band. Such quasimonochromatic sources may include such devices as light-emitting diodes, laser diodes, or quantum-dot lasers. Alternatively, the light source 103 may comprise a broadband source such as in incandescent bulb or glow bar. In the case of a broadband source, the illumination light may pass through a bandpass filter 109 to narrow the spectral width of the illumination light. In one embodiment, the bandpass filter 109 comprises one or more discrete optical bandpass filters. In another embodiment, the bandpass filter 109 comprises a continuously variable filter that moves rotationally or linearly (or with a combination of rotational and linear movement) to change the wavelength of illumination light. In still another embodiment, the bandpass filter 109 comprises a tunable filter element such as a liquid-crystal tunable filter, an acousto-optical tunable filter, a tunable Fabry-Perot filter or other filter mechanism known to one knowledgeable in the art.
[0052] After the light from the light source 103 passes through the illumination optics 105 , and optionally the optical filter 109 and/or polarizer 107 , it passes through a platen 117 and illuminates the finger 119 or other skin site. The sensor layout and components may advantageously be selected to minimize the direct reflection of the illumination into the detection optics 113 . In one embodiment, such direct reflections are reduced by relatively orienting the illumination subsystem 121 and detection subsystem 123 such that the amount of directly reflected light detected is minimized. For instance, optical axes of the illumination subsystem 121 and the detection subsystem 123 may be placed at angles such that a mirror placed on the platen 117 does not direct an appreciable amount of illumination light into the detection subsystem 123 . In addition, the optical axes of the illumination and detection subsystems 121 and 123 may be placed at angles relative to the platen 117 such that the angular acceptance of both subsystems is less than the critical angle of the system; such a configuration avoids appreciable effects due to total internal reflectance between the platen 117 and the skin site 119 .
[0053] An alternative mechanism for reducing the directly reflected light makes use of optical polarizers. Both linear and circular polarizers can be employed advantageously to make the optical measurement more sensitive to certain skin depths, as known to one familiar in the art. In the embodiment illustrated in FIG. 1, the illumination light is polarized by linear polarizer 107 . The detection subsystem 123 may then also include a linear polarizer 111 that is arranged with its optical axis substantially orthogonal to the illumination polarizer 107 . In this way, light from the sample must undergo multiple scattering events to significantly change its state of polarization. Such events occur when the light penetrates the surface of the skin and is scattered back to the detection subsystem 123 after many scatter events. In this way, surface reflections at the interface between the platen 117 and the skin site 119 are reduced.
[0054] The detection subsystem 123 may incorporate detection optics that comprise lenses, mirrors, and/or other optical elements that form an image of the region near the platen surface 117 onto the detector 115 . The detection optics 113 may also comprise a scanning mechanism (not shown) to relay portions of the platen region onto the detector 115 in sequence. In all cases, the detection subsystem 123 is configured to be sensitive to light that has penetrated the surface of the skin and undergone optical scattering within the skin and/or underlying tissue before exiting the skin.
[0055] The illumination subsystem 121 and detection subsystem 123 may be configured to operate in a variety of optical regimes and at a variety of wavelengths. One embodiment uses light sources 103 that emit light substantially in the region of 400-1000 nm; in this case, the detector 115 may be based on silicon detector elements or other detector material known to those of skill in the art as sensitive to light at such wavelengths. In another embodiment, the light sources 103 may emit radiation at wavelengths that include the near-infrared regime of 1.0-2.5 μm, in which case the detector 115 may comprise elements made from InGaAs, InSb, PbS, MCT, and other materials known to those of skill in the art as sensitive to light at such wavelengths.
[0056] A side view of one of the embodiments of the invention is shown with the schematic drawing provided in FIG. 2A. For clarity, this view does not show the detection subsystem, but does show an illumination subsystem 121 explicitly. The illumination subsystem 121 in this embodiment includes two discrete light sources 203 and 205 that have different wavelength characteristics. For example, the light sources 203 and 205 may be quasimonochromatic sources such as LEDs, which do not require an optical filter. Sources 203 a, 203 b, and 203 c may provide illumination with substantially the same first wavelength while sources 205 a, 205 b, and 205 c may provide illumination with substantially the same second wavelength, different from the first wavelength. As shown, the illumination optics in FIG. 2A are configured to provide flood illumination, but in alternative embodiments could be arranged to provide line, point, or other patterned illumination by incorporation of cylindrical optics, focusing optics, or other optical components as known to those knowledgeable in the art.
[0057] An exemplary measurement sequence for the system shown in FIG. 2A comprising activating the first light sources 203 and collecting a resulting image. After the image is acquired, the first light sources 203 are turned off and the second light sources 205 are activated at a different wavelength, and a resulting image is collected. For a sensor having more than one wavelength of light source, this illumination-measurement sequence is repeated for all the different wavelengths used in the sensor. It will also be appreciated that substantially the same sequence may be used in embodiments in which the wavelength characteristics of light are determined by states of tunable optical filters, variable optical filters, moveable discrete optical filters, and the like. Also, an alternative mechanism for collecting images at multiple wavelengths may incorporate an encoding method to identify light of each wavelength when multiple wavelengths are illuminated at a given time. The data from the entire illumination sequence is then collected in such a way that the individual wavelength responses are determined from the encoding using methods known to those of skill in the art. Illumination techniques thus include round-robin, frequency-division modulation, Hadamard encoding, and others.
[0058] The sequence of illumination of the light sources may be changed from measurement to measurement. This variability may be introduced to thwart replay attacks where a set of valid signals is recorded and replayed at a later time to defeat the biometric sensor. The measurement variability from sample to sample may also extend in some embodiments to using only a subset of available illumination wavelengths, which are then compared with the corresponding subset of data in an enrollment dataset.
[0059] The array of light sources 203 and 205 need not actually be planar as shown in FIG. 2A. For example, in other embodiments, optical fibers, fiber bundles, or fiber optical faceplates or tapers could convey the light from the light sources at some convenient locations to an illumination plane, where light is reimaged onto the finger. The light sources could be controlled by turning the drive currents on and off as LEDs might be. Alternatively, if an incandescent source is used, rapid switching of the light may be accomplished using some form of spatial light modulator such as a liquid crystal modulator or using microelectromechanical-systems (“MEMS”) technology to control apertures, mirrors, or other such optical elements.
[0060] The use of optical components such as optical fibers and fiber bundles may allow the structure of the multispectral biometric sensor to be simplified. One embodiment is illustrated in FIG. 2B, which shows the use of optical fibers and electronic scanning of illumination sources such as LEDs. Individual fibers 216 a connect each of the LEDs located at an illumination array 210 to an imaging surface, and other fibers 216 b relay the reflected light back to the imaging device 212 , which may comprise a photodiode array or CCD array. The set of fibers 216 a and 216 b thus defines an optical fiber bundle 214 used in relaying light.
[0061] Another embodiment of the invention is shown schematically with the front view of FIG. 3. In this embodiment, the multispectral biometric sensor 301 comprises a broadband illumination subsystem 323 and a detection subsystem 325 . As for the embodiment described in connection with FIG. 1, there may be multiple illumination subsystems 323 in some embodiments, with FIG. 3 showing a specific embodiment having two illumination subsystems 323 . A light source 303 comprised by the illumination subsystem 323 is a broadband illumination source such as an incandescent bulb or a glowbar, or may be any other broadband illumination source known to those of skill in the art. Light from the light source 303 passes through illumination optics 305 and a linear polarizer 307 , and may optionally pass through a bandpass filter 309 used to limit the wavelengths of light over a certain region. The light passes through a platen 117 and into a skin site 119 . A portion of the light is diffusely reflected from the skin 119 into the detection subsystem 325 , which comprises imaging optics 315 and 319 , a crossed linear polarizer 311 , and a dispersive optical element 313 . The dispersive element 313 may comprise a one- or two-dimensional grating, which may be transmissive or reflective, a prism, or any other optical component known in the art to cause a deviation of the path of light as a function of the light's wavelength. In the illustrated embodiment, the first imaging optics 319 acts to collimate light reflected from the skin 119 for transmission through the crossed linear polarizer 311 and dispersive element 313 . Spectral components of the light are angularly separated by the dispersive element 313 and are separately focused by the second imaging optics 315 onto a detector 317 . As discussed in connection with FIG. 1, the polarizers 307 and 311 respectively comprised by the illumination and detection subsystems 323 and 325 act to reduce the detection of directly reflected light at the detector 317 .
[0062] The multispectral image generated from light received at the detector is thus a “coded” image in the manner of a computer tomographic imaging spectrometer (“CTIS”). Both wavelength and spatial information are simultaneously present in the resulting image. The individual spectral patterns may be obtained by mathematical inversion or “reconstruction” of the coded image.
[0063] The embodiments described above in connection with FIGS. 1-3 are examples of “area” sensor configurations. In addition to such area sensor configurations, multispectral imaging sensors may be configured as “swipe” sensors in some embodiments. One example of a swipe sensor is shown in top view with the schematic illustration of FIG. 4. In this figure, the illumination region 403 and detection region 405 of a sensor 401 are substantially collinear. In some embodiments of a swipe sensor 401 , there may be more than a single illumination region. For example, there may be a plurality of illumination regions arranged on either side of the detection region 405 . In some embodiments, the illumination region 403 may partially or fully overlap the detection region 405 . The multispectral image data are collected with the sensor 401 by swiping a finger or other body part across the optically active region, as indicated by the arrow in FIG. 4. The corresponding linear sensor may be a stationary system or a roller system that may further include an encoder to record the position information and aid in stitching a full two-dimensional image from a resulting series of image slices as known to one knowledgeable in the art. When the roller system is used, a fingertip or other skin site may be rolled over a roller that is transparent to the wavelengths of light used. The light is then sequentially received from discrete portions of the skin site, with the multispectral image being built up from light received from the different portions.
[0064] The polarizers included with some embodiments may also be used to create or further accentuate the surface features. For instance, if the illumination light is polarized in a direction parallel (“P”) with the sampling platen and the detection subsystem incorporates a polarizer in a perpendicular orientation (“S”), then the reflected light is blocked by as much as the extinction ratio of the polarizer pair. However, light that crosses into the fingertip at a ridge point is optically scattered, which effectively randomizes the polarization. This allows a portion, on the order of 50%, of the absorbed and re-emitted light to be observed by the S-polarized imaging system.
[0065] The systems described in connection with the specific embodiments above are illustrative and are not intended to be limiting. There are numerous variations and alternatives to the exemplary embodiments described above that are also within the intended scope of the invention. In many instances, the layout or order of the optical components may be changed without substantially affecting functional aspects of the invention. For example, in embodiments that-use broadband illumination sources and one or more optical filters, the filter(s) may be located at any of a variety of points in both the illumination and detection subsystems. Also, while the figures show the finger or other skin site from which measurements are made being in contact with the platen, it will be evident that substantially the same measurements may be made without such contact. In such instances, the optical systems for illumination and detection may be configured to illuminate and image the skin site at a distance. Some examples of such systems are provided in U.S. Prov. Pat. Appl. No. ______, entitled “OPTICAL SKIN SENSOR FOR BIOMETRICS,” filed Mar. 10, 2004 (Attorney Docket No. 20204-002620US), which has been incorporated by reference.
[0066] The embodiments described above produce a set of images of the skin site at different wavelengths or produce data from which such a set may be produced using reconstruction techniques, such as in the particular case of the CTIS or encoded illumination subsystems. For purposes of illustration, the following discussion is made with reference to such a set of spectral images, although it in not necessary to produce them for subsequent biometric processing in those embodiments that do not generate them directly. An illustrative set of multispectral images is shown in FIG. 5, with the set defining a multispectral datacube 501 .
[0067] One way to decompose the datacube 501 is into images that correspond to each of the wavelengths used in illuminating the sample in the measurement process. In the figure, five separate images 503 , 505 , 507 , 509 , and 511 are shown, corresponding to five discrete illumination wavelengths and/or illumination conditions (e.g. illumination point source at position X, Y). In an embodiment where visible light is used, the images might correspond, for example, to images generated using light at 450 nm, 500 nm, 550 nm, 600 nm, and 650 nm. Each image represents the optical effects of light of a particular wavelength interacting with skin and, in the case of embodiments where the skin is in contact with a platen during measurement, represents the combined optical effects of light of a particular wavelength interacting with skin and also passing through the skin-platen interface. Due to the optical properties of skin and skin components that vary by wavelength, each of the multispectral images 503 , 505 , 507 , 509 , and 511 will be, in general, different from the others
[0068] The datacube may thus be expressed as R(X S , Y S , X 1 , Y 1 , λ) and describes the amount of diffusely reflected light of wavelength λ seen at each image point X 1 , Y 1 when illuminated at a source point X S , Y S . Different illumination configurations (flood, line, etc.) can be summarized by summing the point response over appropriate source point locations. A conventional non-TIR fingerprint image F(X 1 , Y 1 ) can loosely be described as the multispectral data cube for a given wavelength, λ o , and summed over all source positions:
F ( X I , Y I ) = ∑ Y S ∑ X S R ( X S , Y S , X I , Y I , λ 0 ) .
[0069] Conversely, the spectral biometric dataset S(λ) relates the measured light intensity for a given wavelength λ to the difference {right arrow over (D)} between the illumination and detection locations:
S ( {right arrow over (D)}, λ)=( X 1 −X S , Y 1 −Y S , λ).
[0070] The multispectral datacube R is thus related to both conventional fingerprint images and to spectral biometric datasets. The multispectral datacube R is a superset of either of the other two data sets and contains correlations and other information that may be lost in either of the two separate modalities.
[0071] The optical interactions at the skin-platen interface will be substantially the same at all wavelengths since the optical qualities of the platen material and the skin are not generally significantly different over the range of wavelengths used and the optical interface does not change substantially during the measurement interval. Light migrated from the skin to the platen, as well as from the platen to the skin, will be affected by Fresnel reflections at the optical interfaces. Thus, light that traverses an air gap will be less intense in the receiving medium than light that does not cross an air gap. This phenomenon forms just one portion of the image information that is contained in the multispectral datacube.
[0072] The light that passes into the skin and/or underlying tissue is generally affected by different optical properties of the skin and/or underlying tissue at different wavelengths. Two optical effects in the skin and/or underlying tissue that are affected differently at different wavelengths are scatter and absorbance. Optical scatter in skin tissue is generally a smooth and relatively slowly varying function of wavelength, as shown in FIG. 6. Conversely, absorbance in skin is generally a strong function of wavelength due to particular absorbance features of certain components present in the skin. For example, blood has certain characteristic absorbance features as shown in FIG. 7. In addition to blood, other substances that have significant absorbance properties in the spectral region from 400 nm to 2.5 μm and that are found in skin and/or underlying tissue include melanin, water, carotene, biliruben, ethanol, and glucose.
[0073] The combined effect of optical absorbance and scatter causes different illumination wavelengths to penetrate the skin to different depths. This effect is illustrated schematically in FIG. 8, which depicts the optical scattering that occurs in tissue for three different illumination points on the surface of skin at three different wavelengths, shown with the same scale. This phenomenon effectively causes the different spectral images to have different and complementary information corresponding to different volumes of the illuminated tissue. In particular, the capillary layers close to the surface of the skin have distinct spatial characteristics that can be imaged using wavelengths of light in which blood is strongly absorbing.
[0074] Thus, the multispectral image datacube contains spatio-spectral information from multiple sources. Merely by way of example, for the case of a measurement taken on the fingertip in contact with a platen, the resulting datacube contains effects due to: (i) the optical interface between the fingertip and the platen, similar to information contained in a conventional non-TIR fingerprint; (ii) the overall spectral characteristics of the tissue, which are distinct from person to person; (iii) the blood vessels close to the surface of the skin, similar to vein imaging; and (iv) the blood vessels and other spectrally active structures distributed deeper in the tissue. As such, embodiments of the invention provide a mechanism for extracting biometric data from multiple sources within the fingertip or other skin site being measured, thereby providing multifactor biometric-sensing applications.
[0075] Because of the complex wavelength-dependent properties of skin and underlying tissue, the set of spectral values corresponding to a given image location has spectral characteristics that are well-defined and distinct. These spectral characteristics may be used to classify the multispectral image data on a pixel-by-pixel basis. This assessment may be performed by generating typical tissue spectral qualities from a set of qualified images. For example, the multispectral data shown in FIG. 5 may be reordered as an N×5 matrix, where N is the number of image pixels that contain data from living tissue, rather than from a surrounding region of air. An eigenanalysis or other factor analysis performed on this set matrix produces the representative spectral features of these tissue pixels. The spectra of pixels in a later data set may then be compared to such previously established spectral features using metrics such as Mahalanobis distance and spectral residuals. If more than a small number of image pixels have spectral qualities that are inconsistent with living tissue, then the sample is deemed to be non-genuine and rejected, thus providing a mechanism for incorporating antispoofing methods in the sensor based on determinations of the liveness of the sample.
[0076] Similarly, in an embodiment where the sample is a fingertip, the multispectral image pixels are classified as “ridge,” “valley,” or “other,” based on their spectral qualities. This classification can be performed using discriminant analysis methods such as linear discriminant analysis, quadratic discriminant analysis, principle component analysis, neural networks, and others known to those of skill in the art. Since ridge and valley pixels are contiguous on a typical fingertip, in some instances multispectral data from the local neighborhood around the image pixel of interest are used to classify the image pixel. In this way, a conventional fingerprint image is extracted from the sensor for further processing and biometric assessment. The “other” category may indicate image pixels that have spectral qualities that are different than anticipated in a genuine sample. A threshold on the total number of pixels in an image classified as “other” may be set. If this threshold is exceeded, the sample may be determined to be non-genuine and appropriate indications made and actions taken.
[0077] Biometric determinations of identity may be made using the entire datacube or particular portions thereof. For example, appropriate spatial filters may be applied to separate out the lower spatial frequency information that is typically representative of deeper spectrally active structures in the tissue. The fingerprint data may be extracted using similar spatial frequency separation and/or the pixel classification methods disclosed above. The spectral information can be separated from the active portion of the image in the manner discussed above. These three portions of the datacube may then be processed and compared to the corresponding enrollment data using methods known to one familiar with the art to determine the degree of match. Based upon the strength of match of these characteristics, a decision can be made regarding the match of the sample with the enrolled data.
[0078] As previously noted, certain substances that may be present in the skin and underlying tissue have distinct absorbance characteristics. For example, ethanol has characteristic absorbance peaks at approximately 2.26 μm, 2.30 μm, and 2.35 μm, and spectral troughs at 2.23 μm, 2.28 μm, 2.32 μm, and 2.38 μm. In some embodiments, noninvasive optical measurements are performed at wavelengths in the range of 2.1-2.5 μm, more particularly in the range of 2.2-2.4 μm. In an embodiment that includes at least one of the peak wavelengths and one of the trough wavelengths, the resulting spectral data are analyzed using multivariate techniques such as partial least squares, principal-component regression, and others known to those of skill in the art, to provide an estimate of the concentration of alcohol in the tissue, as well as to provide a biometric signature of the person being tested. While a correlation to blood-alcohol level may be made with values determined for a subset of these wavelengths, it is preferable to test at least the three spectral peak values, with more accurate results being obtained when the seven spectral peak and trough values are measured.
[0079] In other embodiments, noninvasive optical measurements are performed at wavelengths in the range of 1.5-1.9 μm, more particularly in the range of 1.6-1.8 μm. In specific embodiments, optical measurements are performed at one or more wavelengths of approximately 1.67 μm, 1.69 μm, 1.71 μm, 1.73 μm, 1.74 μm 1.76 μm and 1.78 μm. The presence of alcohol is characterized at these wavelengths by spectral peaks at 1.69 μm, 1.73 μm, and 1.76 μm and by spectral troughs at 1.67 μm, 1.71 μm, 1.74 μm, and 1.78 μm. Similar to the 2.1-2.5 μm wavelength range, the concentration of alcohol is characterized by relative strengths of one or more of the spectral peak and trough values. Also, while a correlation to blood-alcohol level may be made with values determined for a subset of these wavelengths in the 1.5-1.9 μm range, it is preferable to test at least the three spectral peak values, with more accurate results being obtained when the seven spectral peak and trough values are measured.
[0080] A small spectral alcohol-monitoring device may be embedded in a variety of systems and applications in certain embodiments. The spectral alcohol-monitoring device can be configured as a dedicated system such as may be provided to law-enforcement personnel, or may be integrated as part of an electronic device such as an electronic fob, wristwatch, cellular telephone, PDA, or any other electronic device, for an individual's personal use. Such devices may include mechanisms for indicating to an individual whether his blood-alcohol level is within defined limits. For instance, the device may include red and green LEDs, with electronics in the device illuminating the green LED if the individual's blood-alcohol level is within defined limits and illuminating the red LED if it is not. In one embodiment, the alcohol-monitoring device may be included in a motor vehicle, typically positioned so that an individual may conveniently place tissue, such as a fingertip, on the device. While in some instances, the device may function only as an informational guide indicating acceptability to drive, in other instances ignition of the motor vehicle may affirmatively depend on there being a determination that the individual has a blood-alcohol level less than a prescribed level.
[0081] This type of action is an example of a more general set of actions that may be performed with the alcohol-monitoring devices of the invention. Such general methods as they may be implemented by the alcohol-monitoring device are summarized in FIG. 9A. At block 902 , an alcohol-level determination is performed with spectral information as described above. At block 904 , a determination is made from the alcohol-level determination whether the alcohol level is within prescribed limits. If it conforms with such limits, a first action is taken at block 906 . This action may correspond, for example, to allowing ignition of a motor vehicle, allowing a pilot to enter an aircraft, allowing an employee to enter a workplace, and the like. If the alcohol-level determination does not conform to the prescribed limits, a second action is taken at block 908 . This action may correspond, for example, to preventing ignition of a motor vehicle, prohibiting access by a pilot to an aircraft or an employee to a workplace, and the like.
[0082] In some instances, the blood-alcohol determination may be coupled with a biometric determination. An overview of such combined methods is provided with the flow diagram of FIG. 9B. At block 910 , an alcohol-level determination is performed using spectral information as described above. Different actions may be taken depending on whether the determined alcohol level is within prescribed limits, as tested at block 912 . If the alcohol limit is outside the prescribed limits, a first action may be taken at block 914 , such as prohibiting ignition of a motor vehicle. Access to the motor vehicle might, however, not automatically be granted by the system merely because the alcohol level was within the prescribed limits. As indicated at block 916 , a determination that those limits are met may instead prompt a biometric test to be performed so that a check of an individual's identity is performed at block 918 . If the person is identified as a specific person, such as the owner of the motor vehicle, a second action allowing access to the motor vehicle may be taken at block 920 . If the person identified is not the specific person, a third action may be taken at block 922 . This third action could correspond, for example, to the first action so that access to the motor vehicle is restricted, but could alternatively correspond to an action different from the first or second actions. For example, the third action could result in the sounding of an alarm to indicate that an unknown person is attempting to gain control of a motor vehicle.
[0083] The flow diagrams in FIG. 9B provide examples where a biometric test may be used to override a decision that would be made in response to a particular result of an alcohol-monitoring test. In other embodiments, a biometric test could be performed in response to the contrary result for the alcohol-monitoring test, or could be performed irrespective of the result of the alcohol-monitoring test. In such cases, different actions could be taken depending on the various combinations of results of the alcohol-level and biometric determinations. Furthermore, there is no need for the alcohol-monitoring test to precede the biometric determination; the tests could be performed in a different order or simultaneously in different embodiments.
[0084] In some embodiments, correction is made for optical drift by determining an optical correction from use of the alcohol-monitoring device on a reference sample. An overview of a method for making such a correction is provided in FIG. 9C. At block 932 , optical sources of the alcohol-monitoring device are used to illuminate the reference sample, which could conveniently comprise an alcohol-water mixture. At block 934 , a detector of the alcohol-monitoring device is used to measure spectral characteristics of light after propagation through the reference sample. These spectral characteristics are usually stored for later application to a variety of different spectral determinations. Thus, at block 936 , the light sources of the alcohol-monitoring device are used to illuminate tissue of an individual and at block 938 , the spectral characteristics of light propagated through the tissue are measured with a detector of the alcohol-monitoring device. Before making a determination of blood-alcohol level using the peak-trough comparison analysis described above, the spectral characteristics are corrected in accordance with the spectral characteristics determined from the reference sample at block 940 . Changes that occur to the light sources, detectors, optical filters, lenses, mirrors, and other components in the optical chain will affect both the in vivo measurement and the reference sample in a similar manner. Processing of the in vivo sample in conjunction with the alcohol-bearing reference sample thus compensates for such optical effects.
[0085] Management of the functionality discussed herein for the alcohol-monitoring device may be performed with a computer system. The arrangement shown in FIG. 10 includes a number of components that may be appropriate for a larger system; smaller systems that are integrated with portable devices may use fewer of the components. FIG. 10 broadly illustrates how individual system elements may be implemented in a separated or more integrated manner. The computational device 1000 is shown comprised of hardware elements that are electrically coupled via bus 1026 , which is also coupled with the alcohol-monitoring device 1055 . The hardware elements include a processor 1002 , an input device 1004 , an output device 1006 , a storage device 1008 , a computer-readable storage media reader 1010 a, a communications system 1014 , a processing acceleration unit 1016 such as a DSP or special-purpose processor, and a memory 1018 . The computer-readable storage media reader 1010 a is further connected to a computer-readable storage medium 1010 b, the combination comprehensively representing remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing computer-readable information. The communications system 1014 may comprise a wired, wireless, modem, and/or other type of interfacing connection and permits data to be exchanged with external devices.
[0086] The computational device 1000 also comprises software elements, shown as being currently located within working memory 1020 , including an operating system 1024 and other code 1022 , such as a program designed to implement methods of the invention. It will be apparent to those skilled in the art that substantial variations may be used in accordance with specific requirements. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets), or both. Further, connection to other computing devices such as network input/output devices may be employed
[0087] [0087]FIG. 10 also indicates that a biometric sensor 1056 may also be coupled electrically via bus 1026 for use in those embodiments that combine the use of the alcohol-monitoring device 1055 with the biometric sensor 1056 . As previously mentioned, the biometric sensor 1056 may also use spectral information in making identifications of individuals, although this is not required. The computational device 1000 may equally well be adapted to coordinate the function of any other type of biometric identification device with the alcohol-monitoring device as described above.
[0088] Other analytes in the body may be estimated using similar techniques by ensuring that the multispectral data that are measured by the sensor include characteristic absorbance features of the analyte of interest. Such analyte estimation techniques may be further aided using a method similar to the pixel classification technique described above. In such embodiments, the multispectral image pixels are classified as “ridge” or “valley,” or are classified according to another appropriate classification such as “blood vessel” or “no vessel.” A subset of the multispectral data is the extracted and used for the analyte estimation based on the pixel classification. This procedure reduces the variability of the estimation due to optical and physiological differences across the image plane.
[0089] Furthermore, the structural configurations for the sensors described herein may vary to reflect consideration of such facts as the cost and availability of off-the-shelf components, materials, designs, and other issues. Certain configurations may be easier, less expensive, and quicker to build than others, and there may be different considerations that affect prototype and volume productions differently. For all embodiments, the optical geometry should be carefully considered. The region of skin that returns a detectable amount of diffusely reflected light varies considerably as a function of the illumination wavelength.
[0090] For instance, for visible and very near infrared illumination, the short-wavelength illumination points may be laid out on a denser array than the long-wavelength points. It may be preferable for the embodiments that use swipe configurations to have the timing of the illumination and the image acquisition be sufficient for a relatively quick motion across the optically active region of the sensor. A modulated illumination method may advantageously be used for these types of sensors.
[0091] Thus, having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Accordingly, the above description should not be taken as limiting the scope of the invention, which is defined in the following claims. | Methods and systems are provided for biometric sensing. An illumination subsystem provides light at discrete wavelengths to a skin site of an individual. A detection subsystem receives light scattered from the skin site. A computational unit is interfaced with the detection system. The computational unit has instructions for deriving a spatially distributed multispectral image from the received light at the discrete wavelengths. The computational unit also has instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual. | 0 |
[0001] This application is based on U.S. Provisional Application Ser. No. 60/565,660, Filed on Apr. 27, 2004
FIELD OF INVENTION
[0002] The field of invention is molding compounds that are particularly suitable to be molded into an article that will produce heat and not burn when an electric current is passed through the article. These articles include applications in HVAC, seating, inductance heating and anti-fouling applications. These could include, but not be limited to items such as blower housings, stadium style seating, heated floors and wall and ceiling panels, ice guard, and low conductivity surfaces to inhibit barnacle growth or other undesired parasites. These compounds are generally liquid thermosetting molding resins typically characterized as bulk molding compositions (“BMC”), sheet molding compositions (“SMC”), and/or thick molding compositions (“TMC”). They can be used in molding processes such as compression, transfer, injection/compression molding and injection molding.
[0003] Products molded from the composition of this invention desirably have a resistance in the range of 1 to 10 ohms and preferably 1.5 to 7 ohms and more preferably 3.0 to 4.0 ohms when tested as 6″×6″ by 0.125 “panels” as described herein and they achieve this resistance while maintaining flame retardance, preferably achieving a passable flame retardance value when tested in accordance with UL test # 94 V0 and 94 5V tested to a thickness of 0.060 inch. They also have adequate glass transition temperatures and desirable surface characteristics; heat, low temperature, corrosion and shrink resistance; low odor, sound damping strength; and cost. Desirably the compositions include a thermoset resin matrix such as a terephthalate polyester which can include blends of polyester and/or vinyl ester with a significant loading of conductive inorganic filler, typically graphite and optimally blends of graphites. The compositions also include flame and sound retardant additives, and glass fibers. They are further formulated to meet the desired molding characteristics; to withstand the operating temperatures to which they will be exposed; and to have a predetermined strength and a desirable user interface including appearance, and odor. Typically, the compounds will have a glass transition temperature from about 320° F. (160° C.) to about 343° F. (173° C.).
[0004] The molding compositions in accordance with the invention can be formed into articles having complex configurations, including configurations with fluid curving lines and further which include integrally molded functional elements, such as rims, flanges, bosses, male and female mating parts. These articles can be relatively large and have the mechanical strength even at elevated temperatures to be self-supporting and to support other elements depending on the application. They also can incorporate the resistive heating quality into the molded article.
[0005] The invention also relates to articles which are molded from the previously described compounds. These molded articles include, but are not limited to combination heater/blower housings, air handlers, heating surfaces, ice guard, flooring, seating, and boat and dock surfaces.
BACKGROUND OF THE INVENTION
[0006] The present invention recognizes the manufacturing efficiency of molding complex parts from conductive polymeric compositions which can be subjected to a current to induce inductive heating or a mild current, and which are safe to use for these applications by virtue of the fact that they will not burn at the desired thickness. These compounds either replace metal structures that have typically been used for these applications and which require numerous bending, forming and machining processes, or even present the opportunity to develop new articles. For example, in the past, furnaces and air handlers have included a heater which runs in the vicinity of 1000° F. (538° C.), and a blower which expels the heated air from the heater. The housing for the blower has been formed from sheet metal. It typically has curving side walls joined at right angles to planar front and back walls. Thus, it requires complex fabrication steps to produce it. The present invention relates to a combination blower housing and heater. These functions are combined in a conductive molded blower housing that will generate heat in response to a low current. This blower can operate as the blower and heater and can maintain the same thermal efficiency while operating at temperatures ranging from about 250° F. (121° C.) to about 400° F. (204° C.), and more preferably in the range of from about 300° F. (149° C.) to about 350 ° F. (177° C.). These blower housings can reduce the height and width requirement by about two to about five inches for air handlers and thus have wider applications, including apartment and multiple residence dwellings. They are also useful in commercial heating applications. They have suitable strength, temperature and aesthetic characteristics to allow them to replace metal in known applications in the HVAC and other market areas. The housing can include surface perturbations such as ripples, grooves, or ribs, in the air flow channel which increase heat transfer and thereby improve the thermal efficiency of the furnace or air handler. The heating elements and connecting electrodes can be molded into the housing, further reducing fabrication steps.
[0007] There are further applications for these conductive molding compounds in providing alternatives to traditional conductive materials, which often involve greater labor expense to manufacture into complex parts. In particular, in instances where the demand justifies significant volumes of a product, polymer-molding expenses may prove far more cost effective than comparable machining and fabricating expenses for metal materials. However it is not a trivial task to achieve the desired level of conductivity, desirable molding characteristics and the critical safety requirements in one material. Generally, significant weight percentages of an appropriate filler in a polymeric matrix are necessary to achieve satisfactory levels of conductivity and for many applications and resins reinforcement, such as fiber, may be necessary to achieve the desired strength and corrosion resistance over the desired temperature range. However, these high load levels lead to problems with the strength, durability, and moldability and sound resistance of the resulting composition
[0008] One area in particular where it would be beneficial to solve the previously mentioned strength, durability, and molding issues is for application in heating and air conditioning, as has been previously discussed. Additional heating applications include heated wall panels, ceiling panels, roofing underlayment, flooring and seating. For example, inductive heating is currently used for flooring in which a conductive mat is used under a ceramic tile floor. While ceramic tile may be beautiful, it is hard, and expensive. It is particularly expensive to install the previously described inductive heating means for large floor surfaces. The current invention would allow the mat to be made from sheet material that could be laid under tile, or could even be constructed directly into the floor as a sheet or as tile, with all of the advantages of a polymeric floor surface. Similarly, wall panels or ceiling panels could combine building functionality with the benefits of heating.
[0009] Another area that could benefit from the present invention is heated seating, such a stadium seating, or other outdoor applications, such as ski lifts. Bench seating can incorporate the heating sheet, or the composition can be molded into a contoured seat. In addition, the compounds could be useful for applications in which a mild current is desirable, such as for anti-fouling. The compounds could be molded into plates that are used on boat hulls, or docks to discourage barnacle growth, or could be incorporated directly into the hull or dock. Similarly, the material could be used to discourage birds from roosting on ledges if the material is used to induce a magnetic current.
SUMMARY OF THE INVENTION
[0010] The present invention provides conductive molding compositions that meet the safety, strength, and aesthetic requirements to allow for use in inductive and mildly to moderately conductive molded articles. These compounds are typically liquid thermoset resins with a moderate level of graphite or graphite blend to provide the desired conductivity. Additional additives include initiators, flame retardants, and reinforcing fillers and molding agents characteristics to permit the compositions to be molded into the desired shape by a variety of types of molding processes. Optimally, the base resin can include a polyester resin and more specifically can be a terephthalate polyester blended with a epoxy novalac vinyl ester and a loading of graphite of from about 10 to about 80%, and more desirably from about 20 to about 50%, and in particular about 35% to 45% by weight loading of graphite.
[0011] In particular, the formulations involve the use of a resin matrix with significant loadings of a conductive filler; various additional additives, such as flame retardants, sound dampeners, initiators, inhibitors, mold-release agents, shrink control additives, fiber reinforcement, viscosity agents, flow modifiers, thickeners, styrene, and carbon black or pigments or other desirable additives. The conductive filler is an inorganic filler which is desirably particulate graphite which is a blend. Conductive polymers may be used as a conductivity enhancer with the graphite. In addition depending on the application, silver coated ceramic fibers can be added to improve the overall electrical properties.
[0012] It is anticipated that properties such as the moldablity, coefficient of thermal expansion, electrical and thermal conductivity, shrink resistance and mechanical properties will be in the desired ranges as a result of the use of the present invention.
[0013] The foregoing improvements in specimens molded from these compositions enable the low cost mass production of articles used in the heating and surface low conductivity areas, and further allow for the combination of functions in a single article.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an illustration of a furnace incorporating a heater/blower housing that can be made in accordance with the present invention;
[0015] FIG. 2 is an illustration of the heater/blower housing of FIG. 1 ;
[0016] FIG. 3 is a graph of the sound speed versus temperature for a composition having loadings of glass fiber ranging between 8% and 23%;
[0017] FIG. 4 is a similar graph comparing conductive and non-conductive compounds;
[0018] FIG. 5 is a graph showing the conductance of conductive and non-conductive media for test plaques;
[0019] FIG. 6 is a graph showing the conductance for actual housing molded from conductive and non-conductive housings;
[0020] FIG. 7 is a thermal picture of an actual heater/blower housing molded using a compound in accordance with the present invention; and
[0021] FIG. 8 is a SMC machine which can be used which to compound the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The invention relates to improvements to conductive molding compositions for use in inductive heating and surface low conductivity applications, and to the articles that are made from these compositions. In particular, the compositions can be used in injection molding processes, in transfer molding, in compression molding processes, and in injection/compression molding processes. These processes are cost effective because they eliminate labor intensive machining, and because of repeatability with respect to shot to shot molding. The processes further have better ability to control shot to shot cross parting line thickness. Further these molding processes enable the production of complex configurations that have integral functional features and that have significant concentrations of fillers including conductive filler and fiber reinforcement.
[0023] FIG. 1 shows a typical hot air furnace 10 of the prior art. This furnace includes the blower 13 is mounted within a housing 12 that supports the blower motor, and directs the air in the furnace cabinet 14 . The air is directed over the heating coils 16 that can reach temperatures up to about 1,000° F. FIG. 2 shows a side view of the blower housing 12 which is shown as including the motor 13 and various integral mounting features, such as reinforcing ribs 15 , and mounting flanges 17 . In accordance with the present invention, the blower would be conductive, in order that a mild current could be applied to cause a resistance and induce heating in the blower itself. Thus, the need for the heating coils 16 would be entirely eliminated making the furnace much more cost efficient, and smaller.
[0024] Sheet molding and bulk molding compositions are described in U.S. Pat. Nos. 5,998,510; 5,342,554; 5,854,317; 5,744,816; and 5,268,400; all of which are hereby incorporated by reference for their teachings on the various modifications to molding compositions that are known to the art.
[0025] One component of the molding resin composition is a cross linkable prepolymer such as an unsaturated polyester resin or vinyl ester resin. Desirably the prepolymer has a relatively low molecular weight such as from about 200 to about 5000 (weight average) and a glass transition temperature from about 320° F. (160° C.) to about 343° F. (173° C.). They are described in detail with examples in the above patents incorporated by reference. The polyester resins are the condensation product derived from the condensation of unsaturated polybasic acids and/or anhydrides with polyols such as dihydroxy or trihydroxy compounds. Desirably, these polyester resins are the esterification reaction product of diacids, or anhydrides of diacids, generally having from about 3 to about 12, or more preferably from about 4 to about 8 carbon atoms, with a polyol or a cyclic ether having from about 2 to about 12, or more preferably from about 2 to about 6 carbon atoms.
[0026] In general, the vinyl ester resins that can be used are the reaction products of epoxy resins and a monofunctional ethlenically unsaturated carboxylic acid. More specifically, these vinyl ester resins are the reaction product of an epoxy terminated oligomer, for example, an epoxy functionalized bisphenol A with an acrylic acid, or methacrylic acid forming acrylic terminal groups on the oligomer. The vinyl esters have predominantly terminal unsaturation while the unsaturated polyesters have predominantly internal unsaturation.
[0027] Another component of the molding composition is one or more unsaturated monomer that is copolymerizable with the resin. Desirably, this component is capable of dissolving the resin component at room temperature. Thus, in one embodiment the resin is dissolved in the monomeric component prior to being combined with the remaining components. Examples of suitable monomers are styrene, alpha-methyl styrene, chloro-styrene, vinyl toluene, divinyl benzene, diallylphthalate, methyl methacrylate, and mixture of these, with preferred monomers being styrene and methyl methacrylate. The ratio of monomer(s) to resin is desirably from about 5:95 to about 50:50 and preferably from about 10:90 to about 25:75 by weight.
[0028] Another component to the molding composition is fillers. In accordance with the invention the predominant filler is a conductive filler in order to impart electrical conductivity of the final molded product. A preferred filler is graphite particles. Suitable graphite particles include both natural and synthetic graphite.
[0029] Particles are typically measured in microns at some diameter, or also by mesh size wherein a suitable mesh here is typically mostly smaller than about 60 mesh. In addition, silver coated ceramic fibers can be added to improve the overall electrical properties.
[0030] In particular, a synthetic crystalline graphite particle, such as currently supplied by applied Carbon of New Jersey under the trademark K100 and K112. The first is characterized as having 0.7 at 40 mesh (420 microns), 22% at 50 mesh (297 microns), 22% at 60 mesh (250 microns), 19% at 70 mesh (210 microns), 16% at 80 mesh (177 microns), 17% at 100 mesh (149 microns), and 2% at 200 mesh (74 microns). The second is characterized in having 0.5% at 40 mesh (420 microns), 18% at 50 mesh (297 microns), 15% at 60 mesh (250 microns), 12% at 70 mesh (210 microns), 9% at 80 mesh (177 microns), 9% at 100 mesh (149 microns), 23% at 200 mesh (74 microns), 9% at 325 mesh (44 microns) and 5% at −325 mesh (where the negative size indicates that the particulate is smaller than this mesh). Other graphites are sold by Asbury Graphite in Asbury, N.J. under the designations Asbury 4172 and 4811. This first graphite is characterized as having 55% at 50 mesh (297 microns), 22% at 60 mesh (250 microns), 16% at 70 mesh (210 microns), and 6% at 80 mesh (177 microns). The second graphite is characterized as having 36% at 100 mesh (149 microns), 45% at 200 mesh (74 microns), 12% at 325 mesh (44 microns), and 8% at −325 mesh (the negative sign denotes particles smaller than the designated mesh). Other graphite fillers might be used instead of or in addition to the preferred graphites, and include: Ashbury A99, Ashbury 3243, Ashbury modified 4012, Ashbury 3285, Ashbury 230U; Timrex® KS 75 and 150, and Timrex® KC 44, all sold by TIMCAL of Westlake, Ohio; and Calgraph Sold by SGL Technic Inc of Valencia, Calif. This filler is used at a loading of at least 10% by weight. Other conductive fillers such as other forms of graphite (including graphite pitch-based fibers), conductive polymer metal particles, or metal coat particles may be used in conjunction with the graphite filler. Desirably conductive fillers are at least about 10, about 20, or about 25 weight percent of the molding composition and up to 50 weight percent. Alternatively this amount can be expressed as at least about 10 phr, more preferably at least about 25, or 50 phr or even over 100 phr. Alternatively stated the conductive fillers are present in an effective amount to result in a bulk conductivity of at least about 1 to 25 ohms when measured as described in the examples for a 6″ by 6″ molded plaque having a thickness of about 0.125 inches. If necessary for a particular application these values can be increased by the addition of conductive enhancers such as silver coated ceramic fibers, like Ag-Fiber sold by Energy Strategy Associates of Florida, or conductive polymers such as poly-paraphenyleneimine based products sold under the Tyrosid 1000 designation by J. H. Hinz Company of Westlake, Ohio.
[0031] An initiator is another component of the molding composition. The initiator initiates the copolymerization of the resin and the monomer(s). Initiators include any free radical initiator capable of forming radicals in the correct concentration under the molding conditions. They may include peroxides, hydroperoxides, redox systems, diazo compounds, persulfates, perbenzoates etc. The initiators are typically used in amounts of about 0.05 to about 5 weight percent, and more preferably about 0.1 to about 2 weight percent. Alternatively, these amount can be expressed in parts per hundred parts by weight of resin, i.e. from about 0.5 to about 4.0 phr, preferably from about 0.7 to about 3.0 phr, and most preferably from about 0.8 to about 2.25 phr. Alternatively high temperature initiators such as Di-cup, e.g. dicumyl peroxide can be used for molding applications where higher initiation temperatures are desirable. Peroxy initiators are preferred.
[0032] The inclusion of 0.5 to 10 phr, preferably about 1 to 8 phr, of a mold release agent, such as Tech-lube HV706, calcium stearate, zinc stearate, or the like may also be of advantage to achieving without machining the complex molded part of the present invention. Tech-lube HV706 is proprietary composition of fatty acids, glycerides, polymeric resin and phosphate surfactant sold by Tech-nick Products of New Jersey. A viscosity reducer can be used in combination with styrene to maintain the molding properties, and the decrease the cost of the composition.
[0033] Another optional component to the improved molding composition is a rheological modifier, which may act to increase the molecular weight such as by chain extension of the resin prepolymer. Suitable modifiers include Group II oxides and hydroxides, such as calcium or magnesium oxide. These modifiers may act to reduce shear and thus promote flow in the composition during molding. Fumed silica is an example of a substance, which may act mechanically to increase molding viscosity and therefore also be a suitable rheological modifier either alone or in combination with the previously mentioned ingredients.
[0034] Desirably the rheological modifiers are used in an effective amount to enhance molding properties, such as thickening the resin system prior to molding. Desirable amounts of group II oxides (including group II hydroxides and mixtures of these compounds) is from about 0.1 to about 1 or about 2 weight percent, more desirably from about 0.2 or about 0.3 to about 0.7 or about 0.8 weight percent. This can also be expressed as from about 0.5 to about 4.0 phr, preferably from about 1.0 to about 3.0 phr, and most preferably from about 1.5 to about 2.5 phr. Specific preferred compounds include magnesium oxide, or magnesium hydroxide or calcium oxide. An example of a suitable magnesium oxide additive is 99% pure magnesium oxide sold under the trade name “Elastomag” from Morton Thiokol, Inc. in Danvers, Mass. Other examples include a magnesium oxide dispersion sold under the trade name “PG-9033” by Plasticolors, and a magnesium hydroxide dispersion also sold by Plasticolors under the trade name “PG-91146”. Another suitable magnesium hydroxide is Barcroft, which is a powdered version. Fumed silica could be used at from about 0.5 to about 20 phr, preferably from about 1 to 10 phr.
[0035] Other components to the conductive molding composition include flame retardants such as decabromo flame retardants for example one sold under the tradename FR-1210 by Durr Marketing, used in the range of from about 5 to about 20 phr, and more preferably in the range of from about 7.5 to about 15 phr, and most preferably in the range of about 10 to about 15 phr. This can advantageously be combined with a synergist such as antimony trioxide such as SB203 sold by Durr Marketing and used in the range of from about 0.5 to about 10 phr, and preferably from about 1 to about 7.5 phr, and more preferably from about 3 to about 6 phr.
[0036] The composition also includes fibrous reinforcing agents such as cotton glass microfibers or graphite microfibers; flexibilizing agents; mold release agents; polymerization inhibitors to inhibit premature polymerization during storage or the initial stages of molding; viscosity modifiers like fumed silica; and mold lubricant like stearates of calcium, zinc or magnesium. The fibers may comprise chopped sized glass microfiber rovings at an amount below 20% for sound dampening, and preferably from about 10 to about 20%, and more preferably from about 15 to about 20% in particular for the combination blower housing/heater. The fibers are chopped to from about ⅛ to about ½ inch for BMC, to about ¼ to about 2 inches for SMC, and from about ¼ to about 1 inch for TMC. Carbon black may be added to influence the surface conductivity and to change the appearance of the molded product. Suitable carbon blacks include an electrically conductive low residue carbon black having a nitrogen surface area m2/g of 270, a STSA surface Area m2/g of 145 a sieve residue at 35 mesh of 0 ppm and at 325 mesh of 20 ppm as sold under the trade name Conductex 975 by Columbia Chemicals of Jamesburg, N.J. Also, suitable conductive carbon black is supplied by Akzo Nobel Chemicals of Chicago, Ill. under the trade name Ketjenblack EC-300 J and EC-600JD. Cabot Corporation of Boston, Mass. and Applied Science of Cedarville, Ohio supply conductive carbon blacks. It is noted that polyethylene and fumed silica can function as the rheological modifier in addition to the foregoing functions.
[0037] In addition, shrink control additives can advantageously be added to improve the surface characteristics and the dimensional stability of the resulting products. These shrink control additives include “anti-shrink” and “low profile additives” as part of this aspect of the invention. These additives generally include thermoplastics or elastomerics such as homopolymers of ethylene, styrene, vinyl toluene, alkyl methacrylates, polyethylene ether, polyphenylene oxide and alkyl acrylates. Additional examples include copolymers using the foregoing and in addition, vinyl chloride, vinyl acetate, acrylonitrile, and butadiene. In particular these co-polymers would advantageously include copolymers of vinyl chloride and vinyl acetate; styrene and acrylonitrile; methyl methacrylate and alkyl esters of acrylic acid; methyl methacrylate and styrene; methyl methacrylate and acrylamide; and SBS block copolymers. Particularly advantageous additives are thermoplastics, with saturated polyesters being preferred among these. These additives are generally used in the range of 10 to 50 weight percent based on the total weight of the additive and the resin system, i.e. the resin and any monomers. More preferably this range would be 20 to 45 weight percent, with a particularly preferred range of about 30 to 40 weight percent. These additives are usually added with the resin blending. As necessary the cure system may be adjusted to compensate for the presence of the additive.
[0038] The molding compositions may be formulated and mixed using a variety of mixing conditions including either continuous or batch and using a variety of known mixing equipment. Specific examples are set forth in the example section. The compositions may be advantageously stored for reasonable times before molding. The compositions can be molded by a variety of methods including compression, transfer, and injection molding or combinations of theses techniques. The compositions can be molded under typical conditions for these types of molding including at pressures from about 400 to about 9000 psi, and preferably from about 2000 to about 3500 psi, and most preferably from about 2500 to about 3000 psi and temperatures at from about 225 to about 400 degrees Fahrenheit. Dwell times are from about 10 seconds to about four minutes.
[0039] Otherwise conventional injection molding techniques apply as is discussed for example in U.S. Pat. No. 6,365,069 B2 incorporated by reference herein. It is preferable to avoid temperature variations at the mold level. At normal cure rates, the mold time for injection molding is typically around 5 to 600 seconds, or more usually 30 to 300 seconds or around one or two minutes. The process can be practiced for single or double gate cavity tools, or even for injection/compression processes in which the mold is slightly opened during fill and the mold is shut to compress the shot.
[0040] The articles from the composition desirably have tensile strength from about 2000 to about 6000 psi as measured in accordance with ASTM test No. D638 and flexural modulus from about 3000 to about 10,000 psi when tested in accordance with ASTM test no. D790.
[0041] Molded products made from the compositions of the present invention are useful for a variety of applications demanding complex configurations, conductivity, as well as strength, and corrosion resistance. One particularly advantageous product, which can be made by compression molding, is a combination heater blower housing shown in FIG. 1 . This housing combines the function of a heater with the blower housing of the prior art. The housing is typically molded in two parts and fitted together.
[0042] The following compositions are examples of ingredients that could be used in the composition of the present composition: Suitable resins may include, but not be limited to the following: Hetron 922 is available from Ashland Chemical Co in Columbus, Ohio. It is a low viscosity epoxy vinyl ester resin. It is about 55 wt. % solids and about 45 wt. % reactive monomer. Atlac 382ES is a resin from Reichhold Chemicals, Inc. in Research Triangle Park, N.C. It is characterized as a bisphenol fumarate resin. It is diluted to about 55 wt. % solids with styrene. Dion 6694 is a resin diluted to 55 wt. % solids in styrene. It is available from Reichhold Chemicals, Inc. It is characterized as a modified bisphenol fumarate polyester. Resin 42-2641 is available from Cook Composites and Polymers in Kansas City, Mo. It is diluted to 55 wt. % solids with styrene. It is characterized as an unsaturated polyester resin. ATLAC 3581-61 is sold by Reichhold Chemicals, Inc. It is characterized as a vinyl ester resin at 19 wt %, polyester at 27 wt % and urethane polymer at 4 wt % combined with 50 wt % styrene. Thus, it is diluted to 50 wt % solids with styrene. 580-05 is a resin from Reichhold Chemicals, Inc. It is characterized as a urethane-modified vinyl ester resin. It is diluted to 54 wt % solids with styrene. 9100 is a resin from Reichhold Chemicals, Inc. It is characterized as a bisphenol-epoxy vinyl ester. It is diluted to 54-58 wt % solids with styrene. Dow Derakane R8084 from Dow Chemicals, Inc. It is characterized as an elastomer-modified vinyl ester resin. It is diluted to 50-60 wt % solids with styrene. 9480-00 from is from Reichhold Chemicals, Inc. It is characterized as an epoxy novolac vinyl ester. It is diluted to 53.5 wt % solids with styrene. 31632 is from Reichhold Chemicals, Inc. It is characterized as a isocyanurate vinyl ester resin with 4 wt % polyether polyol. It is diluted to 60 wt % solids with styrene. Dow Derakane 797 from Dow Chemicals, Inc. It is characterized as a one pack resin which is an epoxy vinyl ester resin containing 7-13 weight percent of divinyl benzene, 5-15 weight percent of styrene butadiene rubber co-polymer, 2-6 weight percent of styrene homopolymer, and 0.5 to 1.5 weight percent of styrene-ethylene oxide block copolymer, as a low profile additive. It is diluted to 60-65 wt % solids with styrene. Dow Derakane 790 from Dow Chemicals, Inc. It is also characterized as a one pack resin which is an epoxy vinyl ester resin containing 5-15 weight percent of styrene butadiene rubber co-polymer, 2-6 weight percent of styrene homopolymer, and 0.5 to 1.5 weight percent of styrene-ethylene oxide block copolymer, as a low profile additive. It is diluted to 50-60 wt % solids with styrene. 31633-00 from Reichhold Chemicals, Inc. It is characterized as a isocyanurate vinyl ester resin with 4 wt % polyether polyol. It is diluted to 60 wt % solids with styrene. Derakane 780 is from Dow Chemicals, Inc. It is also characterized as a vinyl ester resin. It is diluted to 60-70 wt % solids with styrene. Polylite is from Reichhold Chemicals, Inc. Altac-G380 is from Reichhold Chemicals, Inc. Derakane 790 is from Dow Chemicals, Inc.
[0043] These resins can be combined with monomers, such as styrene, or Divinylbenzene HP from the Dow Chemical Company and characterized as 80 wt % benzene, 18 wt % ethylvinylbenzene, less than 0.12 wt % p-tert butylcatechol, less than 0.5 wt % diethylbenzene and less than 1 wt % of Naphthalene.
[0044] In addition, rheological modifiers can be used and include Elastomag from Morton Thiokol. Inc. in Danvers, Mass. It is characterized as 99% pure magnesium oxide The modifiers could also include FN-510, a linear low-density polyethylene from Equistar Chemicals, L.P. of Houston, Tex. and fumed silica, such as Cab-o-sil silica.
[0045] Suitable initiators include Vazo (2,2-azo bisisobutyronitrile) available from Dupont, I & B Industrial and Biochemical Dept, Wilmington Del., tert-butyl peroxy isopropyl carbonate (Triginox BPIC) available from Durr Marketing in Pittsburgh, Pa., t-butylperbenzoate (TBPB) available from Durr Marketing, and 1,3 di-t-butyl peroxy-3,5,5 trimethylcyclohexane catalyst (Trig 29B75) available from Durr Marketing.
[0046] Calcium stearate and zinc stearate sold as COAD 27 by the Norac Company, Incorporated of Azusa, Calif. can be used as mold release agents, as can Tech-Lube HV-706, which is a proprietary composition of fatty acids, glycerides, polymeric resin and phosphate surfactant.
[0047] Suitable graphite products include graphite 4012 available from Asbury Graphite in Asbury, N.J. It is characterized by having less than 10% greater than 150 microns and less than 10% smaller than 44 microns in diameter; SGL Ash02 characterized as a natural graphite flake product sold by SGL Corporation; XC-72.SGLV Fine characterized as a natural graphite flake product sold by SGL Corporation; conductive graphite flake available from Asbury Graphite in Asbury, N.J. under the trade designation 3243 and characterized by having less than 18% greater than 75 microns and less than 65% smaller than 44 microns in diameter; conductive flake graphite available from Asbury Graphite in Asbury, N.J. under the trade designation 230U and characterized by having 100% smaller than 44 microns in diameter; a synthetic graphite available from Asbury Graphite in Asbury, N.J. under the trade designation A99 and characterized by having less than 3% greater than 44 microns and less than 99% smaller than 44 microns in diameter; a synthetic graphite available under the designation KS 75, from Timrex America, Inc. and characterized by having less than 95% greater than 96 microns and less than 95% smaller than 75 microns in diameter; a synthetic graphite available under the designation KS 150, from Timrex America, Inc. and characterized by having at least 95% less than 180 microns in diameter; a synthetic graphite available under the designation KC44, from Timrex America, Inc. and characterized by having at least 90% less than 48 microns in diameter; a graphite available under the designation Timrex KS5-75TT from TimCal Ltd. of Bodio, Switzerland and characterized as having a particle distribution with d10 of 9.1 μm, a d50 of 38.8 μm, and a d90 of 70 μm, as determined by laser diffraction (Malvern); a synthetic graphite available under the designation of K103 from Applied Carbon Technology and having a particle size distribution characterized as 1.0% max at +80 mesh, 10.% max at 100 mesh and 10.0% max at −325 mesh; a graphite available under the designation Graphco from Asbury Graphite Mills having a particle size distribution characterized as 0.34% at +30 mesh, 58.9% at +50 mesh, 25.2% at +60 mesh, 10.9% at +80 mesh, and 5.7% at −80 mesh; a graphite available under the designation Graphite Sales FP143 or ElCarbo100 from Graphite Sales of Nova, Ohio and having a particle size distribution characterized as 5% at 2 mm, 30% at 0.8 mm, 50% at 0.2 mm, and 10% at pan; a graphite available under the designation Asbury T SO333 from Asbury Graphite Mills and characterized as having a particle distribution of 0.17% at screen 100; 54.90% at screen 200; 30.5% at screen 325, and a pan of 14.43%; a graphite available under the designation Asbury 4461 from Asbury Graphite Mills and characterized as having a particle distribution of 0.05% at +60 mesh; 35.52% of +100 mesh; 44.82% at +200 mesh; 11.77% at +325 mesh, and 7.9% at −325 mesh; a graphite available under the designation Asbury 3285 from Asbury Graphite Mills and characterized as having a particle distribution of 0.05% at +100 mesh; 10.46% at +200 mesh; 29.22% at +325 mesh, and 60.32% at −325 mesh; a graphite available under the designation Asbury 4592 from Asbury Graphite Mills and characterized as having a particle distribution of 0.02% at +60 mesh; 0.04% at +80 mesh; 0.78% at +100 mesh; 96.12% at +200 mesh; 1.3% at +325 mesh, and 1.74% at −325 mesh; a graphite available under the designation Asbury 4172 from Asbury Graphite Mills and characterized as having a particle distribution of 0.34% at +30 mesh; 54.87% at +50 mesh; 21.52% at +60 mesh; 16.19% at +70 mesh; 5.7% at +80 mesh; 1.38% at −80 mesh, and 1.45% at −200 mesh; a graphite available under the designation Asbury 4811 from Asbury Graphite Mills and characterized as having a particle distribution of 0.05% at +60 mesh; 35.52% at +100 mesh; 44.82% at +200 mesh; 11.77% at +325 mesh, and 7.9% at −325 mesh; a synthetic graphite available under the designation K100 from Applied Carbon Technology of Sommerville, N.J. and characterized as having a typical particle distribution of 0.18% at +30 mesh; 0.51-0.69% at +40 mesh; 22.16-24.98% at +50 mesh; 19.51% -22.17% at +60 mesh; 17.98%-19.77% at +70 mesh; 15.05% -15.84% at +80 mesh; 14.04%-17.84% at +100 mesh; 3.38%-5.62% at +200 mesh; 0.03% at +325 mesh, and 0.15% -0.50% at −325 mesh; a graphite available under the designation K112 from Applied Carbon Technology and characterized as having a typical particle distribution of 0.14% at +30 mesh; 0.48% at +40 mesh; 17.62% at +50 mesh; 14.53% at +60 mesh; 12.05% at +70 mesh; 9.47% at +80 mesh; 8.89% at +100 mesh; 23.12% at +200 mesh; 8.87% +325 mesh, and 4.83% at −325 mesh; and a graphite available under the designation Asbury 4580 from Asbury Graphite Mills and characterized as having a typical particle distribution of 0.05% at +10 mesh; 11.92% at +20 mesh; 62.33% at +30 mesh, and 25.64 at −30 mesh.
[0048] Carbon blacks can be used and include is a conductive carbon black nano fiber supplied under the trade name Pyrograph Applied Sciences, Inc. of Cedarville, Ohio; an electrically conductive low residue carbon black having a nitrogen surface area m2/g of 270, a STSA surface Area m2/g of 145 a sieve residue at 35 mesh of 0 ppm and at 325 mesh of 20 ppm as sold under the trade name Conductex 975 by Columbia Chemicals of Jamesburg, N.J.; conductive carbon black supplied by Cabot Corporation of Boston, Mass. under the trade name, Black Pearls; conductive carbon black supplied by Akzo Nobel Chemicals of Chicago, Ill. under the trade name Ketjenblack EC-300 J and EC-600JD. EC-300 J has an iodine absorption of 740-840 mg/g; a pore volume of 310-345 cm3/100 g and an apparent bulk density of 125-145 kg/m3. EC-600 JD has an iodine absorption of 1000-1150 mg/g; a pore volume of 480-510 cm3/100 g and an apparent bulk density of 100-120 kg/m3.
EXAMPLES
[0049] The following examples use the components set forth below.
[0050] Resin A is 31009 terephatic resin sold by Reichhold.
[0051] Resin B is Dow Derakane 780 from Dow Chemicals, Inc. It is also characterized as a epoxy novalac vinyl ester resin. It was diluted to 60-70 wt % solids with styrene.
[0052] Resin C is Q-8000 is a saturated polyester from Ashland Chemical.
[0053] Monomer A is styrene.
[0000] These ingredients are added together to comprise the base resin for 100 phr.
[0054] Flame retardant A is FR-121-(DBDPO)
[0055] Synergist A is Antimony Trioxide
[0056] Flow modifier A is FN-510, a linear low-density polyethylene from Equistar Chemicals, L.P. of Houston, Tex.
[0057] Initiator A is tert-Amyl peroxy-2-ethylhexanoate in a diluent of odorless mineral spirits, which is used as a catalyst (Trig 121C-75) available from Durr Marketing.
[0058] Initiator B is tert-butyl peroxy isopropyl carbonate (Triginox BPIC) available from Durr Marketing in Pittsburgh, PA.
[0059] Inhibitor A is 91029 is BHT from Plasticolors.
[0060] Inhibitor B is 9139 is PBQ from Plasticolors.
[0061] Viscosity reducer A is BY-W-996 from BYK Chemie.
[0062] Mold release agent A is calcium stearate from Norac.
[0063] Graphite A is a synthetic graphite available under the designation K100 from Applied Carbon Technology of Sommerville, N.J. It is characterized as having a typical particle distribution of 0.18% at +30 mesh; 0.51-0.69% at +40 mesh; 22.16-24.98% at +50 mesh; 19.51%-22.17% at +60 mesh; 17.98% -19.77% at +70 mesh; 15.05% -15.84% at +80 mesh; 14.04% -17.84% at +100 mesh; 3.38% -5.62% at +200 mesh; 0.03% at +325 mesh, and 0.15% -0.50% at −325 mesh.
[0064] Graphite B is graphite 4012 available from Asbury Graphite in Asbury, N.J. It is characterized by having less than 10% greater than 150 microns and less than 10% smaller than 44 microns in diameter.
[0065] Thickener A is PG-9033P is a mag oxide dispersion from Plasticolors.
[0066] Glass fibers used are 973C-AB-113. The Glass fibers were from Owens-Corning Fiberglass and are characterized as continuous glass filaments hammer milled into a specific length used as a reinforcing and filler medium.
[0067] The molding compositions are generally prepared by adding the resin, monomer, initiator, inhibitor, mold release agent, and rheological modifier (if present) to a high shear cowls disperser and blending for 2 minutes at approximately 3,200 rpm. The conductive filler is added to the mix in a Baker Perkin, or Littleford continuous mixer and mixed 10 to 15 minutes. A Readco mixer can also be used and the ingredients can be ported in separately or added at the same time under cowls. When mixing is complete the composition is put in a suitable barrier bag and allowed to mature for approximately one day before molding.
[0068] The molding parameters for the molding compositions are as follows: General molding temperatures for 12″×12″ plaques at 0.125 inch was 280° F. up to 370° F. with a molding time of 3 minutes down to 108 seconds depending on the initiator and a charge weight of from 450 to 500 g. Preferably, the molding temperature for plaques was 310° F. with a molding time of about two minutes and a charge weight of 500 g.
[0069] The following procedure was used as an SMC pilot paste preparation for SL-790-Z6 compound as an example procedure:
[0070] The resin components were added to a 5 gallon pail with the initiator and the first of the inhibitor and blended under a Cowels disperser at approximately 3,200 rpm and then half of the graphite was slowly added, and then the flame retardants were added with continued blending. The thickener was slowly added and the remainder of the graphite and the mix was blended to a temperature of 110° F. Prior to running on a SMC machine, the thickener as added and the mix was blended for 2 minutes. The SMC machine 300 shown in FIG. 8 was started and run at a rate of 6 meters per minute. Equal parts of the paste 302 was transferred to SMC machine doctor boxes 304 . Glass rovings 306 were fed onto a carrier film 308 with the resin from chopper blades 310 . The glass chopper 310 was started when the poly with the paste deposited on it reached the chopper zone. After the glass was deposited it then meets the paste and poly from the upper doctor box where the two components go through a compaction zone 312 to get sandwiched between two carrier films 308 to wet out the glass fibers. The thickness was measured using a gamma gauge 314 . The resulting compound was wound onto a cardboard core and packaged in a box for later use. This was molded into test panels and also into prototype heater/blower housings.
SL-790- SL-790- INGREDIENTS SL-790-X2 X2 PHR SL-790-X3 X3 PHR SL-790-X4 SL-790-X4 PHR SL-790-Y9 SL-790-Y9 PHR 31009 18.53 46.01 16.33 43.82 17.53 43.53 18.19 45.17 780 6.59 16.36 6.02 16.15 5.59 13.88 6.26 15.55 Q-8000 11.4 28.31 10.17 27.29 9.4 23.34 11.07 27.49 HP-DVB STYRENE 3.75 9.31 4.75 12.74 7.75 19.25 4.75 11.80 PHR CHECK 100.00 100.00 100.00 100.00 FR-1210(DBDPO) SB203 Antimony Trioxide FN-510 1.04 2.58 1.04 2.79 1.04 2.58 1.04 2.58 TRIG 12IC-75 0.18 0.45 0.18 0.48 0.18 0.45 0.18 0.45 TRIG BPIC 0.18 0.45 0.18 0.48 0.18 0.45 0.18 0.45 IN-91029 0.1 0.25 0.1 0.27 0.1 0.25 0.1 0.25 IN-9139 0.18 0.45 0.18 0.48 0.18 0.45 0.18 0.45 BYK-W-996 0.8 1.99 0.8 2.15 0.8 1.99 0.8 1.99 CAST 1.5 3.72 1.5 4.02 1.5 3.72 1.5 3.72 K-100 GRAPHITE 40 99.33 45 120.74 20 49.66 4012 GRAPHITE 40 99.33 20 49.66 PG-9033P 0.75 1.86 0.75 2.01 0.75 1.86 0.75 1.86 973C-AB-113 15 37.25 15 40.25 15 37.25 15 37.25 PHR COND. MEDIA 99.33 120.74 99.33 99.33 PHR NON-COND. MEDIA 148.99 152.94 148.99 148.99 ohms (plaques) 0.68 0.42 5.5 1.6 ohms (Actual Housing) SL-790- SL-790- INGREDIENTS SL-790-Z1 Z1 PHR SL-790-Z2 Z2 PHR SL-790-Z3 SL-790-Z3 PHR SL-790-Z4 SL-790-Z4 PHR 31009 18.19 45.17 15.69 45.78 15.69 45.78 13.75 43.97 780 6.26 15.55 5.26 15.35 5.26 15.35 4.4 14.07 Q-8000 11.07 27.49 8.57 25.01 8.57 25.01 7.37 23.57 HP-DVB STYRENE 4.75 11.80 4.75 13.86 4.75 13.86 5.75 18.39 PHR CHECK 100.00 100.00 100.00 100.00 FR-1210(DBDPO) 4 11.67 4 11.67 4 12.79 SB203 Antimony Trioxide 2 5.84 2 5.84 2 6.40 FN-510 1.04 2.58 1.04 3.03 1.04 3.03 1.04 3.33 TRIG 121C-75 0.18 0.45 0.18 0.53 0.18 0.53 0.18 0.58 TRIG BPIC 0.18 0.45 0.18 0.53 0.18 0.53 0.18 0.58 IN-91029 0.1 0.25 0.1 0.29 0.1 0.29 0.1 0.32 IN-9139 0.18 0.45 0.18 0.53 0.18 0.53 0.18 0.58 BYK-W-996 0.8 1.99 0.8 2.33 0.8 2.33 0.8 2.56 CAST 1.5 3.72 1.5 4.38 1.5 4.38 1.5 4.80 K-100 GRAPHITE 15 37.25 20 58.36 15 43.77 43 137.51 4012 GRAPHITE 25 62.08 20 58.36 25 72.95 PG-9033P 0.75 1.86 0.75 2.19 0.75 2.19 0.75 2.40 973C-AB-113 15 37.25 15 43.77 15 43.77 15 47.97 PHR COND. MEDIA 99.33 116.72 116.72 137.51 PHR NON-COND. MEDIA 148.99 175.08 175.08 182.28 ohms (plaques) 1.84 4.25 ohms (Actual Housing) SL-791- SL-791- INGREDIENTS SL-791-A6 A6 PHR SL-791-A7 A7 PHR SL-791-A8 SL-791-A8 PHR SL-791-A9 SL-791-A9 PHR 31009 17.34 44.27 16.34 45.18 14.18 41.50 14.52 42.49 780 6.91 17.64 5.91 16.34 5.08 14.87 5.41 15.83 Q-8000 10.22 26.09 9.22 25.49 8.21 24.03 8.54 24.99 HP-DVB STYRENE 4.7 12.00 4.7 12.99 6.7 19.61 5.7 16.68 PHR CHECK 100.00 100.00 100.00 100.00 FR 1210(DBDPO) 4 10.21 4 11.06 4 11.71 4 11.71 SB203 Antimony Trioxide 2 5.11 2 5.53 2 5.85 2 5.85 FN-510 1.04 2.66 1.04 2.88 1.04 3.04 1.04 3.04 TRIG 121C-75 0.18 0.46 0.18 0.50 0.18 0.53 0.18 0.53 TRIG BPIC 0.18 0.46 0.18 0.50 0.18 0.53 0.18 0.53 IN-91029 0.1 0.26 0.1 0.28 0.1 0.29 0.1 0.29 IN-9139 0.18 0.46 0.18 0.50 0.18 0.53 0.18 0.53 BYK-W-996 0.8 2.04 0.8 2.21 0.8 2.34 0.8 2.34 CAST 1.5 3.83 1.5 4.15 1.5 4.39 1.5 4.39 K-100 GRAPHITE 4012 GRAPHITE 35 89.35 35 96.77 37 108.28 35 102.43 PG-9033P 0.85 2.17 0.85 2.35 0.85 2.49 0.85 2.49 973C-AB-113 15 38.29 18 49.76 18 52.68 20 58.53 PHR COND. MEDIA 89.35 96.77 108.28 102.43 PHR NON-COND. MEDIA 165.94 179.71 184.37 190.23 ohms (plaques) 3.9 ohms (Actual Housing) 1.6 HI TEMP SL-791- SL-791- SL-791- HI TEMP SL-791- HI TEMP INGREDIENTS SL-791-B5 B5 PHR SL-791-B6 B6 PHR SL-791-B7 B7 PHR SL-791-C6 C6 PHR SL-791-G1 31009 17.34 44.27 15.52 41.75 16.34 45.18 17.61 44.06 17.95 780 6.91 17.64 6.41 17.25 5.91 16.34 7.18 17.96 7.51 Q-8000 10.22 26.09 9.54 25.67 9.22 25.49 10.48 26.22 10.81 HP-DVB 2.5 5.50 2.5 STYRENE 4.7 12.00 5.7 15.33 4.7 12.99 2.2 6.26 2.2 PHR CHECK 100.00 100.00 100.00 100.00 FR-1210(DBDPO) 5 12.76 5 13.45 5 13.82 5 12.51 5 SB203 Antimony Trioxide 3 7.66 3 8.07 3 8.29 3 7.51 3 FN-510 1.04 2.66 1.04 2.80 1.04 2.88 1.04 2.60 1.04 TRIG 121C-75 0.18 0.46 0.18 0.48 0.18 0.50 0.18 0.45 0.18 TRIG BPIC 0.18 0.46 0.18 0.48 0.18 0.50 0.18 0.45 0.18 IN-91029 0.1 0.26 0.1 0.27 0.1 0.28 0.1 0.25 0.1 IN-9139 0.18 0.46 0.18 0.48 0.18 0.50 0.18 0.45 0.18 BYK-W-996 0.8 2.04 0.8 2.15 0.8 2.21 CAST 1.5 3.83 1.5 4.04 1.5 4.15 1.5 3.75 1.5 K-100 GRAPHITE 4012 GRAPHITE 30 76.59 30 80.71 36 99.53 30 75.06 25 PG-9033P 0.85 2.17 0.85 2.29 0.85 2.35 0.85 2.13 0.85 973C-AB-113 18 45.95 20 53.81 15 41.47 18 45.03 22 PHR COND. MEDIA 76.59 80.71 99.53 75.06 PHR NON COND. MEDIA 178.71 188.32 176.94 175.13 ohms (plaques) 22.7 9.65 8.8 21 ohms (Actual Housing) 3.9 4.5 SL-790- SL-790- INGREDIENTS SL-790-Z5 Z5 PHR SL-790-Z6 Z6 PHR SL-791 A4 SL-791-A4 PHR SL-791 A5 SL-791-A5 PHR 31009 15.69 45.78 15.69 45.78 15.02 43.89 15.02 43.89 780 5.26 15.35 5.26 15.35 4.6 13.44 4.6 13.44 Q-8000 8.57 25.01 8.57 25.01 7.9 23.09 7.9 23.09 HP-DVB STYRENE 4.75 13.86 4.75 13.86 6.7 19.58 6.7 19.58 PHR CHECK 100.00 100.00 100.00 100.00 FR-1210(DBDPO) 4 11.67 4 11.67 4 11.69 4 11.69 SB203 Antimony Trioxide 2 5.84 2 5.84 2 5.84 2 5.84 FN-510 1.04 3.03 1.04 3.03 1.04 3.04 1.04 3.04 TRIG 121C-75 0.18 0.53 0.18 0.53 0.18 0.53 0.18 0.53 TRIG BPIC 0.18 0.53 0.18 0.53 0.18 0.53 0.18 0.53 IN-91029 0.1 0.29 0.1 0.29 0.1 0.29 0.1 0.29 IN-9139 0.18 0.53 0.18 0.53 0.18 0.53 0.18 0.53 BYK-W-996 0.8 2.33 0.8 2.33 0.8 2.34 0.8 2.34 CAST 1.5 4.38 1.5 4.38 1.5 4.38 1.5 4.38 K-100 GRAPHITE 40 116.72 35 102.13 5 14.61 4012 GRAPHITE 5 14.59 35 102.28 40 116.89 PG-9033P 0.75 2.19 0.76 2.19 0.8 2.34 0.8 2.34 973C-AB-113 15 43.77 15 43.77 15 43.83 15 43.83 PHR COND. MEDIA 116.72 116.72 116.89 116.89 PHR NON-COND. MEDIA 175.08 175.08 175.34 175.34 ohms (plaques) 2.04 6.9 ohms (Actual Housing) 1 3.2 HI TEMP HI TEMP HI TEMP INGREDIENTS SL-791-G1 PHR SL-791-G2 SL-791-G2 PHR 31009 48.81 18.62 43.33 780 18.33 8.18 19.04 Q-8000 26.39 11.47 26.69 HP-DVB 6.10 2.5 5.82 STYRENE 5.37 2.2 5.12 PHR CHECK 100.00 100.00 FR-1210(DBDPO) 12.20 5 11.64 SB203 Antimony Trioxide 7.32 3 6.98 FN-510 2.53 1.04 2.42 TRIG 12IC-75 0.44 0.18 0.42 TRIG BPIC 0.44 0.18 0.42 IN-91029 0.24 0.1 0.23 IN-9139 0.44 0.18 0.42 BYK-W-996 CAST 3.66 1.5 3.49 K-100 GRAPHITE 4012 GRAPHITE 61.02 20 46.54 PG-9033P 2.07 0.85 1.98 973C-AB-113 53.70 25 58.18 PHR COND. MEDIA 61.02 46.54 PHR NON-COND. MEDIA 183.04 186.18 ohms (plaques) ohms (Actual Housing)
[0071] FIG. 3 is a graph of the sound speed versus temperature for a resin composition testing various loadings of glass fibers and correspondingly decreased loadings of another filler, BaSO 4 . A similar graph is shown for various compositions comparing conductive and non-conductive compounds in FIG. 4 . The plots indicate the somewhat complex relationship between loading and sound transmission. FIGS. 5 and 6 are graphs showing the conductive of various formulations for test plaques and actual housings.
[0072] Table II shows mechanical property testing on Conductive SMCs. The specimens used for testing were cut from 12×12×0.125 inch panels that were molded in the standard method.
TABLE II Mechanical Property X SD X SD SL791-A4 SL791-A5 Tensile Strength (psi) 4807.14 706.65 5097.50 1132.40 Tensile Mod. (psi × 10 6 ) 0.87 0.16 1.02 0.08 % Elongation (percent) 0.80 0.33 0.89 0.31 Tensile Energy (psi) 25.01 14.39 33.33 17.70 Flex Strength (psi) 13456.63 3096.88 13700.25 2947.58 Flex Mod. (psi × 10 6 ) 0.37 0.10 0.94 0.07 Notched Izod (ft-lbs/in) 7.57 2.01 8.69 1.96 Unnotched Izod (ft-lbs/in) 11.98 4.26 14.75 4.54 SL791-A6 SL791-A7 Tensile Strength (psi) 4966.25 801.16 5983.75 2198.74 Tensile Mod. (psi × 10 6 ) 0.95 0.08 1.16 0.20 % Elongation (percent) 0.71 0.14 0.74 0.37 Tensile Energy (psi) 21.30 6.31 32.78 27.55 Flex Strength (psi) 12184.57 1630.66 17144.38 5025.52 Flex Mod. (psi × 10 6 ) 0.87 0.05 0.94 0.12 Notched Izod (ft-lbs/in) 9.15 3.02 12.31 2.87 Unnotched Izod (ft-lbs/in) 12.33 2.12 14.18 4.79
[0073] Table III shows results from flammability testing using samples molded in the standard method and tested according to UL's Test for Flammability of Plastice Materials for Parts in Devices and Applicances. The specimens were conditioned to the first conditioning period (48 hrs@23° C.) only to help meet the date needed.
[0074] Past data has shown no difference in results between the two conditioning periods. If the table recites “NR” testing was Not Required because: 1) testing of the same compound passed at a tower thickness, 2) testing of the same compound failed at a higher thickness. In the parenthesis following a “NR” is the assumed testing result. A hypen shows results from a needed recheck because of a failure. The minimum passing result for each compound is listed in bold.
TABLE III Compound Series Batch Test Type Thickness Result SL791-A4 EXP-15 1 (pilot) V-0 0.060 Fail - Fail 0.080 Pass 0.100 NR (Pass) 5V 0.060 Pass 0.080 NR (Pass) 0.100 NR (Pass) SL791-A5 EXP-15 1 (pilot) V-0 0.060 Fail - Fail 0.080 Pass 0.100 NR (Pass) 5V 0.060 Pass 0.080 NR (Pass) 0.100 NR (Pass) SL791-A6 EXP-15 1 (pilot) V-0 0.060 Fail - Fail 0.080 Fail - Fail 0.100 Pass 5V 0.060 Fail - Pass 0.080 NR (Pass) 0.100 NR (Pass) SL791-A7 EXP-18 1 (pilot) V-0 0.060 Fail - Fail 0.080 Fail - Fail 0.100 Pass 5V 0.060 Pass 0.080 NR (Pass) 0.100 NR (Pass)
[0075] Table IV sets forth Mechanical Property testing as set forth in Table II but for SMC with varying amounts of K100 graphite.
TABLE IV Mechanical SL790-Z4 SL790-Z5 SL790-Z6 Property X SD X SD X SD Tensile Strength (psi) 3612.50 1255.61 5662.50 796.86 3705.00 933.61 Tensile Mod. (psi × 10 6 ) 1.03 0.09 1.18 0.19 1.03 0.21 % Elongation (percent) 0.53 0.38 0.69 0.11 0.42 0.15 Tensile Energy (psi) 9.85 7.25 28.55 10.34 10.21 6.79 Flex Strength (psi) 9557.63 3339.44 11461.88 2629.28 9752.25 3754.08 Flex Mod. (psi × 10 6 ) 0.76 0.09 0.79 0.12 0.71 0.10 Notched Izod (ft-lbs/in) 5.67 1.21 6.03 1.63 6.06 1.48 Unnotched Izod (ft-lbs/in) 9.08 4.16 9.33 3.83 9.53 2.50
[0076] Table V sets forth the results of flammability testing for the compounds of Table IV and according to the description for Table III.
TABLE V Compound Series Batch Test Type Thickness Result SL790-Z4 EXP-15 1 V-0 0.060 ALL PASS 0.080 0.100 5V 0.060 ALL PASS 0.080 0.100 SL790-Z5 EXP-15 1 V-0 0.060 ALL PASS 0.080 0.100 5V 0.060 ALL PASS 0.080 0.100 SL790-Z6 EXP-15 1 V-0 0.060 ALL PASS 0.080 0.100 5V 0.060 ALL PASS 0.080 0.100
[0077] Additional flammability testing results are set forth in Tables VI, VII, and VIII.
TABLE VI Compound Series Lot No. Test Type Thickness Result SL790-Y9 Exp-15 7-14-03-1 V-0 0.060 NR (Fail) (LAB) 0.080 NR (Fail) 0.100 Fail - Fail 5V 0.060 NR (Fail) 0.080 NR (Fail) 0.100 Fail - Fail SL790-Z1 V-0 0.060 NR (Fail) 0.080 NR (Fail) 0.100 Fail - Fail 5V 0.060 NR (Fail) 0.080 NR (Fail) 0.100 Fail - Fail SL790-Z2 V-0 0.060 PASS 0.080 NR (Pass) 0.100 NR (Pass) 5V 0.060 PASS 0.080 NR (Pass) 0.100 NR (Pass) SL790-Z3 V-0 0.060 PASS 0.080 NR (Pass) 0.100 NR (Pass) 5V 0.060 PASS 0.080 NR (Pass) 0.100 NR (Pass)
[0078]
TABLE VII
SAMPLE DESCRIPTION
SL-791-A8 SMC
Exp-18
37%4012Graphite/DBDPO/SB
SL-791-A9 SMC
Exp-20
35%4012Graphite/DBDPO/SB
RESULTS
Compound
Thickness
Test Type
Result
SL-791-A8
0.060
V-0
Pass
5 V
Pass
SL-791-A9
0.060
V-0
Fail/recheck Fail
5 V
Pass
0.080
V-0
Pass
[0079]
TABLE VIII
SAMPLE DESCRIPTION
SL-791-B5 SMC
Exp-18
30%4012Graphite/DBDPO/SB
SL-791-B6 SMC
Exp-20
30%4012Graphite/DBDPO/SB
SL-791-B7 SMC
Exp-15
36%4012/DBDPO/SB
RESULTS
Compound
Thickness
Test Type
Result
SL-791-B5
0.060
V-0
Pass
5 V
Pass
SL-791-B6
0.060
V-0
Pass
5 V
Pass
SL-791-B7
0.060
V-0
Fail/recheck Fail
5 V
Pass
0.080
V-0
Pass
[0080] Testing was performed according to ASTM standards for rigid plastics. Additional tests were run to study the effect of graphite loading and particle size with a preliminary ohm target of 2 ohms, in particular for use as a combination heater/blower housing. The test method to determine through surface conductivity was the same as used to determine the values presented for the plaques in Table I and uses a ohm meter forming a circuit with to ¼″ to ½″ braided copper strap bonded to opposing parallel ground sides at the top, and in line with the edge of a 6″ by 6″ by 0.125″ plaque with the copper strap being bonded to each ground side by silver filled epoxy adhesive. This method is meant to be the method for determining the through surface conductivity for the claims. The results are set forth below in
TABLE IX Graphite K-1100%/ 4012/ Glass Formulation % 250 mic 75μ 94 5V .060″ Ohms % SL790-Y9 40 20 20 fail 1.3 15 SL790-X4 43 43 0 pass 31 15 SL-790-Z2 40 20 20 pass 2.2 15 SL-790-Z3 40 15 25 pass 2.2 15 SL-790-Z6 40 35 5 pass 1.5 15
[0081] While in accordance with the Patent Statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims. | The invention provides molding compounds that are particularly suitable to be molded into an article such as a heating element that will conduct heat and not burn when an electric current is passed through the article. These compounds are generally liquid thermosetting molding resins which comprise a thermoset resin matrix such as a terephthalate polyester which can include blends of polyester and/or vinyl ester with a significant loading of conductive inorganic filler, typically graphite. The compositions also include flame and sound retardant additives, and glass fibers. They are further formulated to meet the desired molding characteristics; to withstand the operating temperatures to which they will be exposed; and to have a predetermined strength and a desirable user interface including appearance, and odor. Typically, the compounds will have a glass transition temperature from about 160° C. (320° F.) to about 195° C. (383° F.). | 2 |
The National stage application filed under 371 of PCT/GB96/01056 filed May 2, 1996.
The present invention relates to food (e.g. protein) products, and in particular to textured plant and/or animal protein products which have a mouthfeel similar to that of meat.
BACKGROUND OF THE INVENTION
The demand for alternative non-meat protein sources in the 1950s led to the development of a number of processes for texturing plant proteins or mixtures of plant and animal proteins to form meat-like materials.
These processes are very diverse, but in many cases three common steps are involved, vizg (1) an initial hydration and mixing step to form a slurry or dough, followed by (2) a shearing (and in some cases heating) step to denature proteins and produce aligned protein fibres (a reducing agent is often present at this stage to promote denaturation by rupture of disulphide bonds), and finally (3) a setting step to fix the fibrous structure, setting often being achieved by rapid temperature and/or pressure change, rapid dehydration or chemical fixation. The restructured material is usually extruded through a die orifice to shape the product prior to setting. One of the most common methods of producing textured proteins is by extrusion cooking (see Gutcho, M. (1973), "Textured foods and allied products", Food Technology Review No. 1, Noyes Data Corporations Park Ridge, N.J., USA, and Harperg J. M. (1981), Chapter 13 "Textured Plant Proteins", in Extrusion of Foods Vol. II, CRC Press Inc., Boca Raton, Fla., the contents of which are incorporated herein by reference).
In this process a protein-rich flour (typically 50-80% protein) is fed into a closed barrel containing one or two screw shafts. The screws convey the material forwards where it is mixed with water and kneaded to form a dough. The dough is then conveyed forward into a zone containing screw elements designed to impart shear, this area also being hot (100-170 degrees centigrade) and under pressure (100-1000 psi). These extreme conditions cause the material to melt and adopt a fibrous character. The fibres become aligned in the direction of shear applied by the screw elements.
The melt is then forced through a single, or a number, of die orifices. As the material extrudes through the die, super-heated water present in the melt flashes off as steam, causing a simultaneous expansion ("puffing") of the material. At this point the material sets, and the process therefore produces a continuous stream of textured product. This process is shown schematically in FIG. 7.
Although fairly dry at this stages the product is usually dried further to increase shelf-life. Before use the product is fully rehydrated (the water absorption of such products is usually in the region of three times their own weight).
Natural fibrous protein sources, such as meat and mycoprotein (sold under the Trade Mark Quorn), have textures which elicit distinctive sensations during chewing and breakdown in the mouth. This mouthfeel is an extremely important acceptability/quality parameter of meat and meat-substitutes, and there is a window of texture associated by consumers with various protein-based products. For example, the rate at which the product breaks down on chewing, the number of chews required before the material can be swallowed, the textures exposed to the teeth and tongue during chewing are all important in determining the acceptability of the product, especially in the case where the product is a meat substitute.
Extrusion of conventional textured protein products, such as those made with soya or wheat proteins tend to result in very fibrous material with a meat-like appearance. However, when hydrated, the system of fibres form a resilient and continuous matrix. The result is a very elastic and tough product which exhibits a poor mouthfeel. Many products have rubbery, tough, slimy and spongy mouthfeels.
One solution to this problem is to use the textured protein products as meat substitutes or analogues in comminuted form. However, this limits their application to products where minced meat would conventionally be used, for example in burgers, sausages and similar products.
Another solution has been to dilute the protein with starchy materials, such as wheat flour or corn starch. However, although this approach has been found to soften the products it does not impart a meat-like mouthfeel--the product is often still too chewy and sliminess may be increased.
It is an object of the present invention to provide food products (for example, textured food products) having an improved mouthfeel.
SUMMARY OF THE INVENTION
According to the present invention there is provided a food product comprising a matrix of fibres having inclusion bodies dispersed therein, the inclusion bodies being intercalated within or between the fibres to weaken or disrupt them and so tenderize the product.
Preferably, the product is an extrudate, the fibre matrix being produced by extrusion.
The fibres may comprise proteinaceous fibres, which may have a protein content greater than 50% (e.g. greater than 80%). They are typically (but not necessarily) those producible by shear-alignment of fibrils (e.g. protein fibrils) during extrusion of slurries or doughs (e.g. through a die orifice of a (twin) screw extruder). They may comprise long bundles of extended peptide chains, linked for example by disulphide bonds.
The product of the invention is preferably a textured protein product.
The textured protein product may be based on any protein or mixture of proteins, including animal proteins (for example low grade meat and/or offals). Preferably, the protein is plant protein (for example plant (e.g. seed) storage proteins), vegetable, leguminous (e.g. soya, pea, ground nut or lupin), cereal (e.g. wheat or maize) or tuberous (e.g. potato), animal, fish or fungal protein, or derivatives/combinations thereof.
The inclusion bodies may be intercalated between and/or within the fibres or fibrils (or bundles thereof). Their precise distribution is not critical to the invention, so long as they serve to weaken or disrupt the proteinaceous fibre matrix (and so tenderize the product).
The inclusion bodies may for example effectively interrupt (or break) the proteinaceous fibres (and/or their inter-/intraconnections) at one or more points along their length, or locally weaken them so that they are prone to breakage at these points.
The action of the inclusion bodies on the fibres may be mediated by purely physical effects (e.g. physical dissociation or perturbation of fibre structure and/or increase in the gross density of the product), by chemical effects (local changes in the chemical constitution of the fibres in the microenvironment surrounding the inclusion body) or by a combination of both.
Without wishing to be bound by any theory, it is thought that the mechanism of action of inclusion bodies comprised of oils and/or fats involves the formation of lipid interfaces within the hydrated protein matrix, which interfaces act as hydrophobic barriers that prevent the formation of a continuous protein network.
The inclusion bodies are produced by adding one or more texture modifying additives to the protein(s) to be textured. The texture modifying additive used during manufacture may be the inclusion bodies in the form in which they are present in the final product (being e.g. in the form of a particulate solid). Alternatively, the additive may be a composition (e.g. a salt solution) which gives rise to inclusion bodies during a subsequent processing step (e.g. during the conditions imposed by extrusion through a die orifice of a twin screw extruder).
Sufficient texture modifying additive is used to give rise to inclusion bodies in the final product at a concentration sufficient to tenderize (and/or soften) the products and preferably at a concentration sufficient to produce a meat-like mouthfeel. In preferred embodiments, the textured protein products of the invention have a clean bite without (or with reduced) rubberiness, sponginess or sliminess.
The optimum concentration of texture modifying additive is readily determinable by titrating the amount of texture-modifying additive against mouthfeel or strength of the end products and depends on the nature of the protein(s) to be textured and the desired mouthfeel In general, for a meat-like mouthfeel lower concentrations are required for pea-based protein products than for gluten-based products
The inclusion bodies may comprise solids liquid or gaseous bodies, or a combination thereof. Preferably, the inclusion bodies comprise mechanically robust particles. The inclusion bodies may comprise oil or fat particles, and particularly preferred is vegetable oil or fat, especially that used in the form of full fat soya flour (e.g. that sold as Trusoy™).
The inclusion bodies may also comprise particles of an inorganic salt. Calcium or magnesium salts are preferred.
The inclusion bodies may comprise an insoluble material, for example an insoluble organic or inorganic salt. Additionally (or alternatively), the inclusion bodies may comprise a soluble or insoluble polymer, for example cellulose particles or fibres.
In a preferred embodiments the inclusion bodies comprise particles of calcium sulphate dihydrate (gypsum). Calcium sulphate dihydrate is an ingredient with unrestricted usage, and this embodiment is particularly advantageous for use with human foodstuffs.
In another preferred embodiments the inclusion bodies comprise particles of dicalcium phosphate. This substance is commonly added at low concentrations during protein processing for various reasons (e.g. nutritional), but is not used to produce tenderizing inclusion bodies.
The inclusion bodies may advantageously comprise mixtures of: (a) gypsum and cellulose, (b) gypsum, cellulose and fat or oil, (c) gypsum and fat or oil, (d) dicalcium phosphate and cellulose, (e) dicalcium phosphate and fat or oil, (f) dicalcium phosphate, cellulose and fat or oil, (g) gypsum and dicalcium phosphate, (h) gypsum, dicalcium phosphate and cellulose and/or fat or oil.
The fat or oil may be pure or in the form of full fat soya flour, and/or incorporated in fat powders or fat-filled powders.
The diameter of the inclusion bodies is preferably similar to that of the proteinaceous fibres. In many embodiments, the inclusion bodies are between 1 and 100 um in diameters for example between 10 and 100 um.
In another aspect the invention relates to a method for producing a food product comprising the steps of: (a) forming a matrix of fibres (e.g. proteinaceous fibres); and (b) introducing discontinuities into the matrix by intercalating discrete inclusion bodies within or between the fibres to weaken or disrupt them.
The inclusion bodies are preferably derived from a texture modifying agent present during the matrix forming step. The matrix may be formed from a proteinaceous slurry, powder or dough, and is conveniently formed by extrusion.
In embodiments in which extrusion is used to create a fibre matrix, the extrusion may be high moisture extrusion, for example at a moisture content of greater than 40%.
Particularly preferred is high moisture extrusion at a moisture content of 40-80% (e.g. 50-70%).
The extrudate may be cooled by means of a cooled die. The cooled die may advantageously comprise a long cooled die, for example greater than 0.3 m in length. Particularly preferred are dies of 0.3-5.0 m (e.g. 2.0-4.0 m) in length.
The extrudate is preferably pumped from the extruder, for example into a die (such as the cooled dies as described above). In these embodiments, the pump (which may for example be a gear pump) may be located between the extruder and die (for example as described in EP0398315).
The invention also relates to a foodstuff (e.g. foodstuff) comprising the product of any one of the preceding embodiments. The foodstuff may advantageously be a meat substitute or meat analogue, and may be in the form of discrete chunks.
The invention also contemplates a method for producing a textured protein product comprising the steps of: (a) forming a matrix of proteinaceous fibres in the presence of a texture modifying agent, and (b) processing the matrix under conditions whereby the texture modifying agent forms discrete inclusion bodies intercalated within or between the fibres to weaken or disrupt them.
The matrix is preferably formed from a proteinaceous slurry or dough, and in step (b) the processing step may comprise extruding the matrix through a die orifice of an extruder, e.g. in a process according to that shown in FIG. 7.
The invention will now be described in greater detail by way of example. The examples are for illustrative purposes only and are not intended to be limiting in any way.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a light micrograph (×425) showing a longitudinal section of extruded wheat gluten with 0.7% cysteine. Aqueous Light Green was used to stain plant protein. This was followed by counterstaining with Lugols iodine solution for plant carbohydrate. This figure shows the dense, continuous protein structure produced by extrusion of wheat gluten with 0.7% cysteine (used as a process aid). The dark particles present have stained black with iodine hence are likely to represent residual non-starch polysaccharide in the gluten.
FIG. 2 is a light micrograph (×425) showing a longitudinal section of extruded gluten containing 0.7% cysteine and 10% calcium sulphate. Staining is as described for FIG. 1. This figure demonstrates the effect of including calcium sulphate in extruded gluten. The structure becomes disrupted (compared to FIG. 1) and unstained particles, thought to be calcium sulphate can be seen interspersed between the proteinaceous fibres.
FIG. 3 is a light micrograph (×425) showing a longitudinal section of extruded gluten containing 0.7% cysteine and 1% vegetable oil. Staining is as described above for FIG. 1. This figure demonstrates the disruptive influence of adding fat to the structure of extruded gluten. This can be compared with FIG. 1 which relates to a sample without added fat.
FIG. 4 is a scanning electron micrograph (SEM) of a longitudinal section of extruded gluten containing 0.7% cysteine. This micrograph shows the relatively smooth fibrous surface.
FIG. 5 is an SEM of a longitudinal section of extruded gluten containing 5% calcium sulphate and 7.5% cellulose (as shown in FIG. 6). This micrograph shows the smooth surface of the protein matrix disrupted by intact particles of cellulose fibre and calcium sulphate.
FIG. 6 is an SEM of a section of extruded gluten containing 0.7% cysteine, 5% calcium sulphate and 7.5% cellulose fibre. The white areas (three examples of which are circled) have been positively identified as calcium sulphate using x-ray elemental mapping. This figure shows the dispersion of particulate material in the protein matrix. Reference to the 100 μm scale bar reveals that particles tend to be in the range 1-75 μm.
FIG. 7 shows in schematic form a typical extrusion process for the production of textured protein products.
FIGS. 8 and 9 show contour diagrams depicting an assessment of eating quality by a panel of experts using a scale from 1.0 (very poor) to 5.0 (excellent).
DESCRIPTION OF PREFERRED EMBODIMENTS
Unless otherwise stated, all percentages are expressed on a dry weight basis.
Example 1
A dry powder mix of gluten, 0.2% sulphur (as a reducing agent) and various amounts of texture modifying additive (dicalcium phosphate and/or Trusoy™) was fed into the feed spout of a Wenger TX52 twin screw extruder (fitted with a single 7 mm circular die orifice) at a rate of 60 kg dry mix per hour. The extruder was also fed with water at a rate of 12 kg per hour. The residence time was about 30 sec, the temperature between 50-160 degrees centigrade and the pressure between atmospheric and 1000 psi (temperature and pressure increasing to peak at the die).
The results are shown in FIG. 8, which shows a contour diagram depicting an assessment of eating quality by a panel of experts using a scale from 1.10 (very poor) to 5.0 (excellent).
The presence of between 8 and 30% of dicalcium phosphate had a beneficial effect on eating quality. The benefit was particularly marked when the dicalcium phosphate was used at fifteen to twenty-five percent along with Trusoy™ at between 0.5 and 4%.
Example 2
A mixture based on wheat gluten dough was prepared as described above, but pure fat or oil replaced the full fat soya flour (Trusoy™) in the texture modifying additive.
Similar results to those shown in FIG. 8 were obtained, indicating that a major functional component of full fat soya flour is the fat (full fat soya flour comprises about 20% fat).
Example 3
A mixture based on wheat gluten dough was prepared as described in Example 1, but calcium sulphate dihydrate (gypsum) was used in place of the dicalcium phosphate at up to 20%.
Similar results to those shown in FIG. 8 were obtained.
Example 4
A mixture based on wheat gluten was prepared as described for Example 3, but cellulose fibre was also added. It was found that cellulose fibre could at least partly replace the calcium salt. The results of the use of various concentrations of calcium sulphate dihydrate and cellulose fibre (along with 2% soya oil) are shown in FIG. 9, which shows a contour diagram depicting an assessment of eating quality by a panel of experts using a scale from 10 (very poor) to 500 (excellent).
Improvement in eating quality were greatest when the levels of cellulose fibre and calcium sulphate were each greater than about 7.5%.
Example 5
A wheat gluten dough was prepared using conventional procedures. Various amounts of texture modifying additive in the form of gypsum and/or vegetable fat (hardened palm oil) were mixed with the dough, and the mixture then extruded using conventional techniques.
The extruded products were rehydrated and subjected to textural analysis using an instron universal texture analyser. The test involves penetrating a set weight of hydrated material with a multi-toothed probe. The energy required to reach the point at which the test material rutures was recorded as a measure of toughness.
The results are shown in Table 1. The show that significantly less energy is required to penetrate material containing gypsum alone, fat alone, or both fat and gypsum compared with a product with no texture modifying additives.
Shown in Table 1, sample 2 containing 5% gypsum requires 22% less energy to break compared to sample 1 (no texture modifying additive). The addition of 1% vegetable table fat (sample 5) reduces the energy to break-point by 34% compared to the no additive control (sample 1). Gypsum and fat have an additive effect when the gypsum is present at 10% or more (samples 7 and 8).
TABLE 1______________________________________The Effect of the Addition of Gypsum and/or Vegetable Fat on theMechanical Strength of Extruded Textured Gluten Energy to Veg Fat Gypsum Break Point Percent Change inSample (%) (%) (mJ) S.D. n = 9 E. to B.P______________________________________1 0 0 8381 750 --2 0 5 6537 759 -223 0 10 5901 561 -304 0 15 5446 442 -355 1 0 5560 311 -346 1 5 5425 167 -357 1 10 4690 375 -448 1 15 4448 348 -47______________________________________
Example 6
A textured gluten chunk product having the composition shown in Table 2 (hereinafter referred to as the Standard formulation) was prepared as described below.
TABLE 2______________________________________ Ingredients %______________________________________ Wheat fibre 5.0 Vitacel fh wf600 Satro 1.5 Hydrogenated Vegetable fat FP75 Gypsum 5.0 Vital Wheat 70.3 Gluten Cysteine 0.7 Hydrochloride Wheat Flour 15.0 Glycerol 1.0 Monostearate Flavour 3.0______________________________________
The ingredients were made up and mixed for 7 minutes using a Gardiner Ribbon Mixer. The insoluble salts, fat and fibres were added at the mixing stage. The mixes were then fed into the K-tron volumetric Wenger TX52 extruder feeder which delivered the mix at a constant throughput (98 kg/hr), to the extruder barrel via the preconditioner. The barrel contained twin screws with a standard configuration. The screws conveyed the material forward where it mixed with water (pumped in at 17%). The material formed a dough which then passed through screw configurations that produced high shear. The pressure and temperature in this region was high (100°-170° C.) which caused the material to melt. The melt was then forced through a single loam square die. The expanded product was then dried at 80° C. for one hour in the APV drier in order to extend the shelf-life. The material was then ready for analysis.
The Instron Universal Texture Analyser was used to measure the tenderness of the product. The test used involves penetrating a set weight of hydrated material with a multi-toothed probe (the Kramer Cell) and recording the energy required to rupture the material. The Kramer cell was fitted to the crosshead of the Instron. The cell consisted of multi-toothed probes which cut the gluten chunks until they fell through the grid of the bottom piece. The Bioyield (N) is the maximum force attained during crushing of the material, and was found to be a good indicator of the textural differences between the varying test samples.
The samples for instron testing were prepared as follows:
(1) Place sample into foil container;
(2) Pour over 200 g of cold tap water;
(3) Cover sample with lid and seal;
(4) Place in a preheated oven at 180° C. for 20 minutes;
(5) Remove from oven and allow samples to equilibriate to room temperature (20°-25° C.);
(6) Note temperature of the chunks prior to testing.
The Bioyield values for products having the composition shown in Table 2 are shown in Tables 4, 6 and 8 (rows designated "Standard").
Example 7
A range of different compositions were prepared as described in Example 6, except that the Satro Fat FP75 was replaced with one of a number of different fats/oils listed in Table 3.
TABLE 3______________________________________Ingredient Source______________________________________Satro Fat FP75 SatroRapeseed Oil Bcoco Ltd. LiverpoolCod Liver Oil Seven Seas Ltd. HullChicken Fat Lucas Ingredients. KingswoodCoconut Oil Anglia Oils Ltd. HumbersideGroundnut Oil Anglia Oils Ltd. HumbersideBeef Suet Spillers Technical Advancement Centre. CambridgeHigh Oleic Sunflower Oil Lucas Ingredients. Kingswood______________________________________
The fats/oils were first melted down in a water bath set at 80 degrees centigrade and then added to 1.5% wt. with a peristaltic pump during extrusion. The results are shown in Table 4.
TABLE 4______________________________________ Bioyield (N)Sample Mean sd______________________________________Control 637.9 43.2Standard 512.5 15.8Rapeseed 492.3 24.4Fish 467.3 37Chicken 492.6 29.1Coconut 499.8 20.7Groundnut 533.1 41.6Beef 506.3 33.3Sunflower 512 39______________________________________
The results indicate that all of the fats/oils tested reduce the Bioyield of the extruded product. As bioyield measures the maximum attained during the crushing of the material, the lower the force, the less effort is required to chew the samples and therefore the more tender the product.
The control (containing no fats/oils), had the highest bioyield values, while the lowest bioyield value was evident in the sample containing fish oil (467.3N),
Generally there was not a great deal of variation in bioyield values for all the fat and oil samples. The groundnut oil seemed to have the least beneficial effect on the texture. No obvious trend was found between vegetable fats/oils and animal fats/oils.
The fat and oil samples were found to be significantly different to the control which contained no fats or oils. Fish oil showed the largest significant differences to the control. None of the fats or oils were significantly different to the standard (Satro fat FP75).
Example 8
A range of different compositions were prepared as described in Example 6, except that the Vitacel fibre WF600 was replaced with one of a number of different fibres as listed in Table 5.
TABLE 5______________________________________Ingredient Source______________________________________Vitacel fibre WF600 Allehem International. BerkshireWheat fibre Isolate ID 95 ID Food Concepts. FranceOat fibre ID 82 ID Food Concepts. FranceBarley fibre 1 ID Food Concepts. FrancePea fibre EXAFINE Cosnera. NetherlandsPotex Potato fibre PP Avebe______________________________________
The fibres were all added to 5.0% wt (the potato and pea fibre were milled down using a cyclone mill to approximately <200 microns). The results are shown in Table 6.
TABLE 6______________________________________ Bioyield (N)Sample Mean sd______________________________________Control 572.3 42.2Standard 512.5 15.8Wheat 540.1 25.4Oat 540.6 41.1Barley 498.8 26Pea 495.9 40.3Potato 447.6 35.7______________________________________
The control (with no added fibres) showed the highest bioyield value. There was no significant variation in bioyield values between the various fibres. Potato fibre produced a relatively low bioyield value which suggests that it has the most tenderising effect on the product. The standard formulation containing Vitacel showed no significant beneficial effect on the texture as compared to the other fibres added.
All the fibres showed a significant difference when compared to the control, except for the sample containing Oat fibre which showed no significant difference at a 5% level in this substituted standard formulation. All fibre types (except for Oat) showed no significant difference when compared to the standard (Vitacel WF600).
Example 9
A range of different compositions were prepared as described in Example 6, except that the gypsum was replaced with one of a number of different insoluble salts as listed in Table 7.
TABLE 7______________________________________Ingredients Source______________________________________Gypsum Annetstar. GrimsbyMagnesium Sulphate Sigma Chemical. UKM7506Dicalcium Phosphate Spillers Petfoods. CambridgeCalcium Carbonate Spillers Petfoods. CambridgeIron Oxide______________________________________
The salts were all added to 5.0% wt. The results are shown in Table 8.
TABLE 8______________________________________ Bioyield (N)Sample Mean sd______________________________________Control 700.6 23.9Standard 512.5 15.8MgSO.sub.4 650.5 29.3DCP 663.6 67CaCO.sub.3 546.8 39.5Iron Oxide 573.8 34.4______________________________________
Gypsum (present in the standard formulation), produced a remarkably low bioyield value compared to the other insoluble salts added. The insoluble salts showed varying degrees of significance when compared to the standard and the control. The standard (gypsum), magnesium sulphate, iron oxide and calcium carbonate showed a significant difference when compared to the control. Calcium carbonate showed no significant difference when compared to gypsum in the standard formulation. Thus gypsum, magnesium sulphate, iron oxide and calcium carbonate significantly improved the texture of the gluten chunk. Calcium carbonate can replace Gypsum in the standard formulation.
The invention is of general application to all fibrous food products, and is not limited to textured protein products comprising proteinaceous fibres. It may be applied, for example, to fibrous carbohydrate products. | A food product comprising a matrix of fibers such as proteinaceous fibers, the matrix having inclusion bodies dispersed therein. The inclusion bodies may be solid, liquid or gases which can be intercalated within or between the fibers so as to weaken and disrupt the integrity of the fibers and tenderize the food products. | 0 |
BACKGROUND OF THE INVENTION
[0001] Piracy has plagued the creative industries since their beginning. The software, book, music and film industries loose billions of dollars each year through illegal copying and distribution of their works. Copyright law is aimed to protect these industries, but with the advent of electronic distribution, the Internet and home CD-RW and DVD-RAM machines, copying has become more insidious and all pervasive than ever before. In the past, piracy was a capital-intensive process, requiring weeks of preparation in a dedicated piracy studio, today piracy is built into every home.
[0002] With every home becoming a potential centre for piracy, the job of enforcing license and copyright law has become impractical. This problem has arguably contributed to the rapid growth of the GNU and Free Software movements with both users and developers accepting the motto: “. . . if you can't stop it, why even try!”.
[0003] The present invention seeks to reduce the impact of media piracy on the creative industries and in particular the software industry. It does this by introducing a new method of electronic media distribution using a network (such as the Internet) where the media is never held in a copyable format on a user's machine but can still be used to its full potential.
BRIEF SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide a method for the secure distribution of electronic media through a network that reduces the risk of piracy. The system as presented works with all electronic media formats including music and film but is particularly suited to instantiable, file-based, electronic media such as software where parts of the media must remain in client memory and may be accessed at random.
[0005] It is a second object of the present invention to provide a simple method for the electronic distribution of software and other electronic media through a network The method, according to the invention, reduces cost and time to market and allows new types of pay-peruse licensing agreements to be enforced.
[0006] These and other objects, advantages and features of the present invention are provided by a new method for the delivery and use of the electronic media through a network. The method comprising at least 3 logical components:
[0007] 1. A License Media Service component (LMS). The LMS component holds the media in a distributable form and validates requests from clients for the media. Once a client's request has been validated against the distributor's license criteria, the LMS sends the requested media items to the client through the network.
[0008] 2. A Client Log-in Component (CLC). This component is responsible for connecting to the LMS through the network, supplying a request for media and validation parameters and receiving the electronic media back through the network.
[0009] 3. A Client Instantiation Component (CIC). The CIC is responsible for instantiating the returned electronic media in a form ready for users to interact with. An example of such instantiation is where the distributed media is Java software class files and these are instantiated as runnable objects by the instantiation component directly in memory. This direct instantiation into volatile memory avoids storing the media on disk or other non-volatile storage where it could be copied. Media instantiation is different in character to merely streaming the media to a client application, using it once and then discarding it as the instantiated object may remain in memory and be randomly accessible as with a software component. Instantiation may require runtime lining and address mapping the distributed media with elements of the operating system or other applications depending on the media type.
[0010] In a method according to the invention, a generic “stub” is installed on a client machine containing both the CLC and CIC components. The stub allows the instantiation and use of different media services delivered by the networked LMS depending on the user request and distributed on an as-needed basis. This reduces the amount of non-volatile storage the client needs. Additionally, as each service is distributed “as-needed”, there is little or no risk of miss-configuration of the media service as it is distributed fresh each time to the client easing the burden of administration. The client stub may also provide generic functionality such as graphics and sound drivers that cross media boundaries as is the case with the preferred Java embodiment.
[0011] In a second method according to the invention, the LMS validates the user based on any combination of username, password, source address, software and hardware identification and other information as supplied through the CLC or request. The LMS then delivers the appropriate licensed media for the user.
[0012] In a further method of the invention, the CLC and CIC components of the client stub are optionally checked by the LMS to see if they have been tampered with before media is sent to the client. If this check were not performed, inventive pirates would be able to change (reengineer) the CLC or CIC components to have them save the media to disk in a copiable format instead of directly instantiating it in memory, this would circumvent the protection afforded by the system. In the preferred embodiment, this checking is performed by the LMS optionally sending a checking executable to the client when the CLC tries to log-in. This executable must be run by the client and generates and returns a hash of the CLC and CIC component files for validation by the LMS.
[0013] In the preferred embodiment of the invention the LMS transfers the media to the CLC over a secure encrypted connection and the CLC transfers the instantiable media to the CIC using shared memory or other highly volatile storage, rather than storing the media temporarily on disk. The CIC can then instantiate the media directly in its own process or pass it to a running process perhaps again through shared memory or through a application secured virtual file system.
[0014] In another embodiment of the system according to the invention the CLC stores the media temporarily on the client machine or a network file store for a CIC to instantiate. The advantage of this embodiment is that only a single network transfer is required for the media from the LMS and, provided the media is not updated, the same stored encrypted files can be used by many CIC instances potentially across many clients on a LAN. In this embodiment, the storage is preferably in an encrypted format and the file decryption key is needed by each CIC component.
[0015] In yet another embodiment of the system according to the invention the media is passed directly to the CIC from the LMS instead of being transferred through the CLC. This has the advantage of removing the need for shared memory and may be implemented through an FTP like control and data channel (CLC and CIC channel), a combined functionality CLC+CIC component, a dependant dual connect or a well known CIC port or similar.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Embodiments of the invention will now be disclosed, for example purposes only and without limitation, with reference to the accompanying drawings, in which:
[0017] [0017]FIG. 1 shows the network architecture of the preferred embodiment.
[0018] [0018]FIG. 2 shows the deployment architecture of the LMS, CLC and CIC components in the preferred embodiment.
[0019] [0019]FIG. 3 shows the process for distributing a simple Java software application from the LMS to the client and starting it assuming no errors.
[0020] [0020]FIG. 4 shows a simple license database structure.
DETAILED DESCRIPTION
[0021] A preferred embodiment of the invention will now be disclosed, without the intention of a limitation, in a computer system for the purpose of delivering Java application software to users. Java is a powerful programming language but many professional commercial programmers have shied away from using it because it is too easy to de-compile and recover the Java source code from distributable Java byte-code classes and programs. This ease of de-compilation means that the secrets of commercial software products can be obtained and that licensing measures imbedded into software easily circumvented if that software is written in Java. By using the invention as disclosed in this embodiment the Java software class files are never stored in a copyable format on the user's machine and thus can not be read as files by a Java de-compilation program but can still be used without limitation.
[0022] [0022]FIGS. 1 and 2 shows the architecture of the preferred embodiment. In this preferred embodiment, the CLC and CIC are implemented in software and reside on the same client machine. The LMS is a server component located on a networked machine on the Internet that the client machine can access.
[0023] [0023]FIG. 3 shows the process of distributing a simple (single class) Java application from the IMS to the client and starting it. The main stages of this process are:
[0024] 1. The LIMS service is started and waits for client requests from the Internet.
[0025] 2. The user starts-up the CLC on the client machine.
[0026] 3. The user enters validation credentials into the CLC. In the preferred embodiment, these credentials are simply a username and password.
[0027] 4. The CLC opens a secure network connection to the LMS. In the preferred embodiment this is an SSL client connection over TCP/IP.
[0028] 5. The CLC sends the username and password over the secure connection to the LMS.
[0029] 6. The LMS validates the username and password against its license database and, in the preferred embodiment, obtains a control file for the Java application the user has licensed. The control file consists of a set of instructions that that the CLC must interpret in sequence to complete the distribution process.
[0030] 7. The LMS returns the control file to the CLC through the still-open, now validated, secure SSL connection.
[0031] 8. The CLC executes each command in the command file in sequence. Typical commands are to request a specific component of the Java application from the LMS through the validated secure connection and pass the returned class file to the CIC component for storage in an instantable class hash. The command file typically ends with the name of the class that should be started first in the CIC and an exit command
[0032] 9. The secure, validated, CLC to LMS connection is terminated by the CLC after the command file is completed or when an EXIT command is interpreted. The CLC process then ends leaving the CIC as a separate operating system process running the Java software.
[0033] In accordance with the present invention, the CLC uses an encrypted secure connection to communicate with the LMS to prevent network “sniffers” from obtaining either the user credentials or the returned instantiable Java classes. In the preferred embodiment, encryption protection is provided through the use of Secure Socket Layer (SSL) communications.
[0034] In a first embodiment of the invention, a simple license database is used by the LMS to validate users. This database has two purposes. Firstly, it holds the relation between usernames and passwords so that users can be validated. Secondly, it holds the relation between validated usernames and the software files they are allowed to request from the LMS. This allows the same LMS to serve different Java applications to different users depending on their Licensed Software Group. The database can be relational in format and may contain at least a user and a file table an example for which is provided in FIG. 4.
[0035] In step 6 above, the username is validated against the password in the user table, the correct Licensed Software Group found and associated with the network connection by the LMS and finally, the command file name/address is located from the file table for the users Licensed Software Group. There should be only one command file per Licensed Software Group (this could change if each users' settings are stored on the LMS) and this strictly means that there should be a separate License Software Group/Command File join table between the user and file tables, but for simplicity, a flag is used in the file table here to mark the file that contains the CLC interpretable commands for a Licensed Software Group.
[0036] Once the LMS has validated the user, identified their licensed software group and located the command file for that group, the LMS reads the correct command file and sends it through the secure connection back to the client CLC component. The command file is preferably located on the LMS machine on the Internet as are the other files in the file table, but this is implementation dependant.
[0037] In a first embodiment, the command file has only a very limited set of commands and transfers files into a local temporary buffer “unnamed” before saving the file media to its ultimate destination as a second, separate command. Example commands in this first embodiment are:
[0038] 1. GET <file>. The CLC sends a request for the file named <file> to the LMS server through the open, validated, secure network connection. The LMS checks to confirm that the validated user is allowed to access this file by looking-up the file and user's Licensed Software Group in the file table of the license database. If the user is allowed to access the file, the LMS sends it back preceded by an OK header and the CLC stores the file by overwriting its file temporary buffer. Otherwise, the LMS sends an error header back to the CLC and may terminate the secure connection with the CLC immediately thereafter.
[0039] 2. STOREAS <path and name>. Stores the contents of the CLC's temporary storage buffer to the local operating system file named in the argument. By default, the file is overwritten. If the CLC temporary file buffer is empty (a malformed command) or the operating system file locked, the CLC may terminate with an appropriate warning to the user.
[0040] 3. RUN <command and parameters>[\wait]. Runs a separate operating system shell command. This command can be used to run executables, delete files or update stub components.
[0041] 4. CICAS <class name>Transfers the contents of the CLC's temporary storage buffer to the CIC as a class named <class name>.
[0042] 5. CICRUN <class name>. The CLC tells the CIC to start the class it has previously transferred to it named <class name>. This class is usually a top-level Java class and may invoke methods of other classes previously loaded into the CIC's class buffer by the CLC.
[0043] 6. EXIT the CLC program terminates. All remaining temporary buffer content is deleted and the validated connection to the LMS is closed.
[0044] With only these 6 limited CLC commands it is possible to:
[0045] 1. Update the client stub by transferring a zipped executable and then running it on the client. The executable can unpack compressed update files and overwrite the files of the CLC and CIC stub on the client. An example CLC command file would be: GET update.exe; STOREAS c:\temp\update.exe; RUN c:\temp\update.exe; EXIT
[0046] 2. Ensure that the client stub CLC and CIC components have not been tampered with before transferring any licensed Java software. An example CLC command file would be:
[0047] GET check.exe; STOREAS c:\temp\check.exe; RUN “c:\temp\check.exe unique cookie”
[0048] 3. Securely obtain and run Java software classes. An example CLC command file would be:
[0049] GET java.class; CICAS runnable_class; CICRUN runnable_class; EXIT
[0050] In the preferred embodiment, the client stub CLC and CIC components are validated by transferring a checking executable to the client and starting it with a unique cookie. The executable calculates the hash codes of all of the CLC and CIC component software and dependencies to ensure that they have not been tampered with. In the first embodiment this is performed with the secure hash (sha1) algorithm.
[0051] The executable then returns the hashes to the LMS along with the unique cookie. The LMS requires the unique cookie to be returned to it to confirm that the CLC and CIC hashes are from the same executable it sent to the client and to prevent malicious clients reverse-engineering the hashing software.
[0052] In the preferred embodiment, the hash executable is sent to the client machine on every login, but it is understood that checking client CLC and CIC stubs at random may be more appropriate. Where checking is performed, the check executable is the first thing that must be requested by the client after the command file had been sent to it by the LMS. After that the LMS suspends the transfer of any other files requested by the CLC until it receives and verifies the CLC and CIC hashes generated by the check executable. These hashes will be received on a new SSL connection at the LMS but with the unique cookie, it is possible for the LMS to resume this CLC's connection.
[0053] It only remains now to discuss the CLC to CIC component interaction and the instantiation process in more detail. For a first preferred embodiment, the CLC and CIC functionality is provided in a single as Java application stub installed on the client. This simplifies the instantiation of the delivered Java class files greatly. The combined CLC and CIC Java application is started in a new JVM by the user clicking on an icon or otherwise. The CLC part of the application collects user log-in information, validates through a secure connection with the LMS, gets the command file, retrieves each Java class file into temporary storage and then passes those storage bytes on to the CIC with the name of the corresponding Java class.
[0054] The CIC part of the application can be an implementation of the SecureClassLoader or ClassLoader Java interfaces. The CIC casts and stores the passed temporary storage bytes as a Java class file in a private object hash, indexed on the class name specified in the CICAS command from the CLC. When the CLC finishes loading all the classes through the secure LMS connection, it sends a CICRUN command to the CIC SecureClassLoader implementation class with the name of the route runnable class for the licensed Java application. The CIC then retrieves this class from its private object hash by name, casts it to a Java runnable and calls the run method. Since the Java media's root class is started from a SecureClassLoader implementation, any classes required for the execution of the root application class will be requested through the same CIC by the JVM and the CIC will return objects based on the classes it has been fed from the CLC.
[0055] As an alternative to a 100% pure Java implementation, a second embodiment implements the CLC functionality as a separate native operating system executable. This has the advantage of hiding the internal workings of the CLC log-in and validation component as this would otherwise be distributed to clients in a Java file that could be reverse-engineered. The only drawback with this approach is one of implementation difficulty as the CIC is still in Java and the CLC and CIC must now communicate through Java Native Interface or similar.
[0056] In a modification of the above, the CLC is an executable and transfers class files and commands to a Java based CIC using UDP or TCP/IP sockets on the client machine on a known port. This means that the same CIC can be used for multiple CLC log-in sessions and common classes shared amongst Java applications without the need for reloading them. This obviously saves resources, but has a drawback in that it is now necessary for the CLC to validate that the CIC has not been tampered with before it passes it any instantiable classes. | This invention presents a method or system for the secure distribution of electronic media through a network. The method is unique in that it protects a distributor's license and copyrights even when distributing random-access electronic media such as software and books. To achieve this benefit, the invention uses 3 components: a Licence Media Service (LMS), a Client Log-in Component (CLC) and a secure Client Instantiation Component (CIC). The client uses the CLC to identify itself to the LMS and request the media. The LMS validates the user and sends only allowed media components back to the client. The CLC then passes these components on to the CIC which instantiates them directly in client memory, without first saving them to disk, drastically reducing the risk of piracy as the media is never stored per-sea on the client machine. | 7 |
[0001] The invention relates to a ratio changing method and apparatus.
[0002] Reduction of rotational frequency and, less commonly, generation or increase of rotational frequency are often required when linking a motor to a load. It is also useful to produce a variable output from a variable input. The present invention proposes to change rotational frequency and provide a continuously variable drive by a new variation on the oscillating hypocycloidal principle.
BACKGROUND
[0003] The hypocycloidal principle involves making a gear wheel “walk” round the inner circumference of a ring gear, or vice-versa, thus imparting a rotation to the other member that is counter to the direction of oscillation. Commercially available groups of reducers use a similar principle. The most common is the harmonic wave drive which uses a flexible geared spline which is pressed by an inner wave generator at opposite points against an outer fixed gear ring, thereby transferring rotation to the flexspine at high reduction ratios. The output rotates contrary to the input, which is advantageous because it reduces the reaction force required to be supplied by the mount. The layout is that an inner dual pressure wave input forces a flexible end of a cup shaped transfer ring against a fixed outer ring. Output is taken from the rigid bottom of the cup and is in a contra direction to the input. However, this type of reducer is expensive, the flexspine is subject to fatigue failure and it cannot be made continuously variable.
[0004] It is also known to use a non flexible hypocycloidal principle whereby the input is divided between two or more eccentric cams rotating within a ring having internal gears and causing it to wobble round an inner gear and so impart rotation to it. The layout is that multiple eccentrics rotate in holes in a ring with internal gears causing the ring to oscillate round an inner output gear, producing rotation contra to input direction. This design has low torsional wind up, but is complex and sliding of the eccentric cams make it inefficient.
[0005] A further type of hypocycloidal drive sometimes called a quadrant drive uses a cam on the input to cause a gear to wobble and roll round within a ring gear from which output is taken. The layout comprises an eccentric central input which rotates within a central gear wheel causing it to oscillate against the geared inner side of a fixed ring gear. The reaction produces a contra rotation in the oscillating gear. A further eccentric stage cancels the oscillation to produce simple rotation.
[0006] A further group is the cyclo drive. It employs an eccentric inner input to oscillate a central disc, which is restrained by outer rollers. The output means has roller pins, which extend into holes in the oscillating disc. Output is contra to input. This is essentially the same layout as the quadrant drive except that the eccentric output is cancelled by the roller pins on the output, rather than by a separate stage. This design is inherently expensive because of the large numbers of components and roller bearings.
[0007] The invention is set out in the claims. The invention provides a less complex and expensive layout than known approaches, can be employed in both friction and positive embodiments and can be used in both fixed ratios and continuously variable embodiments. Further advantages are set out in the following description.
[0008] Embodiments of the invention will now be described, by way of example, with reference to the drawings with which:
[0009] FIG. 1 is a schematic end view showing the general principle of an apparatus according to the present invention;
[0010] FIG. 2 a shows a schematic end view of a first fixed ratio embodiment of the invention;
[0011] FIG. 2 b shows a side view of the embodiment of FIG. 2 a;
[0012] FIG. 3 a shows a schematic end view of a second fixed ratio embodiment of the invention;
[0013] FIG. 3 b shows a side view of the embodiment of FIG. 3 a;
[0014] FIG. 4 a shows a schematic end view of a third fixed ratio embodiment of the invention;
[0015] FIG. 4 b shows a side view of the embodiment of FIG. 4 a;
[0016] FIG. 5 a shows a schematic end view of a fourth fixed ratio embodiment of the invention; FIG. 5 b shows a side view of the embodiment of FIG. 5 a;
[0017] FIG. 6 a shows a schematic end view of a first continuously variable ratio of the present invention;
[0018] FIG. 6 b shows a side view of the embodiment of FIG. 6 a;
[0019] FIG. 7 a shows a schematic end view of a second continuously variable ratio embodiment of the present invention;
[0020] FIG. 7 b shows a side view of the embodiment of FIG. 7 a;
[0021] FIG. 8 is a schematic end view of a first embodiment of an induction type electric motor according to the invention;
[0022] FIG. 9 is a schematic end view of a second embodiment of an induction type electric motor according to the invention;
[0023] FIG. 10 a is a schematic end view of a further embodiment of a fixed ratio device according to the present invention; and
[0024] FIG. 10 b is a schematic side view of the embodiment of FIG. 10 a.
DESCRIPTION
[0025] In overview the present invention employs a hypocycloidal means as shown in principle in FIG. 1 by oscillating a intermediate transfer ring ( 1 ) by means of a rotating pressure input embodied in a freely rotating wheel ( 2 ), that orbits around an input staff which is co-axial with an inner output ( 3 ) that is radially fixed but rotatable. The transfer ring is compliantly tethered by suitable means to prevent it rotating but allowing it to oscillate about the inner output ( 3 ). Increased leverage makes the force applied rise steeply when the pressure wheel ( 2 ) rotates and tries to force the contact point ( 5 ) with the intermediate ring ( 1 ) off a notional line ( 6 ) connecting the contact point and centres of the output wheel and the transfer ring causing the ring to oscillate and the output ( 3 ) to rotate. Output direction is contra to input. The rotating pressure may be on the outside of the transfer ring, pressing the transfer ring directly against the inner output wheel, or may act on the inside of the transfer ring, pressing outwards and forcing the opposite side of the transfer ring against the inner output wheel. Also the rotating pressure may consist of two or more pressure points on either side of the contact point between transfer ring and inner output wheel. Transfer of torque between the transfer ring and the output wheel may be by usual friction means or by positive means such as teeth or roller teeth.
[0026] The present invention is capable of being finely balanced because the input and the transfer ring move as one mass with unchanging weight distribution. Optional disconnection of output from input can be effected by moving the rotating pressure wheel or wheels away from the transfer ring, allowing the transfer ring to disengage from the output wheel. This is suitable for friction versions because of the ease of re-engagement between smooth surfaces. A method suited to both friction and geared output, is to release the tether on the transfer ring. In this method the transfer ring is attached by compliant means to a base that is selectively free to rotate ( FIG. 1 ). When the base is allowed to rotate, the transfer ring rotates with the output and no torque is passed to the output. A brake applied to the rotating base stops the base rotating and torque is transferred to the output. The level of friction applied by the brake after lockup can be selected to give torque limiting overload protection.
[0027] The tethered transfer ring acts between the input and output to transfer torque. In a reversed system input is by oscillation of the central gear as in some known hypocycloidals and output taken from the ring gear. In such an embodiment the central gear becomes a transfer ring between the oscillating input and the ring gear and must be compliantly tethered in the manner generally discussed herein in order to pass torque.
[0028] Input to the transfer ring can be to the outer circumference of the transfer ring or to an inner circumference of a transfer ring. The tether can be a compliant ring, tube, membrane. spring, bellows or other suitable compliant tether to prevent the transfer ring from rotating. The tether may act on the ring from a mount from any suitable direction, but radially outwards or inwards or co-axial with the output are most advantageous. Because the transfer ring can be sealed at the input end when input is to the outer circumference of the ring, or an internal partition ( FIG. 4 ) can be supplied to divide the output side from the input side when input is to the internal circumference of the ring, the drive can pass rotary power without a rotating seal. Such ability is advantageous in industries processing volatile chemicals or foodstuffs because it prevents the passage of contaminants.
[0029] Simple lubrication can be effected by enclosing the transfer ring with a plate on one side and a flexible boot on the side from which output is taken ( FIG. 4 ). This boot may form the tether. If the drive is by friction this can seal in a traction fluid. Because the ring wobbles and does not rotate the lubricant or fluid will drip to the bottom of the tether ring, where progressively different portions of the output gear dip into it on each oscillation of the transfer ring. Thus little lubricant is required, reducing losses associated with churning. A magnetic trap for wear particles may be placed at the base of the oscillating ring. The strength of the tethering forces at varying points around the transfer ring may be adjusted to account for any off balance mass of the lubricant.
[0030] In more complex embodiments the transfer ring may be provided with internal channels or surface mounted tubes for the circulation of lubricant or cooling fluid ( FIG. 3 ). Lubricant can be pumped efficiently by providing a open tube and one-way valve that is thrust into a lubricant pool under the transfer ring on the downward oscillations of the transfer ring. If cooling fluid is exchanged with an external heat exchanger the oscillation of the transfer ring will cause liquid in channels within or attached to the ring to be thrown in the direction of oscillation. Thus the drive provides its own pumping mechanism.
[0031] Turning to the specific embodiments in more detail, in a first simple fixed ratio geared embodiment ( FIGS. 2 a and 2 b ), there is provided an input drive element comprising an input shaft ( 21 ) fixedly mounted on which is a leaf spring beam ( 22 ) on the other end of which is mounted a freely rotating roller ( 23 ). An output drive element comprises an output shaft ( 24 ) co-axial with but independently rotatable of the input shaft ( 21 ) and mounted thereon a gear wheel ( 25 ). Between the gear wheel ( 25 ) and the roller ( 23 ) is sandwiched a transfer element comprising a substantially circular transfer ring ( 26 ) with internal gears. The transfer ring ( 26 ) is restrained from rotation by an elastic sheet ( 27 ) connected to a rotatable disc mount ( 28 ) which can be prevented from rotating by the application of a block brake ( 29 ). In operation the input shaft ( 21 ) rotates causing the roller ( 23 ) on the beam ( 22 ) to also rotate around the same axis. This applies a rising compliant pressure to one side of a notional line joining the contact point of the transfer ring and the output gear and their respective centres. This pressure acts on the transfer ring ( 26 ) in the manner of a lever against the fulcrum, which in this case is the contact point between the transfer ring and the output wheel. The further the pressure moves away from the contact point the greater the leverage. The transfer ring is prevented from rotating by the tethering sheet and cannot rotate, so the pressure forces the transfer ring to oscillate around the inner gear, following the roller ( 3 ), causing the inner gear ( 25 ) to rotate contra to the direction in which the pressure wheel is rolling. If the rotational force reaction in the transfer ring rises sufficiently to overcome the friction of the brake ( 29 ), the rotatable disc mount ( 28 ) will slip and rotate, the transfer ring will then rotate rather than wobble and no torque will be transmitted to the output. Slippage can be operator activated to de-clutch the drive, or pre-set as overload protection.
[0032] In a second fixed ratio embodiment ( FIGS. 3 a and 3 b ), which operates in the same manner as the first, the tether to restrain the transfer ring ( 36 ) from rotating against a wheel ( 33 ) is a number of coil springs ( 34 ) which attach the transfer ring to the unit housing allowing driving of the output ( 35 ). The transfer ring is provided with an internal channel ( 312 ) through which cooling fluid is circulated. The cooling fluid is supplied from to and from the reservoir by flexible pipes ( 313 ) running through the coil springs and is pumped by oscillation of the ring as described above.
[0033] In a third fixed ratio embodiment ( FIGS. 4 a and 4 b ), operating in the same manner as the first, the tether is provided by a bellows ( 41 ) connecting the transfer ring ( 46 ) to an outer casing ( 42 ). A partition ( 43 ) is provided in the transfer ring to seal the output ( 44 ) from the input side. Thus in operation no matter of any kind can pass from the input side or the output side and rotary power can be passed without the necessity of a rotating seal. This embodiment is supplied with two input wheels ( 44 ), by way of illustration of the variety of possibilities.
[0034] In a fourth fixed ratio embodiment ( FIGS. 5 a and 5 b ) operating in the same manner as the first an input wheel ( 51 ) is provided that rotates within the transfer ring ( 52 ) opposite the contact point between transfer ring and inner output wheel ( 53 ). The tether is supplied by a rubber ring ( 54 ) between the transfer ring and the casing ( 55 ). This embodiment is advantageously compact.
[0035] The use of pressure waves to drive piezo effect motors is known, but these do not employ a transfer ring to obtain a walking contra rotation effect and rely on direct frictional force to drive the output in the same direction as the pressure wave. In such motors it would be advantageous to use a transfer ring and so increase the torque output through reduction. In a similar manner the present invention may incorporate phased electromagnetic means to oscillate the transfer ring, which may contain permanent magnets.
[0036] Electric motors of known rotary and linear types work by the action of magnetic fields on other magnetic fields or on magnetic material. Both methods, as applied in all types of conventional rotary and linear electric motors, may be used to create an electric motor using a tethered oscillating ring in place of a rotor. Using an oscillating “rotor” or ring provides advantages of build cost and number of parts. Because the ring does not rotate, continuous access can be obtained to supply electrical current to the ring for energising electromagnetic coils without requiring brush slip rings. Also magnetic flux fields can be arranged to act from any direction on magnetic fields or material in the ring or that which is mounted on it, or induced in it. Thus one pole of a coil may act on one side of a disc shaped ring and the other pole on the other side, or one pole may act on the outside of a ring and the other pole on the inside.
[0037] Furthermore, because each molecule of the ring rotates in a circle whose circumference is equal to the contra rotation of the output per oscillation, the maximum velocity of any molecule is many times lower than in a conventional rotor. This lower speed enables the construction of extremely large diameter motors, without problems of force disintegration from high speed and mass that lead to structural failure in rotors of conventional electric motors. This oscillating principle of operation also enables the building of extremely fast switched motors with resulting high power density. Such a fast motor runs much cooler and more efficiently than a conventional rotary motor. Because the ring and stator coils roll on each other and do not have relative surface movement the air gap can be zero at some stages of flux generation, generating high forces, and requiring a smaller number of smaller coils for a particular load than a conventional electric motor.
[0038] Any method of building conventional rotary or linear electric motors can be adapted to building oscillating motors, for example, but not limited to using permanent magnets on the ring with static coils, or static permanent magnets and coils on the ring, or static coils inducing opposing fields in the ring, or coils on the ring inducing opposing fields in static elements.
[0039] This approach can be further understood from the embodiments shown in FIGS. 8 and 9 .
[0040] In a simple ( FIG. 8 ) embodiment of an induction type electric motor according to the principle of a rotating pressure force applied to an oscillating ring from outside the ring, there is provided a substantially rigid ring ( 81 ), compliantly tethered as described previously. The ring is provided with internal gearing ( 82 ) co-operating with an inner, smaller geared output ( 83 ). The ring is also provided with an encircling iron shielding layer ( 84 ) on which are mounted aluminium or copper sections ( 85 ), which may be discrete or shorted together around the ring. Electromagnetic stator coils ( 86 ) are provided round the ring, concentric with the output axis. These coils are switched on and off in sequence round the ring. When a coil is switched on it, its flux induces an opposing magnetic flux field in the neighbouring aluminium or copper section. Repulsive force between the fields pushes the ring inwards towards the output. This causes a contact area between transfer ring and output to roll around the output and drive it. The ring is restrained from rotation by mechanical or magnetic means for example a tether of the type described above and these means may also be used to ensure that the ring and output are in mesh even when the motor is not operating. Clearly such a motor can be operated in stepping mode.
[0041] In a second embodiment ( FIG. 9 ) of an induction motor the transfer ring ( 91 ) is flexible and consists of a flexible steel ring ( 92 ) with aluminium or copper sections, which may be shorted together, attached to the inside of the ring. Inside the ring are provided static electromagnetic coils ( 93 ). Outside the ring is provided an output ring ( 94 ) operating on a fixed axis. The coils are switched on and off to provide one or more rotating magnetic fields, which repulse the flexible ring, creating waves in the flexible ring. The wave tops are at a radially greater distance from the centre of the motor and contact the output ring drive by frictional means to drive it. This motor will drive the external ring at near unity ratio in the direction of the wave travel.
[0042] Clearly the torque and output speed of electric motors of this kind may be varied by varying the relative dimensions of transfer ring and output in the ways described above.
[0043] The ratio of hypocycloidals is determined by the difference in the length of two interacting surfaces, which roll together. This effect is usually described as arising from the difference in number of teeth rather than difference in length as previous hypocycloidals have all been geared. The surfaces do not have to be endless or fixedly circular. A change in length of either interacting surface changes the ratio. The effect of walking a ring once around an inner wheel in a hypocycloidal manner without slipping is to produce a contra rotation in the inner ring equal to the difference in the interacting circumferences. From this it will be appreciated that hypocycloids give increasing reduction as the length of their interacting circumferences converge and vice-versa. For example, with a walking ring of inner circumference 65 mm and a driven wheel of 54 mm the reduction ratio is approximately 4.9:1. However if the driven wheel is expanded to 63.5 mm a ratio of approximately 36:1 is obtained. If the driven wheel is expanded to 64.5 mm a reduction ratio of 108:1 results. Thus, by expanding the radius of the output driven wheel by 18% a reduction ratio of approximately 22 times the original 4.9:1 ratio is achieved. This is a greater range than any other mechanical continuously variable drive. If a ratio range similar to an auto gearbox is required (5:1) and with overall drive-train reduction varying between 20:1 and 100:1 a radius change of less than 5% is required. Either changing the inner circumference of the transfer ring or the circumference of the inner driven wheel, or changing both, changes the ratio. Generally it will be preferred to change ratio by changing the transfer ring, because it wobbles rather than rotates. This enables easy access to the ring for actuation of the change. Locally varying the thickness between inner and outer circumferences of the transfer ring has the effect of a cam within each rotating of the input. This effect can be used to smooth torque and speed fluctuations in the input, such as when the motive power is supplied by an internal combustion engine.
[0044] Various methods of changing circumferences can be used, such as mechanical, hydraulic, pneumatic and electric actuators acting on either the transfer ring, the output wheel, or both.
[0045] In a preferred embodiment ( FIGS. 6 a and 6 b ) overlapping ends ( 61 ) of an open transfer ring ( 62 ) are connected by a variable length screw actuator ( 63 ). The transfer ring is sandwiched in pressure contact between an inner output wheel ( 64 ) and outer ( 65 ) and inner ( 66 ) input wheels, mounted on an arm ( 67 ) on an input shaft ( 68 ) to rotate about the same axis as the inner output wheel. In operation the system rotates, oscillate and outputs reduced rotation as described above, but varying the length of the actuator changes the degree of overlap, thus changing the length of the inner circumference of the transfer ring and thereby changing the ratio. If the ratio is changing while the system is operating, the change should preferably be effected when the overlap is on the opposite side of the transfer ring from the point of contact between the transfer ring and the output wheel. The overlapping ends preferably comprise multiple interlocking fingers ( 69 ) which slide together and are sufficiently compliant to allow a smooth passage of the output wheel at all variable lengths. This layout may be frictional or positive. When positive the actuator must move in defined steps to ensure accurate registration of teeth etc. on the two overlapping ends of the transfer ring.
[0046] In a second preferred embodiment of a continuously variable version of the invention ( FIGS. 7 a and 7 b ) operating in the manner described above, the transfer ring comprises an elastic pneumatic tube ( 71 ), connected by a flexible tube ( 72 ) to a pneumatic controller ( 73 ). Rotating pressure is supplied by two input wheels ( 74 ) connected by a tension spring ( 75 ). The wheels are mounted on arms ( 76 ), which are rotatably mounted on an arm ( 77 ) fixed to the input shaft ( 77 ). In operation the input shaft ( 78 ) rotates the wheels which are pressed against the transfer ring by the spring forcing them together. The transfer ring oscillates in the above described manner and transfers torque at reduced ratio to the output wheel. Increased reduction is achieved by the controller admitting more air to the transfer ring tube. This expands and reduces the inner circumference of the tube and so changes the ratio. The effect is reversed by allowing air out of the transfer tube and increasing the ratio. This embodiment would provide a reducer of low mass.
[0047] In a further embodiment of a fixed ratio device shown in FIGS. 10 a and 10 b there is provided first, a rotating input ( 101 ) on which are mounted more than two, but preferably four rollers ( 102 ), which may be moveable on a mount ( 103 ). The rollers are concentric with the input axis. Secondly there is provided a flexible and tethered transfer ring ( 104 ) which has internal gearing teeth ( 105 ) and encircles and co-operates with a geared output ( 106 ), which has fewer teeth. In operation the input rotates and the rollers roll around the transfer ring on a flexible pathway ( 107 ) that may be reinforced, for example by a flexible steel ring ( 108 ). The four rollers are installed so that the teeth on the transfer ring are pressed into engagement with the geared output between the rollers of opposing pairs of rollers but are unable to contact the inner output gear between the pairs because the length of flexible transfer ring between the pairs of rollers is greater than the corresponding length of toothed output between the pairs of rollers. Thus as the rollers roll round the ring loops ( 108 ) of non-contacting transfer ring travel round with the rollers. Drive is transmitted in contra direction to input in the usual way for hypocycloidals.
[0048] The outward bend at the ends of the loops help reduce engagement friction and noise between the output gear teeth and the teeth on the inside of the transfer ring.
[0049] By changing the output gear to a different size and changing the span of roller pairs the input to output ratio may be changed. The drive torque comes from the reaction of the tether and varies over the two areas of contacting teeth. It is greatest near the trailing roller of each pair and the roller, operating at a fixed circumference from the output axis, prevents tooth separation. Although the embodiment described is geared, it could also operate by frictional means.
[0050] Such a drive is compact and does not require lubrication. It has high torque capacity because of the large numbers of teeth engaged at any time and the fact that, unlike a belt drive, the torque is not transmitted just through a narrow reinforcing band above the teeth. Furthermore the rotating mass and the torque transmitted are equal on opposite sides of the output gear, providing a balanced load on the bearing and long life as well as vibration isolation between motor and load.
[0051] It will be appreciated that there are a large number of different permutations of features described in these preferred embodiments and that different features from different embodiments might be used in particular applications or juxtaposed or combined, without departing from the spirit of the invention. It will also be appreciated that the system described can be reversed to provide generation of increased rotary speed. | A ratio changing method and apparatus includes, in a hypocycle arrangement, an input drive wheel ( 2 ), an output drive wheel ( 3 ) and a transfer ring ( 1 ). The input drive wheel ( 2 ) drives around the exterior of the transfer ring ( 1 ). The transfer ring ( 1 ) is constrained against rotation about its own axis but oscillates about the outward drive wheel ( 3 ), in parting rotation to the output drive wheel ( 3 ) as a result a simple and effective ratio changing apparatus is provided. | 5 |
TECHNICAL FIELD
The present invention relates to an inkjet recording device and the printing control method of the same in which an ink particularized from the nozzle is continuously ejected.
BACKGROUND ART
As one of the prior art references relevant to the present invention, Patent Literature 1 (corresponding to International Application Publication No. WO2008/102458) is exemplified herein, which discloses ‘A condition of the ink droplets is represented by a black filled circle and a triangle in relation to the electrification waveform, in which the black filled circle represents charged ink droplets to be used for the printing and the triangle represents the non-charged ink droplets which are not used for the printing. The non-charged ink droplets have a role containing that it becomes a blank domain of the matrix character to be printed and it adjusts a time period between the longitudinal dot columns. In either case, the electric charge is not applied to the ink droplets such that the formed ink droplets are collected at the gutter 15 without jumping out them from the head. A slow speed printing condition shown in FIG. 14 and FIG. 15 indicates that the speed of traveling the printing object is relatively slow in comparison with time when the ink droplets ejected from the nozzle 11 are arranged on the printing object 19 in a predetermined number of pieces. For this reason, it is necessary to adjust time from printing termination of the preceding longitudinal dot column to printing start of the succeeding longitudinal dot column. The non-charged droplets of α pieces which are not printed are added, as a used amount, to the respective longitudinal dot columns of the matrix character containing four lines, each of which is made up of longitudinal Y dots which is a column of printed dots made up of the ink droplets of Y pieces. In the case of FIG. 15 , the seven pieces of non-charged ink droplets, which are not printed out, are added to five pieces of the ink droplets to be used actually for the printing, which is handled as longitudinal dot columns, in relation to the matrix character made up of longitudinal five dots and transverse four lines’.
CITATION LIST
Patent Literature
PTL 1: International Application Publication No. WO02008/102458
SUMMARY OF INVENTION
Technical Problem
As mentioned above, according to the disclosure of Patent Literature 1, ink-jet printing (IJP) is performed with non-charged ink particles for adjustment inserted between charged ink particles. At this time, when negatively charged ink particles ejected from the nozzle pass through the deflecting electrode, the ink particles are deflected to the positive side of the deflecting electrode by electrostatic attraction so as to be printed on the printing object. However, there are some cases where such non-charged ink particles for adjustment might be electrostatically bonded to the negatively charged ink particles adjoining to such non-charged ink particles for adjustment, so that such non-charged ink particles for adjustment are positively charged. The problem with such cases lies in the fact that the ink particles for adjustment are deflected to the negative side of the deflecting electrode when they pass through the deflecting electrode so that they do not return to the gutter.
Further, according to the disclosure of Patent Literature 1, the total number of ink particles for one longitudinal column is determined through the method by which non-charged particles are inserted between charged particles (hereinafter, referred to as ‘the rate by which particles are used). At this time, as long as the conveying speed of the printing object is at a certain rate and there is a predetermined number of ink particles containing non-charged particles to be used for printing, theoretically, the interval between longitudinal columns results in being constantly the same as a result of ink-jet printing (IJP). However, when the conveying speed of the printing object changes, it is natural that such interval between the longitudinal columns subjected to ink-jet printing (IJP) changes.
In Patent Literature 1, only the case where the conveying speed of the printing object is at a certain rate is taken into account, but the situation where the travelling speed of the printing object accelerates or decelerates between the printing object detection sensor and the nozzle is not taken into due account, with the result that it is likely that such interval between longitudinal columns subjected to ink-jet printing (IJP) might fluctuate.
The present invention is to solve the abovementioned problem and to improve on printing quality as well as reliability with printing operation.
Solution to Problem
In order to solve such problem, the arrangements recited in the accompanying patent claims are adopted herein by way of some examples. The present invention contains a plurality of means to solve such problem, but one of them is presented as follows: an inkjet recording device comprising: an ink container for holding ink that is printed on a printing object; a nozzle that is connected to the ink container and discharges the ink; a charging electrode for charging a specified portion of the ink discharged from the nozzle; a deflecting electrode for deflecting the ink charged at the charging electrode; a gutter that collects the ink that is not used for printing; and a control unit that controls the printing, in which the control unit is characterized in controlling the ink particles that are adjoining to the ink particles used for the printing and are not used for the printing such that they are charged with the charging electrode.
Advantageous Effects of Invention
The present invention allows an inkjet recording device that improves on printing quality as well as reliability with printing operation to be provided.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a structural arrangement of an inkjet recording device according to first and second embodiments of the present invention.
FIG. 2 shows a structural arrangement of an inkjet recording device according to a third embodiment of the present invention.
FIG. 3 is a view showing the state where printing objects are carried when one printing object detection sensor is adopted for the inkjet recording device according to a first embodiment of the present invention.
FIG. 4 is a view showing the state where printing objects are carried when two printing object detection sensors are adopted for the inkjet recording device according to the second embodiment of the present invention.
FIG. 5 is a view showing the state where the printing object is carried when a rotary encoder is adopted for the inkjet recording device according to the third example of the present invention.
FIG. 6A-6D are views showing the relationship between the ink particles for adjustment and those for each longitudinal column to be charged according to the carrying speed of the printing object in the prior art.
FIG. 7A-7D are views showing the relationship between the ink particles for adjustment and those for each longitudinal column to be charged according to the carrying speed of the printing object based on the present invention.
FIG. 8 is a flow chart showing how to control the printing according to the first embodiment of the present invention.
FIG. 9 is a flow chart showing how to control the printing according to the second embodiment of the present invention.
FIG. 10 is a flow chart showing how to control the printing according to the third embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
The preferred examples for carrying out the present invention are described below with reference to the accompanying drawings.
(First Embodiment)
In FIG. 1 , the structural arrangement of the inkjet recording device according to the present example is shown, in which 101 denotes an MPU (Micro Processing Unit) to control the inkjet recording device as a whole, 102 denotes a RAM (Random Access Memory) to temporarily store data within the inkjet recording device, 103 denotes a ROM (Read Only Memory) to store software and data to compute a belt conveyor speed and a printing speed, 104 denotes a panel in which the length of a printing object, a printing distance, a position to start with writing and a width between columns in which characters are printed are input, 105 denotes a printing control circuit to control the printing operation of the inkjet recording device, 106 denotes a printing object detection circuit, 107 denotes a travelling speed measuring circuit to compute a belt conveyor speed based on the time required to detect the printing object and the input length of the printing object, 108 denotes a character signal generating circuit to render a printing content into a character signal, 109 denotes a bus to transmit data and so forth, 110 denotes a nozzle to eject the ink, 111 denotes a charging electrode to charge the ink particles derived from the ink ejected from the nozzle, 112 denotes a deflecting electrode to deflect the charged ink particles, 113 denotes a gutter to collect the ink that is not used for the printing, 114 denotes a pump to refeed the ink collected from the gutter to the nozzle, 115 and 116 denote sensors to detect the printing object, 117 denotes a printing object on which the printing is performed and 118 denotes a belt conveyor to carry the printing object thereon.
Then, a series of operations from imputing a printing content to completing the printing is explained as follows. The printing content can be set by inputting its data through the panel 104 so as to be preserved in the RAM 102 . Further, the total number of ink particles for one longitudinal column can be calculated with the following equation 1 based on the size of character to be printed, the width between columns in which characters are printed and the rate by which the ink particles are used that are input and set by the panel 104 .
Total Number of Ink Particles for One Longitudinal Column=(Longitudinal Number of Dots in Character+Width between Columns) multiplied by Rate by which Ink Particles are Used (Equation 1)
The printing time (T) per one longitudinal column can be calculated with the following equation 2 based on the calculated total number of ink particles for one longitudinal column and the cycle of the generated ink particles.
Printing Time per One Longitudinal Column=Total Number of Ink Particles for One Longitudinal Column/Exciting Frequency (Equation 2)
The maximum printing speed V can be calculated with the following equation 3 based on the calculated printing time per one longitudinal column and the distance between longitudinal columns (hereinafter, referred to as ‘dot pitch’).
Maximum Printing Speed V=Dot Pitch/Printing Time per One Longitudinal Column (Equation 3)
Then, with reference to FIGS. 3 , 6 and 8 , the difference between the prior art and the present invention is explained. FIG. 3 is a view showing the state where printing objects are carried when one printing object detection sensor is adopted for the inkjet recording device according to the present example whereas FIG. 6 is a view showing the relationship between the ink particles for adjustment and those for each longitudinal column to be charged according to the carrying speed of the printing object in the prior art. FIG. 7 is a view showing the relationship between the ink particles for adjustment and those for each longitudinal column to be charged according to the carrying speed of the printing object based on the present invention while FIG. 8 is a flow chart showing how to control the printing according to the present example.
FIG. 3 is a view showing the printing objects carried when one printing object detection sensor is adopted according to the first embodiment. As shown in FIG. 3 , the printing object 117 a is carried on the foremost position of the belt conveyor and the other printing objects 117 b and 117 c follow with a certain interval between them on the conveyor. Then, herein, the length in the carriage direction of the printing object is defined as L; and the distance from the printing object detection sensor 116 to the printing nozzle 110 is defined as S 1 . The present invention is intended for calculating the number of ink particles for one longitudinal column, the printing time, the travelling speed and acceleration of the printing objects and setting the number of ink particles for adjustment as well as performing the printing by the time when the printing objects travel from the printing object detection sensor 116 to the printing nozzle 110 and before the printing nozzle starts operating.
Hereupon, to begin with, the relevant prior art is explained with reference to FIG. 6 . FIG. 6 shows the relationship between the ink particles to adjust the width between columns in which characters are printed and the charged ink particles for printing the characters according to the conveying speed of the printing object. In FIG. 6 , FIG. 6( a ) shows a dot pattern of the ink particles for each longitudinal column for printing the character and a dot pattern of the ink particles to adjust the width between columns in which characters are printed; FIG. 6( b ) shows a charge signal of ink particles corresponding to such dot patterns; FIG. 6( c ) shows a printing timing signal for each longitudinal column according to the travelling speed of the printing object when it passes the printing object detection sensor 116 ; and FIG. 6( d ) shows a printing timing signal for each longitudinal column according to the travelling speed of the printing object when it passes the printing nozzle 110 .
With reference to FIGS. 6( a ) and 6 ( b ), as with the ink particles (five black filled circles) for one longitudinal column and those for adjustment (two white filled circles) at the left side as shown in FIG. 6( a ), seeing the charge signal (its vertical axis indicating the charge voltage) shown in FIG. 6( b ), it is found that the charge voltage of the lower dots to be printed is lower while such voltage gradually rises and two dots of the ink particles for adjustment determine the width with the subsequent longitudinal column. FIGS. 6( a ) and 6 ( b ) show dot patterns in which five vertical lines are printed. As with the printing timing shown in FIG. 6( c ), the printing is performed at a certain time t 1 without any acceleration arising when the printing object travels on the conveyor being taken into account. Thus, the printing timing corresponds to the pulse rising time of the charge signal of the ink particles shown in FIG. 6( b ). However, as shown in FIG. 6( d ), when acceleration arising when the printing object travels on the conveyor is taken into account, the cycle t′ of the printing timing for each longitudinal column according to the travelling speed of the printing object when it passes the printing nozzle is displaced with the cycle of the charge signal of the ink particles shown in FIG. 6( b ).
Accordingly, when the printing is performed, there arises slight inconsistency in the width between the columns in which characters are printed, so that the printing quality slightly deteriorates. Further, as shown in FIG. 6 , according to the travelling speed of the printing object which passes the printing object detection sensor, the number of non-charged ink particles for adjustment to be inserted is determined, but in the case where the printing object 117 a travels with acceleration during the lapse of time from when it passes the printing object detection sensor 116 to when it passes the printing nozzle 110 , such number of non-charged ink particles for adjustment has not been able to be altered in the prior art. Further, on account that the ink particles for adjustment are non-charged, when there exist charged ink particles in front of the inserted ink particles for adjustment, electrostatic bonding with the charged ink particles deprives electric charge of the non-charged ink particles for adjustment, so that when the ink particles for adjustment pass the deflecting electrode, such particles are deflected to the negative side of the deflecting electrode, with the result that they cling to the surroundings without returning to the gutter.
Then, how to control the printing with the acceleration of the printing object taken into account which is yet to be solved by the prior art is explained as follows. FIG. 8 is a flow chart showing how to control the printing according to the present example. With reference to FIG. 8 , in the first place, at S 1 , such printing contents and conditions as the type of characters to be printed, their size and the width between the columns in which they are printed are set. Then, at S 2 , the maximum printing speed is calculated with the equations 1, 2 and 3 based on the predetermined values. Subsequently, at S 3 and S 4 , based on the length of the respective printing objects and the time during which the printing objects shield the light emitted from the detection sensor 116 , the travelling speeds V 117 a and V 117 b of the printing objects 117 a and 117 b when they pass the printing object detection sensor 116 are calculated. At S 5 , based on the travelling speeds of the first and second printing objects 117 a and 117 b and the difference t 1 in timing in which those two printing objects are detected, the acceleration a of the printing object 117 b is calculated with the following equation 4.
Acceleration a =( V 117 a−V 117 b )/ t 1 (Equation 4)
Then, at S 6 , the following equations 5 and 6 are established correlatively among the calculated acceleration a of the printing object 117 b , the conveying speed V 117 b when the printing object 117 b passes the printing object detection sensor 116 and the distance S 1 between the sensor and the nozzle body 110 , according to which the travelling speed V′ when the printing object 117 b passes the nozzle body 110 is calculable.
S 1= V 117 b×t+ 0.5× at 2 (Equation 5)
V′=V 117 b+at (Equation 6)
Then, the number of ink particles for adjustment that are inserted or required according to the conveying speed V′ when the printing object 117 b passes the nozzle body 110 is found by calculating the following equation 7.
Travelling Speed V ′=Exciting Frequency×Dot Pitch/(Total Number of Ink Particles for One Longitudinal Column+Number of Ink Particles for Adjustment)×Rate by which Ink Particles are used (Equation 7)
Through the above calculation, the number of ink particles for adjustment calculated with the above equation 7 is determined.
Further, the ink particles for adjustment are inserted following the insertion of the predetermined ink particles for one longitudinal column, in which when there exist charged ink particles in front of those for adjustment, the ink particles for adjustment are electrified with a certain amount of electric charge of lower level according to the electric charge amount with which the ink particles in front of those for adjustment are charged (S 7 ). Electrifying the ink particles for adjustment with such electric charge of lower level allows electric charge amount to be set off between the ink particles for adjustment and the charged ink particles to be used for the printing positioned in front of the ink particles for adjustment even when there might arise electrostatic bonding between them, so that the ink particles for adjustment are rendered substantially into a non-charged state, with the result that the ink particles for adjustment are not deflected by the deflecting electrode or they are securely collected by the gutter. Then, the charged ink particles for the printing start printing according to their charge voltage (S 7 ).
Subsequently, the printing on the printing object according to the abovementioned printing control method is explained as follows with reference to FIG. 7 . FIG. 7 shows how to control the printing with the acceleration of the printing object taken into account, in details, showing the relationship between the ink particles for adjustment and the charged ink particles to be printed according to the travelling speed of the belt conveyor. With reference to FIG. 7 , FIG. 7( a ) shows a dot pattern of the ink particles for each longitudinal column for characters to be printed and a dot pattern of the ink particles to adjust a width between the columns in which the characters are printed; FIG. 7( b ) shows the charge signals of the ink particles according to such dot patterns; FIG. 7( c ) shows the printing timing signal for each longitudinal column according to the travelling speed of the printing object when it passes the printing object detection sensor 116 ; and FIG. 7( d ) shows the printing timing signal for each longitudinal column according to the travelling speed of the printing object when it passes the printing nozzle 110 . FIG. 7( a ) shows an example of dot patterns of the ink particles, in which it is exemplified that the printing according to such dot patterns make five vertical lines printed. The charge signals of the ink particles corresponding to the example shown in FIG. 7( a ) are shown in FIG. 7( b ).
The dot pattern of the ink particles for one longitudinal column at the left side of FIG. 7( a ) corresponds to the charge signal of the ink particles at the left side of FIG. 7( b ), in which the charge voltage of the lowest printing dot is lower while such voltage rises according as the printing dots go upwards. Then, when the printing at the fifth dot ends, there is one dot for the ink particles for adjustment, the number of which particles corresponds to the calculated number. Further, one dot of such ink particles for adjustment corresponds to the interval with the subsequent character (vertical line herein). Moreover, the charge voltage E is slightly applied to the ink particles for adjustment so as to make them electrified. This prevents the ink particles for adjustment from being not collected into the gutter, which is caused by the ink particles for adjustment being slightly electrified through electrostatic bonding with the charged ink particles when there exist such charged ink particles in front of the ink particles for adjustment. That is to say, against the charge voltage with which the ink particles for adjustment are electrified under the influence of the charged ink particles in front of them, those for adjustment are electrified with an opposite electric charge having the counterbalancing voltage, so that the electric charge of the ink particles for adjustment is rendered into zero so as to make them collected at the gutter.
Then, FIG. 7( c ) shows a printing timing signal for each longitudinal column according to the travelling speed of the printing object when it passes the printing object detection sensor, in which any acceleration of the printing object when the conveyor moves is not taken into account, so that such printing timing signal does not correspond to the timing of the charge signal of ink particles shown in FIG. 7( b ). On the other hand, the printing timing signal for each longitudinal column according to the conveying speed of the printing object when it passes the printing nozzle shown in FIG. 7( d ) corresponds to the timing of the charge signal of the ink particles shown in FIG. 7( b ) due to the fact that the acceleration of the printing object is taken into account when the conveyor moves. As mentioned above, according to the present invention, the printing quality enhances further than the prior art in such a manner that the printing is performed by calculating the acceleration of the printing object when the conveyor moves and the number of ink particles for adjustment to determine the width between the columns in which characters are printed based on the travelling speeds and so forth. Further, in the prior at, when there exist charged ink particles for the characters to be printed in front of those for adjustment or there exist those for adjustment after such charged particles, those for adjustment are slightly electrified by electrostatic bonding with such charged particles, so that they are not collected into the gutter. Enforcedly electrifying those for adjustment allows the electric charge amount to be set off between those for adjustment and such charged particles, so that the collectability with which those for adjustment are collected improves so as to permit the reliability with the printing operation to enhance.
(Second Embodiment)
Then, the carriage of the printing objects where two printing object detection sensors are provided according to the present invention is explained with reference to FIG. 4 . In FIG. 4 , it is shown that the printing object detection sensors 115 and 116 are disposed with a certain interval between them; and on the conveyor the printing object 117 a is carried in the forefront thereof and the printing object 117 b is disposed with a certain interval with the printing object 117 a as well as the printing object 117 c is further disposed with a certain interval with the printing object 117 b . Further, herein, the length of the printing objects in the carriage course to which they are carried is defined as L while it is defined that the printing objects pass for the passage time T between the printing object detection sensors. Moreover, herein, the distance from the printing object detection sensor 116 to the printing nozzle 110 is defined as S 1 .
How to control the printing according to the present example is explained as follows with reference to the flow chart illustrated in FIG. 9 . First of all, such printing contents and conditions as the type of characters to be printed, their size and the width between the columns in which characters are printed are set (S 10 ). Then, the maximum printing speed is calculated with the following equations 1 to 3 based on the predetermined values (S 20 ). Then, the travelling speeds V 115 a and V 115 b of the printing object 117 a at the first point (at the detection sensor 115 ) and the second point (at the detection sensor 116 ) are calculated based on the length of the printing object and the time during which the printing object 117 a shields the light emitted from the detection sensors 115 and 116 (S 30 , S 40 ), and the acceleration a of the printing object 117 a is found with the following equation 8 based on the passage time t 1 during which the printing object passes between those two detection sensors (S 50 ).
Acceleration a =( V 116 a−V 115 a )/ t 1 (Equation 8)
The travelling speed V′ of the printing object 117 a when it passes the printing nozzle 110 is calculable with the following equations 9 and 10 based on the calculated acceleration a of the printing object 117 a , the travelling speed V 116 a of the printing object when it passes the printing object detection sensor 116 and the distance S 1 between the detection sensor 116 and the printing nozzle 110 .
S 1= V 116 a×t+ 0.5 at 2 (Equation 9)
V′=V 116 a +at (Equation 10)
Then, the number of ink particles for adjustment that are inserted and required according to the travelling speed V′ of the printing object 117 a when it passes the nozzle 110 is calculable with the following equation 11.
Travelling Speed V ′=Exciting Frequency×Dot Pitch/(Total Number of Ink Particles for One Longitudinal Column+Number of Ink Particles for Adjustment)×Rate by which Ink Particles are used (Equation 11)
Through the above calculation, the number of ink particles calculated with the above equation 11 is determined.
Further, the ink particles for adjustment are inserted following the insertion of the predetermined ink particles for one longitudinal column, in which when there exist charged ink particles in front of those for adjustment, the ink particles for adjustment are electrified with a certain amount of electric charge according to the electric charge amount with which the ink particles in front of those for adjustment are charged (S 70 ). Then, the charged ink particles for the printing start printing according to their charge voltage (S 80 ).
Using two printing object detection sensors according to the above arrangement permits the acceleration of the printing object and the travelling speed of the printing object when it passes the printing nozzle to be calculated, in which the printing can be controlled in such a manner that the number of ink particles for adjustment, which are electrified with a certain amount of electric charge with electrostatic bonding with the charged ink particles additionally applied to the non-charged ink particles to be used according to the travelling speed of the printing object when it passes the printing nozzle, is increased or decreased. Thereby, the printing quality and the reliability with the printing operation enhance.
(Third Embodiment)
Then, the carriage of the printing object according to the present example in which such printing object is carried on the production line provided with a rotary encoder is explained as follows with reference to FIG. 5 . In FIG. 5 , after the printing object 117 is detected at the printing object detection sensor 115 , its travelling speed as well as its average periods a and b are calculated based on the predetermined pulse number and pitch between pulses of the rotary encoder 119 that are input from the encoder. As for how to find the travelling speed and acceleration of the printing object based on such average periods and how to find the number of ink particles for adjustment as required, it is described afterwards.
The structural arrangement of the inkjet recording device, in which the rotary encoder 119 according to the present example is provided, is shown in FIG. 2 . With reference to FIG. 2 , the same structural components as those shown in FIG. 1 are numbered with the same reference numerals as those shown in FIG. 1 and explanation is given below on the components differentiating the present example from that shown in FIG. 1 . Namely, in FIG. 2 , 115 denotes a sensor to detect a printing object; 117 denotes the printing object on which the printing is performed; 118 denotes a belt conveyor to carry the printing object 117 ; 119 denotes a rotary encoder disposed on the belt conveyor 119 to convert the movement of the belt conveyor into a pulse number; 120 denotes an input circuit of a pulsed signal of the rotary encoder 119 ; and 121 denotes a frequency divider to demultiply the pulsed signal of the rotary encoder are illustrated.
Then, how to control the printing according to the third embodiment is explained as follows with reference to the flow chart shown in FIG. 10 . In the first place, the printing contents desired to be printed and the printing conditions in harmony with carriage speed as well as the rotary encoder's output pulse number when it revolves once and the diameter of the encoder pulley are preliminarily set through the panel 104 so as to be preserved in RAM 102 (S 100 ). At this time, the pitch between encoder pulses is calculable based on such output pulse number and diameter of the encoder pulley. Based on the printing size, the rate by which ink particles are used, the width between the columns in which characters are printed, the number of dots for each longitudinal column to be used for the printing is calculable with the following equation 12.
Total Number of Ink Particles for One Longitudinal Column=(Longitudinal Number of Dots in Character+Width between Columns) multiplied by Rate by which Ink Particles are Used (Equation 12)
Based on the calculated total number of ink particles for one longitudinal column and the cycle of the generated number of ink particles, the printing time T per one longitudinal column is calculable with the following equation 13.
Printing Time per One Longitudinal Column=Total Number of Ink Particles for One Longitudinal Column/Exciting Frequency (Equation 13)
The maximum printing speed V can be calculated with the following equation 14 based on the calculated printing time per one longitudinal column and the dot pitch (S 200 ).
Maximum Printing Speed V =Dot Pitch/Printing Time per One Longitudinal Column (Equation 14)
Upon the printing object being carried on the production line provided with the rotary encoder (see FIG. 5 ), after the printing object is detected at the printing object detection sensor, its travelling speed as well as its average periods a and b are calculated based on the predetermined pulse number and pitch between encoder pulses of the rotary encoder 119 that are input from the encoder. Based on the calculated average periods, the conveying speed Va (S 300 ) is calculable with the following equation 15 while the conveying speed Vb (S 400 ) is calculable with the following equation 16 .
Travelling Speed Va =Travelling Distance/Average Period a ×Pulse Number (Equation 15)
Travelling Speed Vb =Travelling Distance/Average Period b ×Pulse Number (Equation 16)
Based on the measured difference in speed between the travelling speeds Va and Vb of the printing object 117 , the acceleration a (at s 500 ) of the printing object 117 is calculable with the following equation 17 using such difference and time measured by the rotary encoder 119 .
Acceleration a =( Vb−Va )/(Average Period a +Average Period b )×Pulse Number (Equation 17)
Based on the acceleration a of the printing object 117 , the travelling speed Vb derived from the calculated period b and the time t at which the printing object reaches the printing nozzle 110 , the travelling speed V′ of the printing object 117 when it passes the nozzle 110 is calculable with the following equation 18 (S 600 ).
V′=V b+a t (Equation 18)
Then, the number of ink particles for adjustment as required according to the travelling speed V′ of the printing object 117 when it passes the nozzle 110 is calculable with the following equation 19.
Travelling Speed V ′=Exciting Frequency×Dot Pitch/(Total Number of Ink Particles for One Longitudinal Column+Number of Ink Particles for Adjustment)×Rate by which Ink Particles are used (Equation 19)
Through the above calculation with the equation 19, the number of ink particulates for adjustment is determined. Further, the ink particles for adjustment are inserted following the insertion of the predetermined ink particles for one longitudinal column, in which when there exist charged ink particles in front of those for adjustment, the ink particles for adjustment are electrified with a certain amount of electric charge according to the electric charge amount with which the ink particles in front of those for adjustment are charged (S 700 ). Then, the ink particles for adjustment start printing according to their charge voltage (S 800 ).
Using the rotary encoder according to the above arrangement permits the acceleration of the printing object and the travelling speed of the printing object when it passes the printing nozzle to be calculated, in which the printing can be controlled in such a manner that the number of ink particles for adjustment, which are electrified with a certain amount of electric charge with electrostatic bonding with the charged ink particles additionally applied to the non-charged ink particles to be used according to the travelling speed of the printing object when it passes the printing nozzle, is increased or decreased. Thereby, the printing quality and the reliability with the printing operation enhance.
REFERENCE SIGNS LIST
101 : MPU (Micro Processing Unit)
102 : RAM (Random Memory Access Memory)
103 : ROM (Read Only Memory)
104 : panel
105 : printing control circuit
106 : printing object detection circuit
107 : travelling speed measuring circuit
108 : character signal generating circuit
109 : bus
110 : nozzle
111 : charging electrode
112 : deflecting electrode
113 : gutter
114 : pump
115 , 116 : printing object detection sensor
117 : printing object
118 : belt conveyor
119 : rotary encoder
120 : input circuit of pulsed signal of rotary encoder
121 : frequency divider of pulsed signal of rotary encoder | Provided is an inkjet recording device for performing print control by increasing or decreasing the number of adjustment ink particles, which are used according to the speed of the object being printed even when the movement speed of the object being printed is increasing or decreasing and which are uncharged particles carrying a fixed electrical charge that takes electrostatic bonding into consideration. The present invention is an inkjet recording device provided with an ink container for holding ink that is to be printed on the object being printed, a nozzle that is connected to the ink container and discharges the ink, a charging electrode for charging specified ink that has been discharged from the nozzle, a deflecting electrode for deflecting the ink charged by said charging electrode, a gutter for collecting the ink that is not used for printing, and a control unit for controlling the printing. The inkjet recording device is characterized in that the control unit performs control so that ink particles which are not used for printing and are adjacent to ink particles that are used for printing are charged by the charging electrode. | 1 |
BACKGROUND
1. Field of Invention
The invention relates generally to method and apparatus for forming a subsea wellbore. More specifically, the invention relates to forming a piling bore and a wellbore at respective designated locations subsea.
2. Description of Prior Art
Subsea drilling templates are sometimes located on the sea floor for drilling a cluster of wellbores in a confined area. Subsea drilling templates typically have a number of receptacles, also referred to as funnels, through which a well will be drilled. Using a floating drilling vessel, the operator may drill each well, cap it, then move to another. At a later date, a platform is generally installed over the template and a tie-back is installed between the wells and platform. Production tubing is then generally connected from the well to production trees installed at the platform.
SUMMARY OF THE INVENTION
Provided herein is an example of a template for use in forming a wellbore in a seafloor. In an example the template is made up of a frame, an annular wellbore alignment funnel coupled with the frame, an annular piling funnel substantially coplanar with the wellbore alignment funnel, and a coupling. The coupling of this embodiment is defined by an overlap between a portion of the frame and the piling funnel. A bore is in the overlap adapted to receive a main stud, so that when the main stud is selectively engaged in the bore, the piling funnel is coupled to the frame, and when the main stud is removed from the bore, the piling funnel is decoupled from the frame. Optionally, the portion of the frame overlapping the piling funnel is an elongated tang member and the portion of the piling funnel overlapped by the frame is a clevis member with a recess adapted to receive the tang member therein. The template may further have sidewalls on the clevis at lateral ends of the recess that extend along elongate sides of the tang member and may include vertical slots in the sidewalls. Alignment members are optionally included that extend laterally from elongate sides of the tang and project through the slots when the tang member is in the recess. The alignment members may be positioned to provide a contact force against the slot as long as the main stud is engaged in the bore. A cup may optionally be included that is on an upper end of the main stud adapted for engagement from a remotely operated vehicle. The piling funnel may in one example be a first piling funnel and the coupling can be a first coupling; in this example the template further includes a second piling funnel substantially coplanar with the wellbore alignment funnel and a second coupling defined by an overlap between a portion of the frame and the second piling funnel, a bore in the overlap, and a main stud, so that when the main stud is selectively engaged in the bore, the second piling funnel is coupled to the frame, and when the main stud is removed from the bore, the second piling funnel is decoupled from the frame. Alternatively, when a piling is inserted through an axial opening in the piling funnel and into the seafloor, and the piling funnel is decoupled from the frame, the piling funnel drops to the seafloor and beneath the frame.
Also described herein is a method of subsea operations. In the example method provided on a seafloor is a drilling template having a wellbore alignment funnel and a piling alignment funnel mounted in a frame. A drill bit is inserted through the wellbore alignment funnel, a wellbore is drilled, and a piling is inserted through the piling alignment funnel. The piling alignment funnel is decoupled from the frame. In the example method, the piling alignment may be lowered to the seafloor. Further, a platform above a surface of the sea can be set over the wellbore, where the piling is used to align the platform at a designated location. The method can further optionally include coupling the piling alignment funnel to the frame by a main stud that is engaged in a bore that intersects the piling alignment funnel and the frame, wherein the piling alignment is substantially parallel with an axis of the piling alignment funnel, and wherein the step of decoupling the piling alignment from the frame comprises disengaging the main stud from within the bore. In one example, the piling alignment funnel is decoupled from the frame while the piling remains inserted in the piling as the piling alignment funnel is dropped to the sea floor. In one example, horizontal alignment of the piling alignment funnel is maintained during the step of decoupling the piling alignment funnel from the frame thereby shielding the main stud from moment forces. Optionally, an alignment element is mounted onto the frame that slides within a vertically formed slot on the piling alignment funnel and maintains the horizontal alignment of the piling alignment funnel.
In another example embodiment, a template for use in forming bores on a seafloor is disclosed herein. In this example the template includes a frame on the seafloor, wellbore alignment funnels mounted to the frame, a piling alignment funnel, a means for selectively coupling the piling alignment funnel to the frame, and a means for retaining the piling alignment funnel in a plane that is substantially parallel with a plane in which the wellbore alignment funnels are disposed when the piling alignment funnel is coupled to the frame and when being decoupled from the frame. In this example, the means for selectively coupling the piling alignment funnel to the frame comprises a main stud that engages a threaded bore that vertically extends through a portion of the frame and a portion of the piling alignment funnel. Optionally, the portion of the frame is a tang member and the portion of the piling alignment funnel is a clevis member. In an alternate embodiment, the means for retaining the piling alignment funnel in a plane can be an alignment member on a lateral side of the frame that slides within a vertical slot provided on the piling alignment funnel.
BRIEF DESCRIPTION OF DRAWINGS
Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of an example embodiment of a drilling template in accordance with the present invention.
FIG. 2 is a side view of an example of drilling a wellbore through the template of FIG. 1 in accordance with the present invention.
FIG. 3 is a side partial sectional view of wellbores formed using the template of FIG. 1 in accordance with the present invention.
FIG. 4 is a perspective view of a drop away funnel in accordance with the present invention.
FIG. 5 is a side sectional view of a coupling for an embodiment of the drop away funnel of FIG. 4 in accordance with the present invention.
FIG. 6 is a perspective view of an embodiment of the drop away funnel of FIG. 4 with a piling inserted therein in accordance with the present invention.
FIG. 7 is a side view of a platform positioned on the seafloor using an embodiment of the piling of FIG. 5 in accordance with the present invention.
While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.
It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the improvements herein described are therefore to be limited only by the scope of the appended claims.
An example of a template 20 for aligning bores on a sea floor is shown in a perspective view in FIG. 1 . The template 20 of FIG. 1 includes a series of annular wellbore alignment funnels 22 shown in a substantially coplanar arrangement and connected to one another by a series of elongate frame members 24 . In the example of FIG. 1 , the frame members 24 define a frame 26 . In one example, the frame members 24 are structural members, such as I-beams, T-beams, channel members, and the like and can also be hollow and have a circular or rectangular cross section. In an example, the funnels 22 have a conical upward surface to define an upward-facing flange. A piling alignment funnel 28 is also shown in the example of FIG. 1 and mounted on an end of the frame 26 .
FIG. 2 shows in a side view an example of the template 20 having been landed on a wellhead 29 set in the sea floor 30 . Also shown is a drill string 32 being lowered towards the template 20 for forming a wellbore through the sea floor 30 . Optionally, a drilling vessel (not shown) may be used for providing the rotating drill string 32 . An annular collar 34 is optionally shown disposed within one of the funnels 22 and extending vertically upward from an upper end of the funnel 22 and for receiving a lower end of the drill string 32 therein. Referring now to FIG. 3 , illustrated in a side partial sectional view are wellbores 36 (in dashed outline) that extend from the sea floor 30 downward into a formation below the template 20 A. In FIG. 3 , the example of the template 20 A is shown having a second piling arrangement funnel 28 2 in addition to a first piling alignment funnel 28 1 . Similarly, piling bores 38 1 , 38 2 are shown formed in the formation 39 below the sea floor 30 and registering with the respective piling alignment funnels 28 1 , 28 2 . In one example of operation, after the piling bores 38 1 , 38 2 are formed, pilings 40 1 , 40 2 are inserted within the bores 38 1 , 38 2 .
FIG. 4 is a perspective view of an example of a coupling 42 that selectively mounts the piling alignment funnel 28 onto the frame 26 . In FIG. 4 , the example of the coupling 42 includes a tang member 44 ; which as shown extends from the frame 26 . The example tang member 44 is depicted engaging a clevis member 46 illustrated mounted on an end of the piling alignment funnel 28 . The example of the tang member 44 of FIG. 4 is generally elongate and includes generally parallel planar members that define opposing lateral sides of the tang member 44 . Further shown in the examiner of FIG. 2 are set screw 48 that project outward from an outer surface of each of the lateral sides. Slots 50 are shown vertically oriented along outer lateral sides of the clevis member 46 and in the example of FIG. 4 , formed to receive the set screws 48 therein. In an example embodiment, the set screws 48 are within the slots 50 when the piling alignment funnel 28 is engaged with the frame 26 . Also shown in FIG. 4 are horizontally disposed support ribs 54 that connect on one end to a lateral side of the clevis member 46 and extend partially around an outer circumference of the piling alignment funnel 28 . Also a cup 52 is shown mounted on an upper side of the tang member 44 and as will be described in further detail below is useful for disengaging the piling alignment funnel 28 from the frame 26 .
FIG. 5 is a side sectional view of an example of disengaging the coupling 42 so that the piling alignment funnel 28 may be decoupled from and lowered away from the frame 26 . As shown, a forward portion of the tang member 44 is profiled to have a reduced height proximate its terminal end that defines a downwardly-facing shoulder 56 . The profiled end of the tang member 44 fits within a recess 58 formed on an outer end of the clevis member 46 so that the shoulder 56 lands on an upward facing surface defined by a bottom of the recess 58 . The outer terminal ends of the recess 58 extend outward proximate to an outer lateral surface of the clevis member 46 and define side walls 60 in which the vertical slots 50 are formed. A main stud 62 is shown vertically intersecting the tang member 44 and in the example of FIG. 5 has a threaded portion on its lower end. The threaded portion engages a threaded bore 64 shown extending through a lower surface of the recess 58 in the clevis member 46 . Further illustrated in the example embodiment of FIG. 5 is that an upper end of the main stud 62 couples with the cup 52 such that engaging and rotating the cup 52 can selectively engage and disengage the main stud 62 from the bore 64 . In the example of FIG. 5 , the main stud 62 has been rotated out of engagement with the bore 64 so that the clevis member 46 can be vertically moved downward and away from the tang member 44 , thereby allowing disengagement of the piling alignment funnel 28 with the frame 26 .
FIG. 6 illustrates an example embodiment of the piling alignment funnel 28 vertically dropping away from the frame 26 in a side perspective view. In this example moment forces M F are exerted to the coupling 42 from the weight of the piling alignment funnel 28 . The moment forces M F may fluctuate during operations as contact with the piling 40 may cause the alignment funnel 28 to tilt with respect to the piling 40 . The engagement of the slots 50 and set screws 48 largely absorb the moment forces M F thereby shielding the main stud 62 from what can be damaging bending moments from the weight of the piling alignment funnel 28 . Moreover, strategic positioning of the set screws 48 and slots 50 shields the main stud 62 from the bending moments during disengagement of the piling alignment funnel 28 from the frame 26 . In an example, the set screws 48 and slot 50 are positioned so that the set screws 48 maintain contact with the slot 50 until a lowermost threaded portion of the main stud 62 has disengaged from an uppermost threaded portion of the threaded bore 64 . Still referring to FIG. 6 , the piling 40 is shown inserted within the piling alignment funnel 28 such that disengaging the piling alignment funnel 28 from the frame 26 allows the piling alignment funnel 28 to slide axially downward while still circumscribing the piling 40 .
FIG. 7 shows a side view of an example of a fixed platform 66 that shown having legs 68 whose lower ends are in contact with the sea floor 30 . Alignment tubulars 70 1 , 70 2 are shown coupled with the legs 68 that in the example of FIG. 7 are provided for positioning the platform 66 in a designated location and/or orientation with respect to the wellbores 36 . In the example of FIG. 7 , the alignment tubulars 70 1 , 70 2 engage the strategically positioned the pilings 40 1 , 40 2 to dispose the platform 66 at the designated location. Although the piling alignment funnels 28 1 , 28 2 are shown on distal ends of the template 20 A, the piling alignment funnels 28 1 , 28 2 may be disposed from the same or adjacent the sides of the template 20 A. Wellhead assemblies 72 are shown provided on an upper end of the platform 66 and that are in fluid communication with the wellbores 30 via risers 74 that extend from the wellbores 30 and up to the wellhead assemblies 72 . An advantage of disengaging the piling alignment funnels 28 1 , 28 2 from the rest of the template 20 A is that when the platform 66 is deployed, in the unintended axial forces transferred to the pilings 40 1 , 40 2 will not be transferred to the template 20 A and/or the risers 74 . As such, potential damage to the template 20 , 20 A and wellhead assemblies can be prevented by the optional step of decoupling the piling alignment funnels 28 1 , 28 2 from the rest of the template 20 , 20 A.
Still referring to FIG. 7 , an example of a remotely operated vehicle (ROV) 76 is schematically illustrated, wherein the ROV 76 includes mechanical arms 78 for performing functions subsea. A control line 80 may be used for control commands that can in turn direct the ROV 76 subsea so the ROV 76 may manipulate the cup 52 ( FIG. 5 ) and for enabling a remote and subsea decoupling of the piling alignment funnels 28 1 , 28 2 from the template 20 A. It necessarily follows that the ROV 76 can be used to decouple funnel 28 from template 20 of FIG. 1 . One of the advantages of the engagement of the main stud 62 is that disengaging the main stud from the threaded bore 64 can be accomplished with a lower torque than that might otherwise be required for couplings that exert an axial and a torsional force to retain the piling alignment funnels 28 to the frame 26 .
In one example of operation, an embodiment of the template 20 of FIG. 2 or template 20 A of FIG. 3 is set at a location on the seafloor 30 and a drill string 32 is used to form wellbores 36 into the seafloor 30 beneath the template 20 , 20 A as well as bores 38 , 38 1 , 38 2 , for insertion of pilings 40 , 40 1 , 40 2 . An ROV 76 can be deployed subsea for manipulating the coupling(s) 42 that releasably fasten the piling alignment funnel(s) 28 , 28 1 , 28 2 to the template(s) 20 , 20 A. As discussed above, unscrewing the main stud 62 allows the piling alignment funnel(s) 28 , 28 1 , 28 2 to vertically drop down from the template(s) 20 , 20 A and decouple the template(s) 20 , 20 A from the pilings 40 , 40 1 , 40 2 . As such, subsea deployment of the platform 66 can take place with reduced risk of damage to the template(s) 20 , 20 A or any other hardware that may be coupled with the template(s) 20 , 20 A. If the platform impacts the piling while the funnel is attached to the template, the impact can transfer through the funnel and damage the template or misalign the templates and interfere with tieback to the rig once in position. Thus an advantage exists by detaching the funnel from the template.
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims. | A template for use in positioning subsea wellbores that has a drop away funnel that extends laterally from the template. The drop away funnel is used to locate a piling adjacent the wellbores and is selectively detached from the template after installing the piling. A tang and clevis type assembly mounts the drop away funnel to the template, where the tang and clevis are coupled together with a main stud. The main stud is oriented substantially parallel with an axis of the drop away funnel; so that when the stud is removed, the drop away funnel can decouple from the template and slide axially downward along the piling. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to coupling, and in particular to a pin-joint coupling, wherein three or more interrelated components are connected together in articulated operative arrangement. The invention provides a facile means for removing one of the components without disturbing the operative relationship of the other components.
Gas insulated circuit breaker units of extremely high ratings can have three or more circuit interrupters arranged in series relationship. Each interrupter is provided with a pull-rod, with adjacent interrupter pull-rods being connected together for the synchronous operation of all of the interrupters. The gas insulated circuit breaker unit is assembled and adjusted in the factory and shipped as a unit to the site for installation. In the factory, it is usual to assemble each interrupter individually and adjust the position of its associated shock absorber and over-travel stop for proper stroke of its associated contact and also equalization of the angular motion of the operating crank about a vertical line through the axis of the shaft about which the crank pivots. An acceleration spring and its retainer is installed on each pull-rod and connected by coupling to the operating crank. The acceleration spring is adjusted to its proper compressed length for securing of the interrupter contacts. The adjustment of the spring is accomplished by removing the coupling, and removing or adding adjusting washers on the pull-rod so that the compressed length of the accelerating spring is adjusted to its proper value.
After the adjustment of each interrupter is made individually, the interrupters are connected together and inserted as a unit into the enclosure. Since it is most important that all contacts of the associated interrupters make and break simultaneously, the final adjustment of the connecting turn buckles must be made to ensure that all spring loads on all operative cranks reach their over-travel stops at the same time. After this is achieved, all turn buckle adjustments can be locked in place and should not thereafter be changed, either before or after delivery to the customer.
Interrupters are inserted into the tank from one end of the enclosure and removal from the enclosure is usually in the reverse order of insertion. It is essential that provision be made to disconnect interrupters from each other without disturbing either the final adjustment within the enclosure or the final adjustment of the pull-rods between interrupters.
It is the general subject of this invention to disclose a type of pin-joint coupling for three or more components which are interrelated and which not only accomplishes the joining of the related components but also permits disconnecting one component from another component without interrupting the adjusted relationship or operation of the components.
Another object of the present invention is to provide a pin-joint coupling arrangement which provides an articulated connection between components.
Still another object of the invention is to provide a relatively simple pin-joint coupling arrangement for a plurality of interrelated components which facilitates the releasing of one component from the other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a horizontal view of a gas insulated circuit breaker unit with parts broken away to show one interrupter and operating mechanism;
FIG. 2 is an enlarged detail view of a portion of the circuit interrupter shown in FIG. 1 showing the blast valve and main contact arrangement as well as the accelerating pull-rod connection;
FIG. 3 is a plan view of a pin-joint coupling arrangement shown in relationship to three interrelated components;
FIG. 4 is a side view of the pin-joint coupling arrangement of FIG. 3; and,
FIG. 5 is a modification of the pin-joint coupling arrangement of FIG. 3, wherein a five-component arrangement is shown in connected relationship.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a high voltage, gas insulated circuit interrupter 10 having in the particular instance four circuit interrupters, two of which 11 and 12 are shown disposed within a gas tight enclosure 14. The gas insulated breaker 10 is provided with an operator 15 which is operatively connected to an end box 16 in which mechanism is contained that operatively connect the operator 15 to the accelerating pull-rod 20 associated with the interrupter 11. The pull-rod arrangement 21 for the interrupter 12 is connected to the right end of the pull-rod 20 associated with the interrupter 11. In a similar manner, the next interrupter to the right of the interrupter 12 also has its pull-rod 22 connected to the right end of the pull-rod 21 associated with the interrupter 12. Then the last or rightwardlymost interrupter has its associated pull-rod 23 connected to the right end of the pull-rod 22. Thus, the operation of all the interrupters is synchronized so that the opening and closing of contacts of all interrupters can be accomplished simultaneously.
In general, each interrupter, such as the interrupter 11, is similar in operation and construction and, thus, a general description of the interrupter 11 will apply to all interrupters of the unit 10. The interrupter 11 includes a movable contact 26 which is movable into and out of engagement with a stationary contact 19. In FIG. 2, a blast valve 27 is displaceable to allow a blast of high pressure gas to be delivered via a U-shaped passage 28 to the arcing area for extinguishing the arc drawn between the contacts on an opening operation. Operation of the contact 26 and the blast valve 27 is effected by movement of a crank 29. The crank 29 is shown in a position after it has operated to move the contact 26 to open position and to release the blast valve 27 for return to its normal closed position. When the crank 29 is pivoted in the counterclockwise direction, a link 31 forces the contact 26 leftwardly into a closed position. At the same time, a cam notch 32 is moved into a position to the right of the displaceable tongue 33 in a latch body 34. Thus, with the crank 29 positioned leftwardly to the position indicated by the broken line 36, the movable contact 26 will have been moved to a closed position and the latch cam groove will be connected to the latch 34 in readiness for an opening operation of the contact 26 and of blast valve 27.
Movement of the crank 29 for operating the contact 26 to a closed position, or for the simultaneous operation of the contact 26 and the blast valve 27 to open positions, is effected by means of the pull-rod 20. The pull-rod 20 at its right end has a pivotal connection with the upper end of an operating crank 38. The operating crank 38 is secured to a horizontal shaft 39 on which the crank 29 and latch body 34 are mounted. The latch body 34 is mounted on the shaft 39 to rotate relative to the shaft. On the other hand, the crank 29 is secured to the shaft 39 so as to be driven by the rotation of the shaft. Thus, pivotal movement of the operating crank 38 in a counterclockwise direction will effect rotation of the shaft 39, which, in turn, causes the pivotal movement of the crank 29 in a counterclockwise direction moving the contact 26 to a closed position and coupling the notch 32 with the latch tongue 33. As the pull-rod 20 moves leftwardly to effect the closing of the contact 26, acceleration spring 41 mounted about the pull-rod 20 is compressed or charged for a subsequent operation in a contact opening movement. As shown in FIG. 1, pull-rod 20 extends to the left and is pivotally connected to a bell crank 42 within the end box 16. The opposite end of the bell crank 42 is pivotally connected to a vertical rod 43, the lower end of which is pivotally connected to an operating lever 44 of the operator 15.
As previously mentioned, it is desirable to assemble each individual interrupter, such as the interrupter 11, in the factory and there adjust the position of its associated shock absorber 45 and its over-travel stop 46 for the proper stroke of the contact 26 and equalization of the angular motion of the crank 38 about a vertical line which passes through the axis of rotation of the shaft 39. When assembling the interrupter, a spring retainer 47 is installed on the pull-rod 20 along with the acceleration spring 41. As viewed in FIG. 3, the pull-rod 20 is bifurcated and is pivotally connected to the upper end of the operating crank 38 by means of a tubular pin or bushing 49. In the assembly process, the spring retainer 47 and the spring 41 are assembled on the pull-rod 20 with the pull-rod then being connected to the upper end of the operating crank 38. This is accomplished by removing the coupling at a turn buckle 51 at the far left end of the pull-rod 20 which permits adjusting washers 52, spring retainer 47 and acceleration spring 41 to be slipped over the pull-rod 20. Thereafter the left end of the pull-rod 20 is inserted through a hole 53, FIG. 2, in a spring retainer 54, formed integrally with an interrupter shield 55. With this accomplished, the left end of the interrupter pull-rod 20 is coupled to a turn buckle 51, FIG. 1, for an operable connection to the operator 15.
To measure the compressed length of spring 41, the pull-rod 20 must be pulled leftwardly, as viewed in FIGS. 1 and 2, until crank 29 touches the over-travel stop 46. The compressed length of the acceleration spring 41 is adjusted to proper value by adding or subtracting washers 52.
After the adjustment of each interrupter is made individually, the turn buckles 51 can be assembled on the left-hand end of each of the pull-rods 20, 21, 22 and 23 to effectively couple all the pull-rods together. The interrupters are preferably arranged with the correct spacing between interrupters established as they would occur within the enclosure 14. With this condition obtained, the pull-rod 20 can be pulled leftwardly to thereby move all of the pull-rods leftwardly simultaneously to compress all of the accelerator springs which are similar to the accelerator spring 41 until the crank 29 of the interrupter 11 touches its over-travel stop 46. It has been found that when crank 29 of interrupter 11 touches its over-travel stop 46, there will be a gap of increasing magnitude at the corresponding point on the remaining interrupters as one proceeds to the right, FIG. 1. This is caused by the variable stretch within the elastic limit of the pull-rods which results from the fact that the pull-rod furthest to the right, as viewed in FIG. 1, is loaded by only one accelerating spring while each succeeding pull-rod to its left has one additional spring load added to it. Since it is most important that all contacts make and break simultaneously, the final adjustment of the turn buckles such as turn buckles 51 associated with the left end of each of the pull-rods 20, 21, 22 and 23 must be made to ensure that with all springs loaded or charged, all of the cranks 29 associated with each individual interrupter reach their over-travel stops 46 at the same time. After this condition is obtained, all turn buckles can be locked in place and should not thereafter be changed, either before or after delivery to a customer.
Since interrupters in the present arrangement are inserted into the tank or enclosure 14 from the right-hand end of the enclosure through a service door 58, it is essential that provision be made to disconnect the interrupters from each other without disturbing either the final adjustment within the interrupter or the final adjustment of the pull-rod between interrupters.
To this end, a novel pin-joint coupling 60 for three or more interrelated components is provided. As shown in detail in FIG. 3, the tubular pin 49 is constructed and arranged to act as a pin connection between the clevis or bifurcated right end of the pull-rod 20 and the operating crank 38. The tubular pin 49 is provided with an axial bore 62 which serves as a bearing for a pin 63 so that clevis or bifurcated end 64 on the left end of the pull-rod 21 can be secured or released from the pull-rod 20 and crank 38 without disturbing the state of compression of the acceleration spring 41 or the adjustment of spring 41, shock absorber 45, over-travel stop 46, or the length adjustment of pull-rods 20 or 21.
To reduce friction between the outside of the tubular pin 49 and crank 38 and clevis 61, and between the wall of the bore 62 of the tubular pin 49 and pin 63, the pin-bushing 49 may be coated on the inside and outside with teflon or it may be made of sintered metal impregnated with a lubricant.
The pin 63 may be locked in place by locking clips or other suitable retainers, or may be threaded into the clevis of the coupling 64. However, it has been found that the accelerating springs 41 through the associated pull-rods apply sufficient force on the pin-bushing 49 and clevis 61 to maintain these members in place with crank 38 while pin 63 is withdrawn and no other securing means is necessary.
In FIG. 5, a modification of the pin-joint coupling of FIG. 3 is disclosed. The arrangement in FIG. 5 discloses how a greater number of interrelated components can be pinned together to provide for removal of components one at a time without disturbing the adjustment of the remaining components and making it possible to continue to operate the remaining components after such removal. As there shown, five components are shown pinned into a single coupling arrangement, each component comprising two identical members spaced apart. Thus, the central component such as a crank 71 is pivotally connected to a pair of arm members 72A and 72B of a single component 72. This connection is effected by means of a pin-bushing 73 having an axial bore. The two components 71 and 72 are shown connected to a pair of arm members 74A and 74B of a single component 74 by means of a pin-bushing 76 that extends through the arms 74A and 74B and through the bore of the pin-bushing 73. Thus, an articulate connection between the components 71, 72 and 74 is effected by means of the pin-bushings 73 and 76. In a similar manner, a pair of arm members 77A and 77B of a single component 77 are connected to the components 71, 72 and 74 by means of another pin-bushing 78 which extends through the arms 77A and 77B and through the bore of the tubular pin-bushing 76. In a similar manner, component 79, having a pair of spaced apart arm members 79A and 79B, is connected to the components 71, 72, 74 and 77 by means of a pin 81 that extends through the arms 79A, 79B and through the bore of the pin-bushing 78. It can be seen that the release of the component 79 is easily accomplished by simply removing the pin 81 to release the connection between the assembly and the component 79 without disturbing the operating arrangement of all the remaining connected components. This arrangement holds true for the component 77 which may be detached from the remaining assembled components by removal of the pin-bushing 78.
The novel pin-joint coupling for three or more interrelated components is extremely simple in its constructional arrangement but it is particularly efficient in its application, especially in the environment of the gas insulated circuit breaker units such as the unit 10 disclosed in FIG. 1. This is true because access to the interior of the enclosure 14 and to each interrupter is through portholes such as the portholes 82, 83 and 84 and through a similar porthole (not shown) associated at the interrupter 11. With the interrupters assembled in position within the enclosure 14 access for inserting the pin-joint couplings into operative position is only available through the ports 82, 83 and 84. Because of this limited access, the novel pin-joint coupling facilitates the connection of the pull-rods to each other and the pull-rod with its associated operating crank. It is also true that the pin-joint coupling provided herein makes it unnecessary to provide wrenches or other tooling for effecting the connection between the pull-rods, and the pull-rods and the operating cranks, thereby eliminating the danger of accidental dropping of such tooling into the interior of the enclosure 14 which would then require disassembly of the unit to retrieve the tooling. | A plurality of coaxial pins are cooperatively arranged to provide a pin-joint coupling for three or more interrelated components and provide the capability of removal of one component without disturbing the adjustment and operation of the other components. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to an electrically conductive material, a production method for the electrically conductive material, and a bioelectrode.
BACKGROUND ART
[0002] In the field of medical engineering, which is a combination of medical science and engineering, production of alternative devices substituting for physical functions is a challenge being tackled extensively. The production of such devices requires, first and foremost, accurate measurement of biopotentials including, for example, a myoelectric potential. The myoelectric potential may be measured within a subject muscle, as well as from outside of the subject muscle. Such a measurement within a muscle may enable more accurate reproduction of a muscle movement.
[0003] In view of this, the present inventor developed a conductive fiber usable as a flexible electrode which is capable of following the movement of a muscle and arranged within the muscle to measure a potential. This conductive fiber is produced by coating a fiber such as a silk fiber that is a biomaterial, with a conductive polymer (see, for example, Patent Documents 1, 2, or Non-Patent Document 1).
[0004] The conductive fiber described in each of Patent Document 1 and Non-Patent Document 1 includes poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT-PSS) as a conductive polymer, and is produced by a so-called electrolytic polymerization method. Specifically, according to the electrolytic polymerization method, the conductive fiber is produced in the following manner: A base fiber immersed in a conductive solution containing PEDOT-PSS is allowed to travel between, and be energized by, electrodes while being lifted vertically from the conductive solution, thereby electrochemically polymerizing and fixing the PEDOT-PSS that has been applied to the base fiber. The conductive fiber of Patent Document 2 includes PEDOT-PSS as a conductive polymer and is produced in such a manner that a resin composition as a mixture of PEDOT-PSS and a binder resin is applied to a base fiber, and then solidified or polymerized by drying, warming, or heating, for example.
[0005] Note that poly(3,4-ethylene-dioxythiophene)-p-toluenesulfonate (PEDOT-pTS) is known as a conductive polymer which has a higher conductivity than PEDOT-PSS (see, for example, Non-Patent Document 2).
CITATION LIST
Patent Document
[0000]
Patent Document 1: International Publication No. WO 2013/073673
Patent Document 2: Japanese Unexamined Patent Publication No. 2014-108134
Non-Patent Document
[0000]
Non-Patent Document 1: S. Tsukada, H. Nakashima, K. Torimitsu, “Conductive polymer combined silk fiber bundle for the bioelectrical signal recording,” PLoS ONE, 2012, Vol. 7, e33689-1-10
Non-Patent Document 2: Seul Gi Kim, Jong-Won Yang, Jun-Taek Lee, Jin-Yeol Kim, “Highly conductive PEDOT: PTS films interfacially polymerized using electro spray deposition and enhanced by plasma doping,” Japanese Journal of Applied Physics, 2014, 53, 035501-1-7
SUMMARY OF THE INVENTION
Technical Problem
[0010] The conductive fibers of Patent Documents 1, 2 and Non-Patent Document 1 are pleasant to the touch, highly durable and highly water-resistant, and also have flexibility. Therefore, these fibers may be used as, for example, an electrode arranged within a muscle to measure a potential. However, each of these conductive fibers of the known art, which has the conductive polymer, namely PEDOT-PSS, sparsely applied to the surface of the base fiber, and therefore, has a relatively high resistance value and causes an increased noise when used as an electrode.
[0011] In view of the foregoing background, it is therefore an object of the present invention to provide an electrically conductive material which includes a conductive polymer uniformly applied to the surface of a base fiber and has a reduced resistance value, a production method for such an electrically conductive material, and a bioelectrode.
Solution to the Problem
[0012] To achieve this object, an electrically conductive material according to the present invention includes: a base selected from the group consisting of a silk fiber, a fiber containing sericin or fibroin, and a fiber coated or soaked with sericin or fibroin; and poly(3,4-ethylene-dioxythiophene)-p-toluenesulfonate (PEDOT-pTS) applied to the base. As used herein, the expression “applied to the base” refers to being applied to the surface of the base, the inside of the base, and both on the surface and inside the base.
[0013] In summary, the material for forming the base is not limited to any particular material as long as the material contains sericin or fibroin. The material may be silk that contains these proteins by nature, or a material to which these proteins are added artificially.
[0014] The material allowed to contain, or be coated or soaked with, sericin or fibroin may be selected from a broad variety of materials, examples of which include: synthetic fibers such as a polyamide fiber, a polyester fiber, an acrylic fiber, an aramid fiber, a polyurethane fiber, and a carbon fiber; vegetable fibers such as a cotton fiber, a linen fiber, and a jute fiber; animal fibers such as the silk fiber descried above, wool, and a collagen fiber; and a fiber blend containing two or more of these fibers. The fiber may be colored.
[0015] Among these fibers, the silk fiber or a fiber containing silk as a major ingredient is beneficially selected. This is because silk contains sericin or fibroin by nature, has a good affinity for PEDOT-pTS and a high adhesiveness, and possesses a good affinity for a living body and a high strength. This “silk fiber or fiber containing silk as a major ingredient” is the “silk fiber” described above. The silk fiber may be made of silk alone or may be configured as a fiber blend containing silk and other fibers as necessary. As used herein, “other fibers” may be the synthetic fibers, the vegetable fibers, and the animal fibers excluding the silk fiber that have been listed above as examples of the material allowed to contain, or to be coated or soaked with, sericin or fibroin. The silk may be obtained from ordinary domestic silkworms, wild silkworms, or may be made of natural silk deriving from spiders, bees or wasps. Alternatively, the silk fiber may also be obtained by the gene recombination technology. Examples of such recombinant silk include “luminous silk” obtained from a silkworm in which a gene coding a fluorescent protein has been incorporated.
[0016] The base is beneficially “linear” or “planar.” Being linear refers herein to, for example, having the shape of a thread or a cord, or a vascular bundle having the shape of a fabric or a ribbon. Being planar refers herein to, for example, having the shape of a fabric, a film, a membrane, or a sheet. Apart from the “linear” and “planar” bases, a “gel” base may also be used. A typical example of the linear base is a thread, and a typical example of the planar base is a woven fabric (such as a plain woven fabric or a satin woven fabric).
[0017] In the electrically conductive material of the present invention,
[0000] (a) if the base is made of a linear member, a conductive portion of the base suitably has an electrical resistance value of 50 kΩ/cm or less, and more suitably of 1.6 kΩ/cm or less, in a cross-sectional area of about 2.5×10 −4 cm 2 , and
(b) if the base is made of a member with a different shape from that described in (a), such as a planar member, the conductive portion of the base suitably has an electrical resistance value of 50 kΩ/cm or less, and more suitably of 1.6 kΩ/cm or less.
[0018] As used herein, the “conductive portion” refers to a portion of the base subjected to an electroconductive treatment, specifically a portion having PEDOT-pTS applied thereto. If PEDOT-pTS is applied to only a portion of the base, that PEDOT-pTS applied portion corresponds to the “conductive portion.”
[0019] Regarding the situation (a) mentioned above, as will be described later with respect to examples, the electrical resistance value of the linear electrically conductive material of the present invention is obtained by measuring its electrical resistance per linear length of 1 cm using a tester. The cross-sectional area of about 2.5×10 −4 cm 2 is that of a silk thread having a standard diameter. As used herein, “about” means that “2.5” is given by rounding off the figure to one decimal place. Since the cross-sectional area is inversely proportional to a resistance value, it is easy to calculate a resistance value according to the cross-sectional area. It is expected that the cross-sectional area of PEDOT-pTS increases as the cross-sectional area of a linear base increases. This allows easy comparison between the electrically conductive materials of the present invention or between the electrically conductive material of the present invention and another electrically conductive material. Thus, the cross-sectional area is an appropriate parameter in determining the electrical resistance value in the present invention. If the conductive portion of the electrically conductive material has a length of less than 1 cm, then the electrical resistance value of the entire conductive region of the linear electrically conductive material is measured, and then converted into that of a portion having a length of 1 cm and the above cross-sectional area. Then, the comparison may also be made between them.
[0020] Regarding the situation (b) mentioned above, if the base has a nonlinear shape, typically, if the base is made of a planar member such as a fabric, the resistance value cannot be determined based only on the cross-sectional area of the base. However, in general, according to comprehensive resistance conversion of conductors based on their cross-sectional area, a planar member has a larger cross-sectional area than a linear member. Therefore, if the base has a nonlinear shape, the electrical resistance value per length of 1 cm of the conductive portion is determined as “the electrical resistance value per centimeter (Ω/cm or kΩ)/cm).” Based on this premise, a suitable range and an optimal range of the linear member described above with respect to the situation (a) may be determined as a feature of the electrically conductive material of the present invention.
[0021] A silk fabric of the example to be described later with reference to FIG. 8 had ten square electrode elements (each 1 cm×1 cm), each having an electrical resistance value of less than 1.6 kΩ/cm, which proves the validity of the above-described premise. Like the linear base, if the conductive portion of the electrically conductive material has a length of less than 1 cm, the electrical resistance of the conductive region of the electrically conductive material is measured, and then converted into that of a portion having a length of 1 cm. Then, the comparison may also be made between them.
[0022] A method for producing an electrically conductive material of the present invention includes the following steps (1) and (2):
[0023] (1) applying a p-toluenesulfonate (pTS) solution containing an oxidant component and pTS to a base selected from the group consisting of a silk fiber, a fiber containing sericin or fibroin, and a fiber coated or soaked with sericin or fibroin; and
[0024] (2) further applying 3,4-ethylenedioxythiophene (EDOT) to the base that already has the oxidant component and pTS applied thereto through the step (1), thereby triggering, at the base, a polymerization reaction to form poly(3,4-ethylene-dioxythiophene)-p-toluenesulfonate (PEDOT-pTS) and applying the formed PEDOT-pTS to the base.
[0025] The step (1) beneficially includes applying the oxidant component and pTS onto the base by either immersing the base in the pTS solution or printing the pTS solution on the base.
[0026] The step (2) suitably includes facilitating the polymerization reaction to form the PEDOT-pTS by heating the pTS solution while applying the EDOT onto the base. It is beneficial to perform, after the step (2), the process step of washing and drying the base to which the PEDOT-pTS has been applied. The base is beneficially washed with water, more beneficially with distilled water or deionized water. The base may be dried in a thermostatic oven, with hot air or warm air, or in the sun. Although drying in the sun is exemplified, it is beneficial to dry the base in a thermostatic oven or with hot or warm air. The thermostatic oven is suitably set at a temperature of 50-80° C., and more suitably at a temperature of 60-70° C. for drying the base. If hot or warm air is used, the surface temperature of the target is also suitably at 50-80° C., and more suitably 60-70° C.
[0027] Note that pTS and EDOT are both commercially available.
[0028] The method for producing the electrically conductive material of the present invention allows PEDOT-pTS, which has a higher degree of conductivity than PEDOT-PSS, to be applied to a base more uniformly and more evenly than the electrolytic polymerization method of the known art, thus achieving a significant reduction in the electrical resistance value of the electrically conductive material. Therefore, when used as an electrode, the electrically conductive material of the present invention may produce a reduced noise. The electrically conductive material produced by the production method according to the present invention has the electrical resistance value described above.
[0029] The electrolytic polymerization method of the known art allows almost no PEDOT-pTS to be applied to the surface of a base, and therefore, is unable to turn the surface of the base into an electrically conductive one. In contrast, the method for producing the electrically conductive material of the present invention allows PEDOT-pTS to be applied to the surface of a base uniformly and evenly. As can be seen, the production method of the present invention is suitable for producing the electrically conductive material of the present invention, and may produce the electrically conductive material that has a high degree of electrical conductivity and a lower resistance value.
[0030] Note that if PEDOT-PSS were used as the conductive polymer, even the method for producing the electrically conductive material of the present invention could not apply PEDOT-PSS to the base uniformly and evenly. Thus, employing PEDOT-PSS as the conductive polymer would make it difficult to produce an electrically conductive material having a lower resistance value than that produced by the electrolytic polymerization method of the known art.
[0031] The base for use in the electrically conductive material of the present invention and for the method for producing the electrically conductive material of the present invention is suitably degummed with an enzyme (mainly a protease), an acid, or an alkali.
[0032] In the method for producing the electrically conductive material of the present invention, the solution is suitably heated at 50-100° C. for 10-60 minutes, more suitably at 50-80° C. for 10-40 minutes, and even more suitably at 60-80° C. for 10-30 minutes. This heating allows PEDOT-pTS to be applied to the surface of the base faster and more densely, and achieves a further reduction in the resistance value. Further, in the method for producing the electrically conductive material of the present invention, the oxidant component suitably includes transition metal ions. Specifically, the oxidant component suitably includes iron ions, cerium ions, or molybdenum ions, and particularly suitably includes ferric ions. These ions enable efficient formation of PEDOT-pTS.
[0033] A bioelectrode according to the present invention includes the electrically conductive material of the present invention.
[0034] The bioelectrode includes an element made of the electrically conductive material of the present invention. The element may be designed for a surface electrode or a puncture electrode, for example.
[0035] A surface electrode is configured to derive an action potential or a brain wave which has been transmitted via capacity conduction, either through the skin or directly from the surface of a muscle, a brain, or any other organ (such a surface may be hereinafter referred to as “a living body tissue surface”), without having to be needled. The surface electrode is a bioelectrode which is attached to the subject's abdominal muscle or head when it is used. The surface electrode may be configured as an electrode for deriving an evoked potential or as a therapeutic stimulating electrode.
[0036] If the electrode of the present invention is configured as such a surface electrode, the electrode includes an electrode element, of which the area contactable with a body tissue surface suitably ranges from 0.0004 cm 2 to 100 cm 2 , more suitably from 0.0004 cm 2 to 25 cm 2 . Although an electrode having a contactable area of larger than 25 cm 2 may also be used as a surface electrode, such an electrode insufficiently takes advantage of a feature of the present invention, that is, “the capability of suitably deriving an action potential, an evoked potential, and a brain wave even with an electrode element having a significantly reduced area contactable with a body tissue surface.” A contactable area of smaller than 0.0004 cm 2 would make it difficult to derive an action potential, an evoked potential, or a brain wave sufficiently. However, if electromyograph systems and electroencephalograph systems have their performance enhanced in the future, an electrode having a contactable area of smaller than 0.0004 cm 2 could also be used suitably as a surface electrode.
[0037] Note that the “area contactable with a body tissue surface” refers herein to the area which is included in the electrically conductive material used as an electrode element for a surface electrode, and which is contactable with a body tissue surface. For example, if the electrode element is planar, the area of the sheet-like electrode element corresponds to the area contactable with the body tissue surface. In the case of such a planar electrode element, in particular, the contactable area suitably ranges from 0.25 cm 2 to 100 cm 2 , and more suitably from 0.25 cm 2 to 25 cm 2 . If the electrode element is linear, a half of the surface area of the linear electrode element to be in contact with a body surface corresponds to the area contactable with the body tissue surface. The surface area may be approximated, for example, as “the area of a rectangle” one side of which has its length defined by the diameter of the linear material and another side of which has its length defined by the length of the portion to be in contact with the body surface. In the case of such a linear electrode, in particular, the contactable area suitably ranges from 0.0004 cm 2 to 0.02 cm 2 , and more suitably from 0.0004 cm 2 to 0.005 cm 2 . Even if the electrode element has a different shape, the electrode element also has an area which may actually be in contact with the body tissue surface and which could be easily determined by those skilled in the art. The contactable area refers herein to the contactable area of a single independent electrode element. For example, if a plurality of electrode elements are arranged separately from each other in a single surface electrode, the contactable area refers to the contactable area of each of those electrode elements.
[0038] A puncture electrode literally refers herein to an electrode which is brought into contact with a living body by puncture, and derives a desired biological signal. Examples of the puncture electrode include a needle electrode and a wire electrode. The puncture electrode may be configured as an electrode for deriving an evoked potential or as a therapeutic stimulating electrode. The element of the bioelectrode configured as the puncture electrode suitably has an area contactable with a living body tissue ranging from 0.0004 cm 2 to 0.02 cm 2 , and more suitably from 0.0004 cm 2 to 0.002 cm 2 . For a puncture electrode, this contactable area is significantly smaller than contactable areas of the known art. Nevertheless, the electrode of the present invention may still effectively serve as a bioelectrode thanks to its high conductivity.
[0039] The electrically conductive material of the present invention, which has a low electrical resistance value, is pleasant to the touch, highly durable and highly water-resistant, and also has flexibility, may be suitably used as a bioelectrode. In particular, the base made of a biomaterial such as a silk fabric and a silk thread allows the electrically conductive material to be suitably used as a bioelectrode. The bioelectrode according to the present invention may be used as an electrode for measuring a potential within a muscle or an electrode for electrocardiogram, for example. As will be described later with respect to examples, the bioelectrode according to the present invention is implementable as a multipoint electrode including two or more electrode elements arranged on a single carrier (e.g. a fabric), which is one of beneficial exemplary embodiments of the present invention.
Advantages of the Invention
[0040] The present invention provides an electrically conductive material which includes a base and a conductive polymer applied uniformly and evenly to the surface of the base and has a reduced electrical resistance value. The present invention also provides a producing method for such an electrically conductive material and a bioelectrode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 shows a chemical reaction formula representing the formation reaction of PEDOT-pTS in a method for producing an electrically conductive material according to an embodiment of the present invention.
[0042] FIG. 2 is a graph showing respective electrical resistance values of electrically conductive materials including bases (silk threads) degummed in different ways, and produced by a method for producing an electrically conductive material according to an embodiment of the present invention.
[0043] FIGS. 3A-3E are electron micrographs of respective electrically conductive materials produced by a method for producing an electrically conductive material according to an embodiment of the present invention. FIG. 3A shows a raw silk thread, and FIG. 3B-3E show silk threads degummed with soap, a soaping agent, phosphoric acid, and an enzyme, respectively.
[0044] FIG. 4 is a graph showing electrical resistance values of an electrically conductive material produced by a production method (chemical polymerization method) according to an embodiment of the present invention and of an electrically conductive material produced by an electrolytic polymerization method.
[0045] FIGS. 5A and 5B are electron micrographs of an electrically conductive material produced by the electrolytic polymerization method, and an electrically conductive material produced by a production method according to an embodiment of the present invention (chemical polymerization method), respectively.
[0046] FIGS. 6A and 6B are micrographs showing the brain cells of a chick embryo cultured on a cover glass, and observed under ordinary light and fluorescence, respectively. FIGS. 6C and 6D are micrographs showing the brain cells of a chick embryo cultured on a cover glass coated with PEDOT-pTS for use in a method for producing an electrically conductive material according to an embodiment of the present invention, and observed under ordinary light and fluorescence, respectively.
[0047] FIG. 7A schematically shows how a potential is measured using an electrically conductive material according to an embodiment of the present invention within a muscle of a chick embryo. FIG. 7B is a graph showing a potential measured in the muscle using an electrically conductive material according to an embodiment of the present invention.
[0048] FIG. 8 Portion (a) of FIG. 8 schematically shows a multipoint electrode including the electrically conductive material according to an embodiment of the present invention. Portion (b) of FIG. 8 schematically shows the multipoint electrode attached to a subject. Portion (c) of FIG. 8 is a graph showing potential variations caused by motion and measured on the surface of actual skin.
[0049] FIG. 9 Portion (a) of FIG. 9 schematically shows a multipoint electrode including the electrically conductive material according to an embodiment of the present invention and designed for brain wave measurement. Portion (b) of FIG. 9 schematically shows the multipoint electrode attached to the surface of the brain of a chick embryo. Portion (c) of FIG. 9 is a graph showing a brain wave potential measured on the surface of an actual brain.
DESCRIPTION OF EMBODIMENTS
[0050] Embodiments of the present invention will now be described with reference to the drawings.
[0051] FIGS. 1-9 show electrically conductive materials according to embodiments of the present invention, and methods for producing the electrically conductive materials.
[0052] The electrically conductive material according to each embodiment of the present invention includes a base and PEDOT-pTS applied to the base. The electrically conductive material is produced by one of the production methods according to first and second embodiments of the present invention which will be described below.
[0053] Specifically, according to the first embodiment of the present invention, the method for producing the electrically conductive material includes, first, (1) dissolving an oxidant component and pTS as a dopant in an organic solvent-based solution and immersing a silk fabric or a silk thread serving as a base into the organic solvent-based solution.
[0054] An organic solvent which allows pTS, an oxidant component, and other components to be dissolved therein is used as the solvent for pTS. The organic solvent for pTS suitably has good compatibility with an aqueous solvent. Specifically, examples of the organic solvents include monovalent lower alcohols with the number of carbon atoms of 1 to 6: namely, methanol, ethanol, propyl alcohol, isopropyl alcohol, butanol, pentanol, and hexanol. The carbon atoms forming each of these monovalent lower alcohols may form a linear skeleton, a branch skeleton, a cyclic skeleton, or a combination of two or more of these skeletons. Each monovalent lower alcohol may be diluted with water, as appropriate, before being used. Among these alcohols, a monovalent lower alcohol with the number of carbon atoms of 1 to 4, namely, methanol, ethanol, propyl alcohol, isopropyl alcohol, or butanol is suitably used as the organic solvent for the pTS solution.
[0055] The oxidant component contained in the pTS solution is not limited to any particular substance as long as the oxidant component is capable of activating the polymerization reaction through which pTS and EDOT in contact with each other are polymerized into PEDOT-pTS. Examples of the oxidant components include transition elements and halogens.
[0056] Examples of the transition elements include: elements of the first transition series such as iron, titanium, chromium, manganese, cobalt, nickel, and zinc; elements of the second transition series such as molybdenum, silver, zirconium, and cadmium; and elements of the third transition series such as cerium, platinum, and gold. Among these elements, the elements of the first transition series such as iron and zinc are used suitably.
[0057] The oxidant component content of the pTS solution varies depending on the type of the oxidant component to be used, and is not limited to any particular content as long as the above-described polymerization reaction can be activated with the oxidant component content. For example, in the case of ferric ions (Fe 3+ ) used in an example described herein, they are suitably blended, in the form of ferric chloride, at a ratio of 1-10% by mass, and more suitably at a ratio of 3-7% by mass, with respect to the pTS solution. An excessive amount of ferric chloride blended in the solution would accelerate the polymerization reaction, but would make it difficult to remove iron in a later process step. An insufficient amount of ferric chloride would delay the polymerization reaction.
[0058] The content of pTS functioning as a dopant in the pTS solution is suitably 0.1-10% by mass, more suitably 0.15-7% by mass, even more suitably 1-6% by mass, and most suitably 2-5% by mass with respect to the solution.
[0059] Next, (2) after EDOT monomers are added to the solution, the solution is heated suitably at 50-100° C. for 10-60 minutes, more suitably at 50-80° C. for 10-40 minutes, and even more suitably at 60-80° C. for 10-30 minutes. After this heating, the base is taken out of the solution, and washed beneficially with water, more beneficially with distilled water or deionized water. Thereafter, the base is dried in a thermostatic oven, with hot air or warm air, in the sun, or in other manners. At room temperature, EDOT is in a liquid state and soluble in water, and may be diluted in an aqueous solvent such as water as appropriate before being used.
[0060] The ratio between the amounts of the pTS solution and EDOT (pTS solution:EDOT) in terms of volume ratio ranges from 10:1 to 100:1, and suitably from 20:1 to 40:1.
[0061] According to the second embodiment of the present invention, the method for producing the electrically conductive material includes, first, (1) dissolving an oxidant component and pTS as a dopant in an organic solvent-based solution, and print the organic solvent-based solution on a base.
[0062] An organic solvent which allows pTS, an oxidant component, and other components to be dissolved therein is used as the solvent for pTS. The organic solvent for pTS suitably has good compatibility with an aqueous solvent. Specifically, examples of the organic solvents include monovalent lower alcohols with the number of carbon atoms of 1 to 6: namely, methanol, ethanol, propyl alcohol, isopropyl alcohol, butanol, pentanol, and hexanol. The carbon atoms forming each of these monovalent lower alcohols may form a linear skeleton, a branch skeleton, a cyclic skeleton, or a combination of two or more of these skeletons. Each monovalent lower alcohol may be diluted with water, as appropriate, before being used. Among these alcohols, a monovalent lower alcohol with the number of carbon atoms of 1 to 4, namely, methanol, ethanol, propyl alcohol, isopropyl alcohol, or butanol is beneficially used as the organic solvent for pTS.
[0063] The oxidant component contained in the pTS solution is not limited to any particular substance as long as the oxidant component is capable of activating the polymerization reaction through which pTS and EDOT in contact with each other are polymerized into PEDOT-pTS. Examples of the oxidant component include ions of transition elements and halogens.
[0064] Examples of the transition elements include: elements of the first transition series such as iron, titanium, chromium, manganese, cobalt, nickel, and zinc; elements of the second transition series such as molybdenum, silver, zirconium, and cadmium; and elements of the third transition series such as cerium, platinum, and gold. Among these elements, the elements of the first transition series such as iron and zinc are used suitably.
[0065] The oxidant component content of the pTS solution varies depending on the type of the oxidant component to be used, and is not limited to any particular content as long as the above-described polymerization reaction is activated with the oxidant component content. For example, in the case of ferric ions (Fe 3+ ) used in an example described herein, they are blended, in the form of ferric chloride, suitably at a ratio of 1-10% by mass, and more suitably at a ratio of 3-7% by mass with respect to the pTS solution. An excessive amount of ferric chloride blended in the solution would accelerate the polymerization reaction, but would make it difficult to remove iron in a later process step. An insufficient amount of ferric chloride would delay the polymerization reaction.
[0066] The content of pTS functioning as a dopant in the pTS solution is suitably 0.1-10% by mass, and more suitably 0.15-7% by mass, even more suitably 1-6% by mass, and most suitably 2-5% by mass with respect to the solution.
[0067] Next, (2) after EDOT monomers are added to the solution, the solution is heated suitably at 50-100° C. for 10-60 minutes, more suitably at 50-80° C. for 10-40 minutes, and even more suitably at 60-80° C. for 10-30 minutes. After this heating, the base is taken out of the solution, and washed beneficially with water, more beneficially with distilled water or deionized water. Thereafter, the base is dried in a thermostatic oven, with hot air or warm air, in the sun, or in other manners. At room temperature, EDOT is in a liquid state and soluble in water, and may be diluted in an aqueous solvent such as water, as appropriate, before being used.
[0068] The ratio between the amounts of pTS solution and EDOT (pTS solution:EDOT) in terms of volume ratio ranges from 10:1 to 100:1, and suitably from 20:1 to 40:1.
[0069] Either or both of the pTS solution and EDOT that are used in the first and second embodiments of the present invention may contain, as necessary, any other additional components blended therein, provided that such components do not reduce the advantages of the present invention either quantitatively or qualitatively: specifically, provided that such components do not reduce the degree of uniformity of the pTS-EDOT mixture solution applied to the base, or deteriorate the conductivity of the resultant electrically conductive material.
[0070] Examples of those additional components include glycerin, polyethylene glycol-polyprene glycol polymer, ethylene glycol, sorbitol, sphingosine, and phosphatidyl choline. Among other things, glycerol, polyethylene glycol-polyprene glycol polymer, and sorbitol are used particularly suitably. Blending these additional components adjusts the wettability property of the electrically conductive material and provides flexibility to the electrically conductive material, which may enhance the affinity for living body tissues, in particular, for skin when the electrically conductive material is used as a bioelectrode. Other examples of the additional components include surfactants, binders, natural polysaccharide, thickeners such as carboxymethylcellulose (CMC), and emulsion stabilizers.
[0071] FIG. 1 shows the formation reaction of PEDOT-pTS in the method for producing the electrically conductive material according to the first and second embodiments of the present invention. Note that a silk fabric or a silk thread is used as the base, but the base is not limited to this. Further, as mentioned above, Fe 3+ is used as an exemplary oxidant component, and the oxidant component of the present invention is not limited to this.
[0072] As can be seen from the foregoing, the electrically conductive material of the present invention is suitably produced by the production method of the present invention. The method for producing the electrically conductive material according to embodiments of the present invention includes a heating process step to accelerate the formation reaction of PEDOT-pTS, and consequently, may facilitate the polymerization of PEDOT-pTS with the base. Further, a desired area of the base is immersed in the solution in the process step of immersing the base into the organic solvent-based solution, or the solution is applied, by printing for example, to a desired area of the base in the process step of printing. In this manner, a conductive area may be formed in a desired shape. As a result, the electrically conductive material may be produced which has a conductive area having a shape suitable for its applications and intended operating environment.
[0073] The method for producing the electrically conductive material according to each embodiment of the present invention is capable of applying the conductive polymers, i.e., PEDOT-pTS, to the surface of the base more uniformly and evenly than the electrolytic polymerization method or any other method of the known art, thus reducing the electrical resistance value. Further, this method also makes it much simpler, and much less troublesome, to produce the electrically conductive material than the electrolytic polymerization method or any other method of the known art. Such simplicity, which constitutes one of advantageous features of the method (i.e., the chemical polymerization method) for producing the electrically conductive material according to the embodiments of the present invention, allows a fiber to be turned into an electrically conductive one through a process such as printing or spraying which has been impractical according to the electrolytic polymerization method.
[0074] The electrically conductive material according to each embodiment of the present invention is pleasant to the touch, highly durable and highly water-resistant, and also has flexibility, a low electrical resistance value, and high biocompatibility. Therefore, the electrically conductive material may be used, for example, for a wearable electrode for healthcare, an electrode for measuring a potential within a muscle or on a skin surface, an electrode for measuring an electrocardiogram, an electrode for measuring an electroencephalography, and a bioelectrode for use in clinical therapy.
[0075] The electrically conductive material according to each of the embodiments of the present invention was tested on electrical resistance value, biocompatibility, and other properties. The test results as well as evaluation and studies made on the test results are set forth below.
[0076] [Study on Base]
[0077] Several bases including silk threads degummed in different ways were tested to determine whether the difference in the degumming way caused to the resultant electrically conductive materials to have different resistance values. Each of the silk threads under test included eight silk fibers having a size of 21 denier and had a size of 168 denier (with a cross-sectional area of about 2.5×10 −4 cm 2 ). The silk threads under test were of the five types of: raw silk thread (hereinafter referred to as non-degummed), a phosphoric acid-degummed thread (acid degummed), a soaping agent-degummed thread (soaping agent degummed), a soap degummed thread (alkaline degummed), and an enzyme-degummed thread (degummed using protease).
[0078] Each of the five types of the silk threads was formed into an electrically conductive material by the production method according to the embodiment of the present invention described below. Specifically, 6.3 ml of butanol solution (product of Heraeus K.K.; product name “CLEVIOS® C-B 40 V2”; containing about 4% by mass of p-toluene sulfonic acid iron (III)) was prepared such that the butanol solution contained pTS and ions of ferric (III) that is a transition metal. Each silk thread was immersed in the prepared solution. Next, 220 μl of EDOT (product of Heraeus K.K., product name “CLEVIOS® MV2”; containing about 98.5% by mass of EDOT) was added to the solution. Thereafter, the solution was heated at 50-100° C. for 10-60 minutes in a thermostatic oven. After the heating, each thread was taken out of the solution. Each thread was then washed three times with deionized water, and subsequently, dried in a thermostatic oven at 70° C. Among the electrically conductive materials produced under these conditions, ones prepared by being heated at 70° C. for 20 minutes were subjected to the following tests focusing on the differences in degumming way.
[0079] Each of the electrically conductive materials formed of the above silk threads was subjected to resistance value measurement. FIG. 2 shows the results of the measurement. As shown in FIG. 2 , it was confirmed that the electrically conductive material formed of the enzyme-degummed thread had the lowest resistance value, and the electrically conductive material formed of the phosphoric acid-degummed thread also had a low resistance value. Here, the electrical resistance value refers to the electrical resistance value per centimeter of each of those threads, measured using a tester (the same applies to the following).
[0080] FIGS. 3A-3E are electron micrographs of the surfaces of the silk threads degummed in different ways. As shown in FIGS. 3A-3E , the surface of the enzyme-degummed thread is the smoothest, and the surface of the phosphoric acid-degummed thread is also relatively smooth. This suggests that the good surface condition of the enzyme-degummed thread and the phosphoric acid-degummed thread is a factor in the low resistance value of the electrically conductive material. That is to say, forming an electrically conductive material using a base having a smooth surface such as the enzyme-degummed thread or the phosphoric acid-degummed thread would allow PEDOT-pTS to be applied densely to the surface of the base and reduce the resistance value.
[0081] [Production Method]
[0082] Note that the following is merely an example, and the present invention is not intended to be limited to this.
[0083] The electrically conductive material produced by the method for producing electrically conductive material disclosed in [Study on Base] above (hereinafter referred to as “chemical polymerization method”) was compared with an electrically conductive material produced by the electrolytic polymerization method as disclosed in Patent Document 1 and Non-Patent Document 1. Both of these electrically conductive materials included, as the base, the raw silk thread used in [Study on Base].
[0084] One of these two types of electrically conductive materials was produced by the electrolytic polymerization method as described in Patent Document 1 and Non-Patent Document 1. Specifically, the raw silk thread was kept immersed for one night in a mixture solution obtained by adding EDOT at a mass ratio of 0.1% to a PEDOT-PSS solution. Next, an Ag/AgCl electrode as a reference electrode and a Pt electrode as a counter electrode were immersed in the mixture solution, and both ends of the raw silk thread were pinched by a clip connected to a working electrode, while a middle portion of the raw silk thread kept immersed in the mixture solution. A potential for polymerization (of 0.8V vs. Ag/AgCl) was applied to both ends of the raw silk thread using a potentiostat to perform the electrolytic polymerization until the total potential reached 76.8 μC. Thereafter, the raw silk thread was lifted out of the mixture solution, and then dried in a thermostatic oven at 70° C.
[0085] The other type of electrically conductive material was produced by the chemical polymerization method using the raw silk thread heated at 70° C. for 20 minutes, i.e., under one of the heating conditions described for [Study on Base] above.
[0086] The resistance values of the two types of electrically conductive materials produced by the chemical polymerization method and the electrolytic polymerization method, respectively, were measured, and the results are shown in FIG. 4 . As shown in FIG. 4 , it was confirmed that the resistance value of the electrically conductive material produced by the chemical polymerization method is lower by about four orders of magnitude than that of the electrically conductive material produced by the electrolytic polymerization method. As can be seen, the electrically conductive material produced by the chemical polymerization method, having a high degree of conductivity and a lower resistance value, enables noise reduction and more accurate measurement when used as an electrode.
[0087] FIGS. 5A and 5B are electron micrographs of the electrically conductive material produced by the electrolytic polymerization method and the electrically conductive material produced by the chemical polymerization method, respectively. As shown in FIG. 5A , it was confirmed that the electrically conductive material produced by the electrolytic polymerization method has PEDOT-PSS applied locally to parts of the surface of the base. In contrast, as shown in FIG. 5B , it was confirmed that the electrically conductive material produced by the chemical polymerization method has PEDOT-pTS applied uniformly and evenly over the entire surface of the base. It is a general understanding that conductivity increases and the resistance value decreases with increase in the surface area of PEDOT covering the surface of a base. Thus, the difference in the degree of uniformity of the applied PEDOT shown in FIGS. 5A and 5B seems to have caused the difference in resistance value.
[0088] [Study on Biocompatibility]
[0089] The electrically conductive material according to the embodiment of the present invention was tested on biocompatibility. First, the surface of a cover glass was spin-coated with PEDOT-pTS dripped on the surface, thereby forming a thin film of PEDOT-pTS thereon.
[0090] Primary culture of brain cells of a chick embryo was conducted on the thin film. In this culture, the brain of the chick embryo was soaked in a trypsin solution for about 10 minutes, and then, the solution was agitated about 10 times using a pipette. Thereafter, 300 μl of the solution was transferred to a 35 mm culture plate, and 2 ml of a culture solution comprised of Neurobasal medium, including 2% B27 supplement, 0.074 mg/ml of L-glutamine, 25 μM of glutamate, and 20 ng/ml of NGF, was added to the culture plate. The culture plate was then placed in an incubator at 37° C. and cultured for 24 hours. After the completion of the culture, the cells were stained with 5 μg/ml of Acridine Orange, a fluorescent dye. The cells were then excited with Ar laser to determine viability. A dead cell does not eject the fluorescent dye from itself, and fluorescence is observed. For comparison, cells were cultured using a cover glass not spin-coated with PEDOT-pTS, and observed for fluorescence.
[0091] FIGS. 6A-6D show the results. FIGS. 6A and 6B are micrographs showing the brain cells of the chick embryo cultured on the cover glass, and observed under ordinary light and fluorescence, respectively. FIGS. 6C and 6D are micrographs showing the brain cells of the chick embryo cultured on the cover glass coated with the PEDOT-pTS for use in the method for producing the electrically conductive material according to the embodiment of the present invention, and observed under ordinary light and fluorescence, respectively. As shown in FIG. 6B , it was confirmed that on the cover glass not spin-coated with PEDOT-pTS, many cells emitted fluorescence, i.e., many cells were dead. In contrast, as shown in FIG. 6D , it was confirmed that on the cover glass spin-coated with PEDOT-pTS, almost no fluorescence was observed, which means that the cultured cells were alive. These results demonstrate that PEDOT-pTS has high biocompatibility and causes almost no rejection in living body's tissues.
[0092] Next, as shown in FIG. 7A , a potential was measured within a muscle of a chick embryo. Specifically, in the potential measurement, the electrically conductive material according to the embodiment of the present invention, which included a raw silk thread as the base and PEDOT-pTS applied to the surface of the base, was used as an element of a bioelectrode. The electrically conductive material was produced using the raw silk thread heated at 70° C. for 20 minutes, i.e., under one of the heating conditions described for [Study on Base] above. The measurement results are shown in FIG. 7B . As shown in FIG. 7B , it was confirmed that the electrically conductive material was capable of measuring a potential variation which occurred when the muscle was moved by stimulation.
[0093] [Study (1) on Multipoint Surface Electrode]
[0094] Study on this surface myoelectric potential measurement is shown in the schematic diagrams and the potential measurement chart of FIG. 8 .
[0095] A ribbon-shaped silk fabric having a width of 1 cm and a length of 10 cm (a plain-woven silk fabric made of silk threads degummed with an enzyme (i.e., a protease)) was used as the base, and heated at 70° C. for 20 minutes, i.e., under one of the heating conditions of the production method (the chemical polymerization method) disclosed in [Study on Base], thereby producing an electrically conductive material. The electrically conductive material thus produced was cut into square pieces measuring 1 cm on each side (and having an area of 1 cm 2 ). In this manner, ten surface electrode elements having this size were produced. The electrical resistance value between both ends of each of these ten flat plate-shaped pieces of the electrically conductive material was measured with a tester. All of the pieces had a resistance value of less than 1.6 kΩ. A linear electrode element made of a raw silk thread (non-degummed) also heated at 70° C. for 20 minutes as described in [Study on Base] was sewn on and connected to each of the surface electrode elements, thereby producing unit elements for a multipoint surface electrode. By using a needle, the linear portion of each unit element was made to perpendicularly penetrate a silk fabric (a plain-woven silk fabric made of silk threads degummed with an enzyme (i.e., a protease)) for use as an insulator, and then sewn on the silk fabric in a simple manner. The silk fabric had a square shape measuring 10 cm on each side (and having an area of 100 cm 2 ). The nine unit elements were sewn on a surface of the silk fabric at regular intervals of 0.5 cm. In this manner, the multipoint surface electrode (see portion (a) of FIG. 8 ) was produced.
[0096] Next, the multipoint surface electrode was fixed on an arm of a subject such that the surface on which the surface electrode elements were exposed was in contact with the subject's arm. Potential variations caused by the motion of the subject's hand were measured with a commercially available wireless electromyography (ID3PAD: product of Oisaka Electronic Equipment Ltd.) (see portion (b) of FIG. 8 ). In this measurement, the multipoint surface electrode was brought into direct contact with the skin, without any substance for reducing impedance, such as gel, applied between the multipoint surface electrode and the skin.
[0097] [Study (2) on Multipoint Surface Electrode]
[0098] Study on this surface brain wave measurement is shown in the schematic diagrams and the potential measurement chart of FIG. 9 .
[0099] Silk threads having a diameter of 0.2 mm (and degummed with an enzyme (i.e., a protease)) were heated at 70° C. for 20 minutes, i.e., under one of the heating conditions of the production method (the chemical polymerization method) disclosed for [Study on Base], thereby producing linear electrode elements each including the silk thread as the base. A silk fabric (a plain-woven silk fabric made of silk threads degummed with an enzyme (i.e., a protease)) having a square shape measuring 20 mm on each side (and having an area of 400 mm 2 ) was provided for use as an insulator. One linear electrode element was made to perpendicularly penetrate the silk fabric from the back of the silk fabric. The tip end of the linear electrode element that had penetrated the silk fabric was then again made to penetrate the silk fabric from the front such that a portion of the linear electrode element with a length of 1 mm was exposed on the front. In this manner, the linear electrode was sewn and fixed as a first liner electrode element. Subsequently, another portion of the linear electrode element was also sewn and fixed in the proximity of the sewn and fixed portion of the first linear electrode element such that another portion intersected at right angles with the 1 mm exposed portion of the first linear electrode element. These two portions of the linear electrode element intersecting with each other at right angles formed a set of unit elements for a multipoint surface electrode. Each set of unit elements, which included two 1 mm portions of the silk thread having a diameter of 0.2 mm, had an electrode area of 0.004 cm 2 . Nine sets of unit elements were sewn at nine points arranged at regular intervals of 5 mm on the square fabric surface measuring 20 mm on each side. In this manner, a multipoint surface electrode for brain wave measurement was produced (see portion (a) of FIG. 9 ).
[0100] Next, the electrode surface of the multipoint surface electrode for brain wave measurement was brought into contact with the surface of the brain of a chick embryo (19 day old) from which the cranial bones had been removed. A commercially available RZ5 bio amp processor (product of Tucker-Davis Technologies, Inc.) was wired to the multipoint surface electrode to measure cranial nerve activity (see portion (b) of FIG. 9 ). In the measurement, the multipoint surface electrode was brought into direct contact with the brain, without any substance for reducing impedance, such as gel, applied between the multipoint surface electrode and the skin.
[0101] As described above, the electrically conductive material according to the embodiment of the present invention has high biocompatibility, and is sufficiently useful as a bioelectrode. In particular, if the base includes silk fibers, the electrically conductive material may be used suitably as a bioelectrode. | An electrically conductive material including a base and a conductive polymer applied uniformly to the base's surface and having a reduced resistance value. Specifically, the electrically conductive material includes PEDOT-pTS, serving as a conductive polymer, applied to the base comprised mostly of silk. Also the enclosed provide a method for producing the electrically conductive material, and a bioelectrode including it. The method includes the steps of: (1) applying a p-toluenesulfonate (pTS) solution containing an oxidant component and pTS to a base selected from the group consisting of a silk fiber, a fiber containing sericin or fibroin, and a fiber coated or soaked with sericin or fibroin; and (2) further applying 3,4-ethylenedioxythiophene (EDOT) to the base that already has the oxidant component and pTS applied thereto through the step (1), thereby triggering, at the base, a polymerization reaction to form poly(3,4-ethylene-dioxythiophene)-p-toluenesulfonate (PEDOT-pTS) and applying the formed PEDOT-pTS to the base. | 3 |
CROSS REFERENCE AND INCORPORATION BY REFERENCE
[0001] This patent disclosure relates to provisional patent application filed on even date hereof; namely, application Ser. No. 60/745,789 (Atty Dkt. P-24201.00) entitled, “FAULT TOLERANT SENSORS AND METHODS FOR IMPLEMENTING FAULT TOLERANCE IN IMPLANTABLE MEDICAL DEVICES,” the entire contents, including exhibits appended thereto, are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to fault tolerant sensors and related components that couple to an active implantable medical device (AIMD).
BACKGROUND OF THE INVENTION
[0003] Implantable medical devices are used to monitor, diagnose, and/or deliver therapies to patients suffering from a variety of conditions. Exemplary AIMDs include implantable pulse generators (IPGs) including pacemakers, gastric, nerve, brain and muscle stimulators, implantable drug pumps, implantable cardioverter-defibrillators (ICDs) and the like.
[0004] Due in part to the fact that an AIMD resides in a difficult environment and can be exposed to vibratory, tensile stresses, forces and caustic materials, there exists a need for a modicum of fault tolerance against a variety of possible device, component and system failures and improper operation. Among other things, certain forms, aspects and embodiments of the present invention provide improved and more predictable performance of an AIMD when subjected to a variety of failure modes.
BACKGROUND
[0005] There are many situations in which a patient requires long-term monitoring and when it may be desirable to implant a sensor for monitoring within the body of the patient. One such monitor is a pressure monitor, which can measure the pressure at a site in the body, such as a blood vessel or a chamber of the heart. When implanted in a vessel or a heart chamber, the sensor responds to changes in blood pressure at that site. Blood pressure is measured most conveniently in units of millimeters of mercury (mm Hg) (1 mm Hg=133 Pa).
[0006] The implanted pressure sensor is coupled to an implanted medical device, which receives analog signals from the sensor and processes the signals. Signals from the implanted pressure sensor may be affected by the ambient pressure surrounding the patient. If the patient is riding in an airplane or riding in an elevator in a tall building, for example, the ambient pressure around the patient may change. Changes in the ambient pressure affect the implanted pressure sensor, and may therefore affect the signals from the pressure sensor.
[0007] A typical implanted device that employs a pressure sensor is not concerned with total pressure, i.e., blood pressure plus ambient pressure. Rather, the device typically is designed to monitor blood pressure at the site of the internal sensor. To provide some compensation for changes in ambient pressure, some medical devices take additional pressure measurements with an external pressure sensor. The external pressure sensor, which may be mounted outside the patient's body, responds to changes in ambient pressure, but not to changes in blood pressure. The blood pressure is a function of the difference between the signals from the internal and external pressure sensors.
[0008] Although the internal pressure sensor may generate analog pressure signals as a function of the pressure at the monitoring site, the pressure signals are typically converted to digital signals, i.e., a set of discrete binary values, for digital processing. An analog-to-digital (A/D) converter receives an analog signal, samples the analog signal, and converts each sample to a discrete binary value. In other words, the pressure sensor generates a pressure signal as a function of the pressure at the monitoring site, and the A/D converter maps the pressure signal to a binary value.
[0009] The A/D converter can generate a finite number of binary values. An 8-bit A/D converter, for example, can generate 256 discrete binary values. The maximum binary value corresponds to a maximum pressure signal, which in turn corresponds to a maximum pressure at the monitoring site. Similarly, the minimum binary value corresponds to a minimum pressure signal, which in turn corresponds to a minimum site pressure. Accordingly, there is a range of pressure signals, and therefore a range of site pressures, that can be accurately mapped to the binary values.
[0010] In a patient, the actual site pressures are not constrained to remain between the maximum and minimum monitoring site pressures. Due to ambient pressure changes or physiological factors, the pressure sensor may experience a site pressure that is “out of range,” i.e., greater than the maximum monitoring site pressure or less than the minimum monitoring site pressure. In response to an out-of-range pressure, the pressure sensor generates an analog signal that is greater than the maximum pressure signal or less than the minimum pressure signal. An out-of-range pressure cannot be mapped accurately to a binary value.
[0011] For example, the pressure sensor may experience a high pressure at the monitoring site that exceeds the maximum site pressure. In response, the pressure signal generates a pressure signal that exceeds the maximum pressure signal. The pressure signal is sampled and the data samples are supplied to the A/D converter. When the A/D converter receives a data sample that is greater than the maximum pressure signal, the A/D converter maps the data sample to a binary value that reflects the maximum pressure signal, rather than the true value of the data sample. In other words, the data sample is “clipped” to the maximum binary value. Similarly, when the A/D converter receives a data sample that is below the minimum pressure signal, the converter generates a binary value that reflects the minimum pressure signal rather than the true value of the data sample.
[0012] Because of changes in ambient pressure, pressures sensed by the internal pressure sensor may be in range at one time and move out of range at another time. When the pressures move out of range, some data associated with the measured pressures may be clipped, and some data reflecting the true site pressures may be lost. In such a case, the binary values may not accurately reflect the true blood pressures at the monitoring site.
[0013] To avoid clipping, the implanted device may be programmed to accommodate an expected range of site pressures. Estimating the expected range of site pressures is difficult, however, because ambient pressure may depend upon factors such as the weather, the patient's altitude and the patient's travel habits. Pressures may be in range when the patient is in one environment, and out of range when the patient is in another environment.
[0014] The risk of clipping can further be reduced by programming the implanted device with a high maximum site pressure that corresponds to the maximum binary value and with a low minimum site pressure that corresponds to the minimum binary value. Programming the device for a high maximum and a low minimum creates a safety margin. The price of safety margins, however, is a loss of sensitivity. Safety margins mean that pressures near the maximum and minimum site pressures are less likely to be encountered. As a result, many of the largest and smallest binary values are less likely to be used, and the digital data is a less precise representation of the site pressures.
BRIEF SUMMARY OF THE INVENTION
[0015] The present invention provides one or more structures, techniques, components and/or methods for avoiding or positively resolving one or more possible failure modes for a chronically implanted medical device that couples to one or more sensors.
[0016] In one embodiment of the invention, a possible fault scenario involving a breach of a portion of a layer of insulation on an elongated medical electrical lead which couples signals and/or electrical energy between a sensor and a circuit-bearing, active AIMD disposed within a substantially hermetic housing. According to this scenario, an initial response to a fault involves disconnecting or removing the power source from the sensor. Subsequently, the power source is periodically, aperiodically or otherwise reconnected in order to determine if the original fault persists. If not, then the power to the sensor can be restored and physiologic signals transmitted to operative circuitry of the AIMD.
[0017] According to another aspect of the invention, however, an intermediate sensor operating mode is enabled; for example, the power source for the sensor is only coupled thereto temporarily. In an exemplary embodiment, the power source is limited to intervals of time when stimulation and/or capture of excitable tissue (e.g., myocardial tissue, nerve fibers, muscular tissue, etc.) is not likely to occur. One manner of achieving involves applying energy to a sensor(s) during the absolute and/or relative refractory period of the myocardium to thereby minimize any undesired tissue activation. One advantage of this selective coupling and uncoupling of sensor energy is that substantially beat-to-beat physiologic parameters can continue to be collected without interrupting therapy delivery. Thus, one aspect of this form of the invention involves the ability to maintain AIMD (and sensor) functionality and avoid the possibility of having to explant the AIMD and/or sensor from the patient.
[0018] In one embodiment the AIMD provides only physiological sensing of a patient parameter, such as endocardial pressure. In one form of this embodiment, the sensor comprises an absolute pressure sensor adapted for chronic implantation within a portion of a right ventricle (RV) of a patient. The portion could include the RV outflow tract (RVOT) which is a region of relatively high-rate blood flow which correspondingly requires a robust sensor capsule and coupling to a medical electrical lead coupled thereto. Thus in lieu of providing therapy at some time when the relevant tissue remains excitable, the sensor power-switching regimen operates to ensure that no current or voltage shunting occurs to the tissue when it is non-refractory.
[0019] In another embodiment, an AIMD is configured to sense a physiologic parameter of a patient (e.g., blood pressures, acceleration, pH levels, lactate, saturated oxygen, blood sugar, calcium, potassium, sodium, etc.) and provide a therapy such as cardiac pacing, high-energy cardioversion/defibrillation therapy and/or a drug or substance delivery regimen or the like. For example, in an AIMD configured to chronically measure blood pressure, provide cardiac pacing therapy and, as appropriate, deliver high-energy defibrillation therapy, an outer insulation breach of a medical electrical lead could cause a malfunction requiring explant of the AIMD. According to the invention, a refinement of the fault mitigation for this particular embodiment involves coupling the energy to the sensor during the refractory period and, in addition, decoupling the power from the sensor during or in anticipation of high energy therapy delivery (e.g., cardioversion and/or defibrillation)
[0020] In yet another embodiment of the invention, an AIMD configured with three or more discrete medical electrical leads that each independently couple to relatively low power AIMD circuitry disposed within the AIMD housing can be rendered highly robust vis-à-vis a voltage- or current-shunt or path to the body or body fluids. In this form of the invention, the ventricular-based sensor(s) should only be coupled to a power source during a refractory period of both ventricles. Accordingly, in the event that an atrial-based sensor is utilized the power source should only be coupled to the sensor during the atrial refractory period (absolute and/or relative refractory period).
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a diagram of a human body with an implanted medical device and pressure sensors.
[0022] FIG. 2 is a simplified block diagram illustrating an exemplary system that implements the an embodiment of the invention wherein a physiologic sensor provides chronic monitoring and diagnostic for a patient.
[0023] FIG. 3 is an illustration of an exemplary implantable medical device (AIMD) connected to monitor a patient's heart.
[0024] FIG. 4 is a block diagram summarizing the data acquisition and processing functions appropriate for practicing the invention.
[0025] FIGS. 5A and 5B are elevational side views depicting a pair of exemplary medical electrical leads wherein in FIG. 5A a pair of defibrillation coils are disposed with a sensor capsule intermediate the coils and in FIG. 5B the sensor capsule is disposed distal the coils.
[0026] FIG. 6 is a cross sectional view of a coaxial conductor adapted for use with an implantable sensor.
[0027] FIG. 7 is a schematic illustration of a sensor capsule coupled to a housing of an IMD and a source of reference potential.
[0028] FIG. 8 . is a schematic view of a sensor capsule coupled to a electrical current detector and operative circuitry housed within an IMD.
[0029] FIG. 9 is a schematic view of an IMD having a proximal lead-end set screw for mechanically retaining the proximal end of a medical electrical lead within a connector block, wherein said set screw couples to a source of reference potential.
DETAILED DESCRIPTION
[0030] FIG. 1 is a diagram of a body of a patient 10 having an AIMD 12 according to one embodiment of the present invention. As depicted in FIG. 1 lead 14 operatively couples to circuitry (not shown) within the AIMD 12 and extends into the right ventricle 16 of the heart 18 . A chronically implantable pressure sensor 20 is shown disposed within a portion of a right ventricle (RV) 16 and couples to lead 14 . The pressure sensor 20 monitors and measures changes in blood pressure in the RV 16 . The blood pressure in RV 16 is a function of factors such as the volume of RV 16 , the pressure exerted by the contraction of heart 18 and the ambient pressure around patient 10 and the blood pressure varies throughout the cardiac cycle as is well known in the art. While a pressure sensor 20 is depicted in FIG. 1 diverse other sensors can directly benefit from the teaching of the present invention as noted hereinabove.
[0031] In one form of the invention the AIMD 12 receives analog signals from the implanted pressure sensor 20 via lead 14 although digital sensors and/or circuitry can be utilized in conjunction with the invention. As noted, in the depicted embodiment the signals are a function of the pressure sensed by implanted pressure sensor 20 at the monitoring site (e.g. RV 16 ) which can of course include myriad different locations on or about the heart and other muscles, circulatory system, nervous system, digestive system, skeleton, brain, diverse organs, and the like. In the depicted embodiment, patient 10 carries or otherwise provides or maintains access to an external pressure sensor or reference 22 which is used to correct the readings of the implanted absolute-type pressure sensor 20 . FIG. 1 depicts external pressure sensor 22 coupled to a belt or strap 24 coupled to the arm of patient 10 , but this is but one of many possible sites for external pressure sensor 22 . The external pressure sensor 22 responds to changes in ambient pressure, and is unaffected by blood pressure in the RV 16 . The AIMD 12 receives signals from external pressure sensor 22 via communication such as radio frequency (RF) telemetry. Alternatively, the AIMD 12 need not communicate with external pressure sensor 22 in any way.
[0032] The AIMD 12 optionally includes a digital processor. Thus, the analog signals from implanted pressure sensor 20 are converted to digital signals for processing. Referring briefly to FIG. 2 , the analog signals are first amplified by an amplifier 32 and are sampled and are mapped to discrete binary values by an A/D converter 34 . Each binary value corresponds to a pressure signal that in turn corresponds to a site pressure. The A/D converter 34 maps each sample to a binary value that corresponds most closely to the actual pressure signal and site pressure reflected by the sample.
[0033] The sensitivity of AIMD 12 to changes in pressure is a function of the range of pressures that map to a single binary value. The smaller the pressure change represented by consecutive binary values, the more sensitive implanted medical device 12 is to changes in pressure. For example, an 8-bit A/D converter may be configured to map pressures between a minimum site pressure of 760 mm Hg and a maximum site pressure of 860 mm Hg to discrete binary values. In this example, a one-bit increase represents a pressure increase of about 0.4 mm Hg.
[0034] In a conventional implanted medical device, there may be a tradeoff between range and sensitivity. When the number of possible discrete binary values is fixed, expanding the range of site pressures that are represented by the binary values results in a decrease in sensitivity, because a one-bit change represents a larger pressure change. Similarly, decreasing the range results in an increase in sensitivity because a one-bit change represents a smaller pressure change.
[0035] In an illustrative example, an 8-bit A/D converter may be configured to map pressures between 760 mm Hg and 860 mm Hg to discrete binary values, with a one-bit increase representing a pressure increase of about 0.4 mm Hg. When the same 8-bit A/D converter is configured to map pressures between 746 mm Hg and 874 mm Hg to discrete binary values, the overall range of site pressures that can be mapped to binary values expands by 128 mm Hg. The sensitivity, however, decreases. A one-bit increase represents a pressure increase of 0.5 mm Hg.
[0036] Not all changes to range affect sensitivity. In some circumstances, a range may be offset without affecting sensitivity. In an offset, the minimum site pressure and the maximum site pressure are increased or decreased by the same amount. For example, a 8-bit A/D converter may be configured to map pressures between 760 mm Hg and 860 mm Hg to discrete binary values, with a one-bit increase representing a pressure increase of about 0.4 mm Hg. When the pressure range is shifted downward to pressures between 740 mm Hg and 840 mm Hg, the range is offset but not expanded. When the range is offset, sensitivity is not affected. A one-bit increase still represents a pressure increase of about 0.4 mm Hg.
[0037] Implanted medical device 12 implements techniques for automatically adjusting mapping parameters in response to changes in pressure conditions. In particular, implanted medical device 12 periodically evaluates the digital pressure data to determine whether pressure data may be going out of range, and expands and/or offsets the range to avoid having data go out of range. In addition, implanted medical device 12 determines whether the range can be decreased so that sensitivity can be enhanced.
[0038] FIG. 2 is a block diagram of an exemplary system 30 that implements the invention. Pressure sensor 20 supplies an analog pressure signal to amplifier 32 . The analog pressure signal is a function of the site pressure, where pressure sensor 20 is disposed. The analog pressure signal may be, for example, a voltage signal. Amplifier 32 amplifies the signal by, for example, amplifying the voltage. Amplifier 32 may perform other operations such as serving as an anti-aliasing filter. Amplifier 32 has an adjustable gain and an adjustable offset. The gain and offset of amplifier 32 are adjustable under the control 42 of a controller, which may take the form of a microprocessor 36 . The controller may take other forms, such as an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or any other circuit including discrete and/or integrated components and that has control capabilities.
[0039] Amplifier 32 supplies the amplified analog signal to A/D converter 34 . The range and resolution of pressure signals supplied to A/D converter 34 is a function of the gain of amplifier 32 and the offset of amplifier 32 . By adjusting the gain and/or offset of amplifier 32 , microprocessor 36 regulates the mapping parameters; that is, the correspondence between site pressures and binary values. A/D converter 34 samples the pressure signals from amplifier 32 and converts the samples into discrete binary values, which are supplied to microprocessor 36 . In this way, microprocessor 36 , amplifier 32 and A/D converter 34 cooperate to map the site pressures to binary values.
[0040] The number of possible discrete binary values that can be generated by A/D converter 34 is fixed. When there is a risk of data out of range, it is not feasible to increase the number of binary values that represent the site pressures. As will be described in more detail below, microprocessor 36 adjusts the gain and/or the offset of amplifier 32 so that the data remain in range and so that the digital pressure data generated by A/D converter 34 accurately reflect the site pressures sensed with pressure sensor 20 .
[0041] Microprocessor 36 processes the digital pressure data according to algorithms embodied as instructions stored in memory units such as read-only memory (ROM) 38 or random access memory (RAM) 40 . Microprocessor 36 may, for example, control a therapy delivery system (not shown in FIG. 2 ) as a function of the digital pressure data.
[0042] Microprocessor 36 may further compile statistical information pertaining to the digital pressure data. In one embodiment, microprocessor 36 generates a histogram of the digital pressure data. The histogram, which may be stored in RAM 40 , reflects the distribution of pressures sensed by pressure sensor 20 .
[0043] The histogram includes a plurality of “bins,” i.e., a plurality of numbers of digital data samples of comparable magnitude. For example, a histogram that stores the number of digital values corresponding to pressures between 760 mm Hg and 860 mm Hg may include twenty bins, with each bin recording the number of data samples that fall in a 5 mm Hg span. The first bin holds the number of values between 760 mm Hg and 765 mm Hg, while the second bin holds the number of values between 765 mm Hg and 770 mm Hg, and so on. More or fewer bins may be used.
[0044] The distribution of values in the bins provides useful information about the pressures in right ventricle 16 . Data accumulates in the histogram over a period of time called a “storage interval,” which may last a few seconds, a few hours or a few days. At the end of the storage interval, microprocessor 36 stores in RAM 40 information about the distribution of pressures, such as the mean, the standard deviation, or pressure values at selected percentiles. Microprocessor 36 may then clear data from the histogram and begin generating a new histogram.
[0045] When microprocessor 36 adjusts the mapping parameters, the new histogram may be different from the preceding histogram. In particular, the new histogram may record the distribution of an expanded range of pressure data, or a reduced range of pressure data, or a range that has been offset up or down. In general, the adjustments to the mapping parameters tend to center the distribution in the histogram, and tends to reduce the number of values in the highest and lowest bins. Microprocessor 36 adjusts the mapping parameters based upon the distribution of digital pressure data in the preceding histogram. Microprocessor 36 may make the adjustments to avoid data out of range, to avoid having unused range, or both.
[0046] In one embodiment of the invention, microprocessor 36 senses the possibility of out-of-range data or unused range by sensing the contents of the boundary bins of the histogram, for example by checking whether the data distribution has assigned values to the bins that accumulate the lowest values and the highest values of the histogram. As a result of checking the bins, microprocessor 36 may automatically adjust the gain, or the offset, or both of amplifier 32 .
[0047] FIG. 3 is an illustration of an exemplary AIMD 100 configured to deliver bi-ventricular, triple chamber cardiac resynchronization therapy (CRT) wherein AIMD 100 fluidly couples to monitor cardiac electrogram (EGM) signals and blood pressure developed within a patient's heart 120 . The AIMD 100 may be configured to integrate both monitoring and therapy features, as will be described below. AIMD 100 collects and processes data about heart 120 from one or more sensors including a pressure sensor and an electrode pair for sensing EGM signals. AIMD 100 may further provide therapy or other response to the patient as appropriate, and as described more fully below. As shown in FIG. 3 , AIMD 100 may be generally flat and thin to permit subcutaneous implantation within a human body, e.g., within upper thoracic regions or the lower abdominal region. AIMD 100 is provided with a hermetically-sealed housing that encloses a processor 102 , a digital memory 104 , and other components as appropriate to produce the desired functionalities of the device. In various embodiments, AIMD 100 is implemented as any implanted medical device capable of measuring the heart rate of a patient and a ventricular or arterial pressure signal, including, but not limited to a pacemaker, defibrillator, electrocardiogram monitor, blood pressure monitor, drug pump, insulin monitor, or neurostimulator. An example of a suitable AIMD that may be used in various exemplary embodiments is the CHRONICLE® implantable hemodynamic monitor (IHM) device available from Medtronic, Inc. of Minneapolis, Minn., which includes a mechanical sensor capable of detecting a pressure signal.
[0048] In a further embodiment, AIMD 100 comprises any device that is capable of sensing a pressure signal and providing pacing and/or defibrillation or other electrical stimulation therapies to the heart. Another example of an AIMD capable of sensing pressure-related parameters is described in commonly assigned U.S. Pat. No. 6,438,408B1 issued to Mulligan et al. on Aug. 20, 2002.
[0049] Processor 102 may be implemented with any type of microprocessor, digital signal processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other integrated or discrete logic circuitry programmed or otherwise configured to provide functionality as described herein. Processor 102 executes instructions stored in digital memory 104 to provide functionality as described below. Instructions provided to processor 102 may be executed in any manner, using any data structures, architecture, programming language and/or other techniques. Digital memory 104 is any storage medium capable of maintaining digital data and instructions provided to processor 102 such as a static or dynamic random access memory (RAM), or any other electronic, magnetic, optical or other storage medium.
[0050] As further shown in FIG. 3 , AIMD 100 may receive one or more cardiac leads for connection to circuitry enclosed within the housing. In the example of FIG. 3 , AIMD 100 receives a right ventricular endocardial lead 118 , a left ventricular coronary sinus lead 122 , and a right atrial endocardial lead 120 , although the particular cardiac leads used will vary from embodiment to embodiment. In addition, the housing of AIMD 100 may function as an electrode, along with other electrodes that may be provided at various locations on the housing of AIMD 100 . In alternate embodiments, other data inputs, leads, electrodes and the like may be provided. Ventricular leads 118 and 122 may include, for example, pacing electrodes and defibrillation coil electrodes (not shown) in the event AIMD 100 is configured to provide pacing, cardioversion and/or defibrillation. In addition, ventricular leads 118 and 122 may deliver pacing stimuli in a coordinated fashion to provide biventricular pacing, cardiac resynchronization, extra systolic stimulation therapy or other therapies. AIMD 100 obtains pressure data input from a pressure sensor that is carried by a lead such as right ventricular endocardial lead 118 . AIMD 100 may also obtain input data from other internal or external sources (not shown) such as an oxygen sensor, pH monitor, accelerometer or the like.
[0051] In operation, AIMD 100 obtains data about heart 120 via leads 118 , 120 , 122 , and/or other sources. This data is provided to processor 102 , which suitably analyzes the data, stores appropriate data in memory 104 , and/or provides a response or report as appropriate. Any identified cardiac episodes (e.g. an arrhythmia or heart failure decompensation) can be treated by intervention of a physician or in an automated manner. In various embodiments, AIMD 100 activates an alarm upon detection of a cardiac event or a detected malfunction of the AIMD. Alternatively or in addition to alarm activation, AIMD 100 selects or adjusts a therapy and coordinates the delivery of the therapy by AIMD 100 or another appropriate device. Optional therapies that may be applied in various embodiments may include drug delivery or electrical stimulation therapies such as cardiac pacing, resynchronization therapy, extra systolic stimulation, neurostimulation.
[0052] FIG. 4 is a block diagram summarizing the data acquisition and processing functions appropriate for practicing the invention. The functions shown in FIG. 4 may be implemented in an AIMD system, such as AIMD 100 shown in FIG. 3 . Alternatively, the functions shown in FIG. 4 may be implemented in an external monitoring system that includes sensors coupled to a patient for acquiring pressure signal data. The system includes a data collection module 206 , a data processing module 202 , a response module 218 and/or a reporting module 220 . Each of the various modules may be implemented with computer-executable instructions stored in memory 104 and executing on processor 102 (shown in FIG. 3 ), or in any other manner.
[0053] The exemplary modules and blocks shown in FIG. 4 are intended to illustrate one logical model for implementing an AIMD 100 , and should not be construed as limiting. Indeed, the various practical embodiments may have widely varying software modules, data structures, applications, processes and the like. As such, the various functions of each module may in practice be combined, distributed or otherwise differently-organized in any fashion across a patient monitoring system. For example, a system may include an implantable pressure sensor and EGM circuit coupled to an AIMD used to acquire pressure and EGM data, an external device in communication with the AIMD to retrieve the pressure and EGM data and coupled to a communication network for transferring the pressure and EGM data to a remote patient management center for analysis. Examples of remote patient monitoring systems in which aspects of the present invention could be implemented are generally disclosed in U.S. Pat. No. 6,497,655 issued to Linberg and U.S. Pat. No. 6,250,309 issued to Krichen et al., both of which patents are incorporated herein by reference in their entirety.
[0054] Pressure sensor 210 may be deployed in an artery for measuring an arterial pressure signal or in the left or right ventricle for measuring a ventricular pressure signal. In some embodiments, pressure sensor 210 may include multiple pressure sensors deployed at different arterial and/or ventricular sites. Pressure sensor 210 may be embodied as the pressure sensor disclosed in commonly assigned U.S. Pat. No. 5,564,434, issued to Halperin et al., hereby incorporated herein in its entirety.
[0055] Data sources 207 may include other sensors 212 for acquiring physiological signals useful in monitoring a cardiac condition such as an accelerometer or wall motion sensor, a blood flow sensor, a blood gas sensor such as an oxygen sensor, a pH sensor, or impedance sensors for monitoring respiration, lung wetness, or cardiac chamber volumes. The various data sources 207 may be provided alone or in combination with each other, and may vary from embodiment to embodiment.
[0056] Data collection module 206 receives data from each of the data sources 207 by polling each of the sources 207 , by responding to interrupts or other signals generated by the sources 207 , by receiving data at regular time intervals, or according to any other temporal scheme. Data may be received at data collection module 206 in digital or analog format according to any protocol. If any of the data sources generate analog data, data collection module 206 translates the analog signals to digital equivalents using an analog-to-digital conversion scheme. Data collection module 206 may also convert data from protocols used by data sources 207 to data formats acceptable to data processing module 202 , as appropriate.
[0057] Data processing module 202 is any circuit, programming routine, application or other hardware/software module that is capable of processing data received from data collection module 206 . In various embodiments, data processing module 202 is a software application executing on processor 102 of FIG. 3 or another external processor.
[0058] Reporting module 220 is any circuit or routine capable of producing appropriate feedback from the AIMD to the patient or to a physician. In various embodiments, suitable reports might include storing data in memory 204 , generating an audible or visible alarm 228 , producing a wireless message transmitted from a telemetry circuit 230 .
[0059] In a further embodiment, the particular response provided by reporting module 220 may vary depending upon the severity of the hemodynamic change. Minor episodes may result in no alarm at all, for example, or a relatively non-obtrusive visual or audible alarm. More severe episodes might result in a more noticeable alarm and/or an automatic therapy response.
[0060] When the functionality diagramed in FIG. 4 is implemented in an AIMD, telemetry circuitry 230 is included for communicating data from the AIMD to an external device adapted for bidirectional telemetric communication with AIMD. The external device receiving the wireless message may be a programmer/output device that advises the patient, a physician or other attendant of serious conditions (e.g., via a display or a visible or audible alarm). Information stored in memory 204 may be provided to an external device to aid in diagnosis or treatment of the patient. Alternatively, the external device may be an interface to a communications network such that the AIMD is able to transfer data to an expert patient management center or automatically notify medical personnel if an extreme episode occurs.
[0061] Response module 218 comprises any circuit, software application or other component that interacts with any type of therapy-providing system 224 , which may include any type of therapy delivery mechanisms such as a drug delivery system, neurostimulation, and/or cardiac stimulation. In some embodiments, response module 218 may alternatively or additionally interact with an electrical stimulation therapy device that may be integrated with an AIMD to deliver pacing, extra systolic stimulation, cardioversion, defibrillation and/or any other therapy. Accordingly, the various responses that may be provided by the system vary from simple storage and analysis of data to actual provision of therapy in various embodiments.
[0062] The various components and processing modules shown in FIG. 4 may be implemented in an AIMD 100 (e.g., as depicted in FIG. 1 or 3 ) and housed in a common housing such as that shown in FIG. 3 . Alternatively, functional portions of the system shown in FIG. 4 may be housed separately. For example, portions of the therapy delivery system 224 could be integrated with AIMD 100 or provided in a separate housing, particularly where the therapy delivery system includes drug delivery capabilities. In this case, response module 218 may interact with therapy delivery system 224 via an electrical cable or wireless link.
[0063] FIGS. 5 A-B are plan views of medical electrical leads according to alternate embodiments of the present invention. FIG. 5A illustrates a lead 10 including a lead body 11 having a proximal portion 12 and a distal portion 13 ; distal portion 13 includes a distal tip 14 , to which a fixation element 15 and a cathode tip electrode 16 are coupled, a defibrillation electrode 19 positioned proximal to distal tip 14 and a sensor 17 positioned proximal to defibrillation electrode 19 . FIG. 5B illustrates a lead 100 also including lead body 11 , however, according to this embodiment, sensor 17 is positioned distal to defibrillation electrode 19 and distal tip 14 further includes an anode ring electrode 18 and cathode tip electrode 16 is combined into fixation element 15 . Appropriate cathode electrode, anode electrode and defibrillation electrode designs known to those skilled in the art may be incorporated into embodiments of the present invention. Although FIGS. 5 A-B illustrate proximal portion 12 including a second defibrillation electrode 20 , embodiments of the present invention need not include second defibrillation electrode 20 . For those embodiments including defibrillation electrode 20 , electrode 20 is positioned along lead body such that electrode 20 is located in proximity to a junction between a superior vena cava 310 and a right atrium 300 when distal portion 13 of lead body 11 is implanted in a right ventricle 200 ( FIG. 3 ). Additionally, tip electrode 16 and ring electrode 18 are not necessary elements of embodiments of the present invention.
[0064] FIGS. 5 A-B illustrate fixation element 15 as a distally extending helix, however element 15 may take on other forms, such as tines or barbs, and may extend from distal tip 14 at a different position and in a different direction, so long as element 15 couples lead body 11 to an endocardial surface of the heart in such a way to accommodate positioning of defibrillation electrode 19 and sensor 17 appropriately.
[0065] According to alternate embodiments of the present invention, sensor 17 is selected from a group of physiological sensors, which should be positioned in high flow regions of a circulatory system in order to assure proper function and long term implant viability of the sensor; examples from this group are well known to those skilled in the art and include, but are not limited to oxygen sensors, pressure sensors, flow sensors and temperature sensors. Commonly assigned U.S. Pat. No. 5,564,434 describes the construction of a pressure and temperature sensor and means for integrating the sensor into an implantable lead body. Commonly assigned U.S. Pat. No. 4,791,935 describes the construction of an oxygen sensor and means for integrating the sensor into an implantable lead body. The teachings U.S. Pat. Nos. 5,564,434 and 4,791,935, which provide means for constructing some embodiments of the present invention, are incorporated by reference herein.
[0066] FIGS. 5 A-B further illustrates lead body 11 joined to connector legs 2 via a first transition sleeve 3 and a second transition sleeve 4 ; connector legs 2 are adapted to electrically couple electrodes 15 , 16 , 19 and 20 and sensor 17 to an AIMD in a manner well known to those skilled in the art. Insulated electrical conductors, not shown, coupling each electrode 15 , 16 , 19 and 20 and sensor 17 to connector legs 2 , extend within lead body 11 . Arrangements of the conductors within lead body 11 include coaxial positioning, non-coaxial positioning and a combination thereof; according to one exemplary embodiment, lead body 11 is formed in part by a silicone or polyurethane multilumen tube, wherein each lumen carries one or more conductors.
[0067] FIG. 6 is a cross sectional view of a coaxial conductive lead body 11 adapted for operative coupling proximal of a sensor capsule taken along the line 6 - 6 of FIG. 5B according to the invention. In FIG. 6 , an inner conductor 50 is spaced from an outer conductor 52 with an insulative material 54 disposed therebetween. The exterior of the biocompatible outer insulation 56 of the lead body 11 shields the conductors 50 , 52 from contact with conductive body fluid. One aspect of the instant invention involves failure of the outer insulation 56 and ways to render such a failure essentially innocuous to a patient.
[0068] FIG. 7 is a schematic illustration of a sensor capsule 17 coupled to a housing 100 of an IMD and a source of reference potential 53 according to certain embodiments of the invention described herein.
[0069] FIG. 8 . is a schematic view of a sensor capsule 17 coupled to a electrical current detector 55 and operative circuitry housed within an IMD 100 . As described herein in the event that excess current is detected energy for the sensor capsule 17 can be interrupted, either permanently or temporarily.
[0070] FIG. 9 is a schematic view of an IMD 100 having a proximal lead-end set screw 13 for mechanically retaining the proximal end of a medical electrical lead 11 within a connector block 57 , wherein said set screw couples to a source of reference potential 53 . The set screw can also promote electrical communication between conductors on the proximal end of the lead 11 and corresponding conductive portions of the connector block 57 . The conductive portions connect via hermetically sealed conductive feedthrough pins to operative circuitry within the IMD 100 .
[0071] Employing the foregoing methods and apparatus and equivalents thereof, a variety of component failures can be selectively retested and possibly restored by energizing an implantable physiologic sensor (IPS) at relatively low voltages and/or during periods of time when adjacent tissue is non-excitatory (e.g., the absolute and/or relative refractory period for myocardial tissue). The relatively low voltages help ensure that in the event electrical energy is restored to an IPS and adjacent tissue is in fact in an excitable state, an inadvertent delivery of energy to the tissue might not capture (i.e., evoke a response). In the event that the adjacent tissue comprises myocardial tissue, a threshold indicating failure during a retest can include a direct current (dc) of about 9.5 or 10 microamps. Alternately, if an impedance measurement reveals very high impedance in the IPS circuitry (e.g., 10 megaohms) likely no errant electrical currents are being inadvertently delivered via the IPS.
[0072] A retesting regimen can include a period of time between successive retesting episodes (e.g., several minutes, hours, etc.). In order to declare a previously detected errant current flow episode absent, confirmation criteria can require several successive successful retesting sequences (e.g., three-of-three, etc.). Such criteria helps mitigate the possibility of noise (i.e., improves noise rejection). In addition, in the case an IPG includes activity sensing capability the then-present heart rate and/or activity sensor output signals can be used to select an advantageous time to retest the IPS circuitry.
[0073] Thus, a system and method have been described which provide methods and apparatus for mitigating possible failure mechanisms for AIMDs coupled to chronically implantable sensors. Aspects of the present invention have been illustrated by the exemplary embodiments described herein. Numerous variations for providing such robust structures and methods can be readily appreciated by one having skill in the art having the benefit of the teachings provided herein. The described embodiments are intended to be illustrative of methods for practicing the invention and, therefore, should not be considered limiting with regard to the following claims.
[0074] While exemplary embodiments have been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that these exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide a convenient road map for implementing an exemplary embodiment of the invention. Various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents. | According to the invention, a possible fault scenario involves an insulation breach of a medical lead which couples signals and/or electrical energy between a sensor and a circuit-bearing, active implantable medical device (AIMD). An initial response involves disconnecting the power source from the sensor with subsequent responses including selective reconnection of the power source. If the fault spontaneously resolves, then power to the sensor can be restored and physiologic signals transmitted to operative circuitry of the AIMD. In addition, however, an intermediate mode is enabled with the power source only coupled temporarily, for example, during intervals when stimulation and/or capture of excitable tissue (e.g., myocardial tissue) is not likely to occur due to any electrical shunt current(s). Thus, applying energy to a sensor(s) during the refractory period of a cardiac chamber eliminates undesired tissue activation. Moreover, sensed physiologic parameters can be collected without interrupting therapy delivery | 0 |
This is a continuation of application Ser. No. 07/060,450, filed Jun. 11, 1987.
FIELD OF THE INVENTION
This invention is in the field of plant breeding, specifically hybrid grain sorghum breeding.
BACKGROUND OF THE INVENTION
The goal of plant breeding is to combine in a single variety/hybrid various desirable traits of the parental lines. For field crops, these traits may include resistance to diseases and insects, tolerance to heat, drought and salt, reducing the time to crop maturity, greater yield and yield stability and better agronomic quality. With mechanical harvesting of many crops, uniformity of plant characteristics such as germination and stand establishment, growth rate, maturity, plant height and fruit size, is important.
Field crops are bred through techniques that take advantage of the plant's method of pollination. A plant is self-pollinating if pollen from one flower is transferred to the same or another flower of the same plant. A plant is cross-pollinated if the pollen comes from a flower on a different plant.
Plants that have been self-pollinated and selected for type for many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny. A cross between two homozygous plants from differing backgrounds or two homozygous lines produce a uniform population of hybrid plants that may be heterozygous for many gene loci. A cross of two plants each heterozygous at a number of gene loci will produce a population of hybrid plants that differ genetically and will not be uniform.
Sorghum plants (Sorghum bicolor (L.) Moench) are bred in most cases by self pollination techniques. With the incorporation of male sterility (either genetic or cytoplasmic) cross pollination breeding techniques can also be utilized. Sorghum has a perfect flower with both male and female parts in the same flower located in the panicle. The flowers are usually in pairs on the panicle branches. Natural pollination occurs in sorghum when anthers (male flowers) open and pollen falls onto receptive stigma (female flowers). Because of the close proximity of male (anthers) and female (stigma) in the panicle, self pollination is very high (average 94%). Cross pollination may occur when wind or convection currents move pollen from the anthers of one plant to receptive stigma on another plant. Cross pollination is greatly enhanced with incorporation of male sterility which renders male flowers nonviable without affecting the female flowers. Successful pollination in the case of male sterile flowers requires cross pollination.
The development of sorghum hybrids requires the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding methods, and to a lesser extent population breeding methods, are used to develop inbred lines from breeding populations. Breeding programs combine desirable traits from two or more inbred lines into breeding pools from which new inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which have commercial potential.
Pedigree breeding starts with the crossing of two genotypes, each of which may have one or more desirable characteristics that is lacking in the other or which complement the other. If the two original parents do not provide all of the desired characteristics, other sources can be included in the breeding population. In the pedigree method, superior plants are selfed and selected in successive generations. In the succeeding generations the heterozygous condition gives way to homogeneous lines as a result of self-pollination and selection. Typically, in the pedigree method of breeding five or more generations of selfing and selection is practiced. F 1 to F 2 ; F 2 to F 3 ; F 3 to F 4 , F 4 to F 5 , etc.
Backcrossing can be used to improve an inbred line. Backcrossing transfers a specific desirable trait from one inbred or source to an inbred that lacks that trait. This can be accomplished for example by first crossing a superior inbred (A) (recurrent parent) to a donor inbred (non-recurrent parent), which carries the appropriate genes(s) for the trait in question. The progeny of this cross is then mated back to the superior recurrent parent (A) followed by selection in the resultant progeny for the desired trait to be transferred from the non-recurrent parent. After five or more backcross generations with selection for the desired trait, the progeny will be heterozygous for loci controlling the characteristic being transferred, but will be like the superior parent for most or almost all other genes. The last backcross generation would be selfed to give pure breeding progeny for the gene(s) being transferred.
A hybrid sorghum variety is the cross of two inbred lines, each of which may have one or more desirable characteristics lacked by the other or which complement the other. The hybrid progeny of the first generation is designated F 1 . In the development of hybrids only the F 1 hybrid plants are sought. The T 1 F hybrid is more vigorous than its inbred parents. This hybrid vigor, or heterosis, can be manifested in many ways, including increased vegetative growth and increased yield.
The development of a hybrid sorghum variety involves five steps: (1) the formation of "restorer" and "non-restorer" germplasm pools; (2) the selection of superior plants from various "restorer" and "non-restorer" germplasm pools; (3) the selfing of the superior plants for several generations to produce a series of inbred lines, which although different from each other, each breed true and are highly uniform; (4) the conversion of inbred lines classified as non-restorers to cytoplasmic male sterile (CMS) forms, and (5) crossing the selected cytoplasmic male sterile (CMS) inbred lines with selected fertile inbred lines (restorer lines) to produce the hybrid progeny (F 1 ).
Because sorghum is normally a self pollinated plant and because both male and female flowers are in the same panicle, large numbers of hybrid seed can only be produced by using cytoplasmic male sterile (CMS) inbreds. Flowers of the CMS inbred are fertilized with pollen from a male fertile inbred carrying genes which restore male fertility in the hybrid (F 1 ) plants. An important consequence of the homozygosity and homogeneity of the inbred lines is that the hybrid between any two inbreds will always be the same. Once the inbreds that give the best hybrid have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parent is maintained.
A single cross hybrid is produced when two inbred lines are crossed to produce the 1 progeny. Much of the hybrid vigor exhibited by F 1 hybrids is lost in the next generation (F 2 ). Consequently, seed from hybrid varieties is not used for planting stock.
Hybrid grain sorghum can be produced using wind to move the pollen. Alternating strips of the cytoplasmic male sterile inbred (female) and the male fertile inbred (male) are planted in the same field. Wind moves the pollen shed by the male inbred to receptive stigma on the female. Providing that there is sufficient isolation from sources of foreign sorghum pollen, the stigma of the male sterile inbred (female) will be fertilized only with pollen from the male fertile inbred (male). The resulting seed, born on the male sterile (female) plants is therefore hybrid and will form hybrid plants that have full fertility restored.
Grain sorghum is an important and valuable food and feed grain crop. In addition, its vegetative parts are used for forage, syrup and shelter Thus, a continuing goal of plant breeders is to develop stable high yielding sorghum hybrids that are agronomically sound. The reasons for this goal are obvious to maximize the amount of grain produced on the land used and to supply food for both animals and humans.
SUMMARY OF THE INVENTION
According to the invention, there is provided a hybrid grain sorghum plant, designated 8358, produced by crossing two Pioneer Hi-Bred International, Inc., proprietary inbred lines of sorghum. This invention thus relates to the hybrid seed 8358, the hybrid plant produced from the seed, variants, mutants and modifications of Pioneer hybrid 8358. This hybrid sorghum plant is characterized by superior yields, wide adaptation, excellent biotype C and E greenbug (Schizaphis graminum (Rondani) resistance, excellent anthracnose (Colletotricum graminicola) resistance and excellent resistance to pathotype 1 and 3 downy mildew (Sclerospora sorghi), and races 1, 2, 3 and 4 of head smut (Sphacelotheca reiliana).
DEFINITIONS
In the description and examples that follow, a number of terms are used herein. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:
Predicted RM. This trait, predicted relative maturity (RM), for a hybrid is based on the number of days required for an inbred line or hybrid to shed pollen from the time of planting. The relative maturity rating is based on a known set of checks and utilizes standard linear regression analyses.
Yield/RM. This represents a rating of a hybrid yield compared to other hybrids of similar maturity or RM. A high score would indicate a hybrid with higher yield than other hybrids of the same maturity.
RM to Color. This trait for a hybrid is based on the number of days required for a hybrid to begin to show color development in the grain from the time of planting. The relative maturity rating is based on a known set of checks and utilizes standard linear regression analyses.
Yield (cwt/acre). The yield in cwt/acre is the actual yield of the grain at harvest adjusted to 13% moisture.
Percent Yield. The percent yield is the yield obtained from the hybrid in terms of percent of the mean for the experiment in which it was grown.
Yield Under Stress. This is a rating of the plants ability to produce grain under heat and drought stress conditions. A score of 9 would indicate near normal growth and grain yield and a score of 1 would indicate substantial yield reduction due to stress.
Drought Tolerance. This represents a rating for drought tolerance and is based on data obtained under stress. It is based on such factors as yield, plant health, lodging resistance and stay green. A high score would indicate a hybrid tolerant to drought stress.
Selection Index. The selection index gives a single measure of the hybrid's worth based on information for up to five traits. A sorghum breeder may utilize his or her own set of traits for the selection index. Two of the traits that are almost always included are yield and days to flower (maturity). The selection index data presented in the tables in the specification represent the mean values averaged across testing stations.
Moisture. The moisture is the actual percentage moisture of the grain at harvest.
Test Weight. This is the measure of the weight of the grain in pounds for a given volume (bushel) adjusted for percent moisture.
Dry Down. This represents the relative rate at which a hybrid will reach acceptable harvest moisture compared to other hybrids. A high score indicates a hybrid that dries relatively fast while a low score indicates a hybrid that dries slowly.
Head Exertion. This represents a rating for the length of the peduncle exposed between the base of the panicle (head) and the flag leaf of the plant. A high score indicates more distance between the flag leaf and the sorghum head while a low score indicates a short distance between the two. Head exertion is important for ease of combine harvesting.
Head Type. This represents a rating of the morphology of the sorghum panicle (head). A high score indicates an open panicle caused by either more distance between panicle branches or longer panicle branches. A low score indicates a more compact panicle caused by shorter panicle branches arranged more closely on the central rachis.
Stalk Lodging. This represents a rating of the percentage of plants that do not stalk lodge, i.e. stalk breakage above the ground caused by natural causes. This is a relative rating of a hybrid to other hybrids for standability.
Plant Height. This is a measure of the average height of the hybrid from the ground to the tip of the panicle and is measured in inches.
Root Lodging. This represents a rating of the percentage of plants that do not root lodge, i.e. those that lean from the vertical axis at an approximate 30 degree angle or greater without stalk breakage are considered to be root lodged. This is a relative rating of a hybrid to other hybrids for standability.
Sales Appearance. This represents a rating of the acceptability of the hybrid in the market place. It is a complex score including such factors as hybrid uniformity, appearance of yield, grain texture, grain color and general plant health. A high score indicates the hybrid would be readily accepted based on appearance only. A low score indicates hybrid acceptability to be marginal based on appearance only.
Days to Flower. The days to flower is the number of days required for an inbred line or hybrid to shed pollen from the time of planting.
Days to Color. The days to color is the number of days required for an inbred line or hybrid to begin grain coloring from the time of planting. Coloring of the grain is correlated with physiological maturity, thus days to color gives an estimate of the period required before a hybrid is ready for harvest.
Stay Green. Stay green is the measure of plant health near the time of harvest. A high score indicates better late-season plant health.
Weathering. This represents a rating of how well the exposed grains are able to retain normal seed quality when exposed to normal weather hazards and surface grain molds.
Salt Tolerance. This represents a rating of the plants ability to grow normally in soils having high sodium salt content. This is a relative rating of a hybrid to other hybrids for normal growth.
Rust Resistance. This is a visual rating based on the number of rust pustules present on the leaves and stem of the sorghum plant. A score of 9 would indicate the presence of few rust pustules.
Anthracnose Resistance. This is a visual rating based on the number of lesions caused by anthracnose infection. A score of 9 would indicate little necrosis and a score of 1 would indicate plant death as a result of anthracnose infection.
Head Smut Resistance (Races 1-4). This is a visual rating based on the percentage of smut infected plants. A score of 9 would indicate no infected plants and a score of 1 would indicate higher than 50% infected plants. Ratings are made for each race of head smut.
Downy Mildew Resistance (Pathotypes 1 and 3). This is a visual rating based on the percentage of downy mildew infected plants. A score of 9 indicates no infected plants. A score of 1 would indicate higher than 50% infected plants. Ratings are made for infection by each pathotype of the disease.
Gray Leaf Spot Resistance. This is a visual rating based on the number of gray leaf spot lesions present on the leaves and stem of the sorghum plant. A score of 9 would indicate the presence of few lesions.
Zonate Leaf Spot Resistance. This is a visual rating based on the number of zonate leaf spot lesions present on the leaves and stem of the sorghum plant. A score of 9 would indicate the presence of few lesions.
Leaf Burn Resistance. This is a visual rating based on the amount of tissue damage caused by exposure to insecticide sprays. A score of 9 would indicate minor leaf spotting and a score of 1 would indicate leaf death as a result of contact with insecticide spray.
Maize Dwarf Mosaic Virus Resistance. This is a visual rating based on the percentage of plants showing symptoms of virus infection. A score of 9 would indicate no plants with virus symptoms and a 1 would indicate a high percentage of plants showing symptoms of virus infection such as stunting, red leaf symptoms or leaf mottling.
Midge Resistance. This is a visual rating based on the percentage of seed set in the panicle in the presence of large numbers of midge adults. A score of 9 would indicate near normal seed set and a score of 1 would indicate no seed set in the head due to midge damage.
Chinch Bug Resistance. This is a visual rating based on the plants ability to grow normally when infested with large numbers of chinch bugs. A score of 9 would indicate normal growth and a score of 1 would indicate severe plant stunting and death.
Biotype C Greenbug Resistance. This is a visual rating based on the amount of necrosis on leaves and stems caused by biotype C greenbug feeding. A score of 9 would indicate no leaf or stem damage as a result of greenbug feeding.
Biotype E Greenbug Resistance. This is a visual rating based on plant seedlings ability to continue growing when infested with large numbers of biotype E greenbugs. A score of 9 indicates normal growth and a score of 1 indicates seedling death.
DETAILED DESCRIPTION OF THE INVENTION
Hybrid 8358 is a single cross made with Pioneer Hi-Bred proprietary sorghum inbred lines PH210 and PH232.
To produce 8358, inbred PH210 must be used as the female parent of the cross and inbred PH232 must be used as the male parent of the cross. Production planting should be timed so that the male pollen is shed at the same time that the female stigma are receptive to the pollen. The male inbred will flower and shed pollen 3-6 days earlier than the female flowers and becomes receptive to pollen. Therefore, the planting of the male inbred should be delayed 3-6 days to obtain maximum pollination with the male inbred. The hybrid grain sorghum seed 8358 produced by this cross can then be planted to produce the hybrid plant.
8358 is a late flowering hybrid, broadly adapted to the majority of the sorghum growing areas of the United States. This hybrid has high yield, excellent resistance to pathotype 1 and 3 downy mildew, races 1-4 of head smut and anthracnose. It is also resistant to biotype C and E greenbugs. The hybrid has good stalk and root strength. It is average in height with adequate head exertion and semi-open panicles. Test weight, stay green and weathering qualities are only average The hybrid tends to flower late and then move to maturity very quickly. This ability contributes to its wide area of adaptation and allows it to be grown in states as far north as Nebraska. The hybrid is rated as a 74 RM hybrid based on days to flower and as a 71 RM hybrid based on days to color.
This hybrid has the following characteristics based on descriptive data collected at Plainview, Texas:
______________________________________A. Maturity Days to flower 73 Days to color 98B. Plant Height (to panicle tip) 45 cm Head exertion 3-6 inches Plant color Purple Number of tillers 2-3 Cytoplasm type Male Sterile (A1)C. Leaf Width 4 inches Length 21 inches No. per main stalk 11 Midrib color Cloudy Color pattern Solid Attitude Horizontal Color Dark greenD. Panicle Head type Semi-open Panicle length 5.7 inches Panicle shape Cylindrical Panicle branches Erect Panicle branch length 3 inches Glume color Red Awns AbsentE. Kernel Seed size 14,000-16,000/pound Pericarp color Red Pericarp Opaque Testa Absent Endosperm color White Endosperm texture CorneousF. Disease Resistance Downy mildew - pathotype 1 Tolerant Downy mildew - pathotype 3 Tolerant Maize dwarf mosaic virus Tolerant Head smut - Race 1 Tolerant Head smut - Race 2 Tolerant Head smut - Race 3 Tolerant Head smut - Race 4 Tolerant Gray leaf spot Intermediate Zonate leaf spot Intermediate Anthracnose Tolerant Rust Intermediate Charcoal rot Tolerant Fusarium stalk rot TolerantG. Insect Resistance Greenbugs - biotype C Tolerant Greenbugs - biotype E Tolerant Chinch bugs Susceptible Sorghum midge Susceptible______________________________________
This invention includes the hybrid sorghum seed of 8358, the hybrid grain sorghum plant produced from the hybrid sorghum seed, and variants, modification and mutants of 8358.
The terms variants, modification and mutant refer to a hybrid seed or a plant produced by that hybrid seed which is phenotypically similar to 8358.
As used herein, the term "plant" includes plant cells, plant protoplasts, plant cell or tissue culture from which sorghum plants can be regenerated, plant calli, plant clumps and plant cells that are intact in plants or parts of plants such as flowers, kernels, panicles, leaves, stalks and the like. Sorghum tissue culture techniques are described in Bright and Jones, Cereal Tissue and Cell Culture, chapter 6, (Martinus Nijnoff/Dr. W. Junk, Amsterdam) on pages 176-203.
USES OF SORGHUM
Sorghum is used as livestock feed, as human food, and as raw material in industry. The most common use of sorghum grain in the United States is as livestock feed, primarily to beef cattle, dairy cattle, hogs and poultry. The sorghum plant is also used as livestock feed in the form of fodder, silage, hay and pasture.
Sorghum grain is most important as human food in areas outside the United States. In these areas, the grain is consumed in the form of bread, porridge, confectionaries and as an alcoholic beverage Grain sorghum may be ground into flour and either used directly or blended with wheat or corn flour in the preparation of food products. In addition to direct consumption of the grain, sorghum has long been used in many areas of the world to make beer. The of uses of sorghum, in addition to human consumption of kernels, include both products of dry--and wet--milling industries. The principle products of sorghum dry milling are grits, meal and flour. Starch and other extracts for food use can be provided by the wet milling process.
Sorghum provides a source of industrial raw material. Industrial uses are mainly from sorghum starch from the wet-milling industry and sorghum flour from the dry milling industry. Sorghum starch and flour have application in the paper and textile industries. Other industrial uses include applications in adhesives, building materials and as oil-well muds. Considerable amounts of sorghum, both grain and plant material, have been used in industrial alcohol production.
The seed of hybrid 8358, the hybrid sorghum plant produced from the seed, and various parts of the hybrid sorghum plant can be utilized for human food, livestock feed, and as a raw material for industry.
EXAMPLES
In the examples that follow, the traits and characteristics of 8358 are given. The history of this hybrid is as follows: the hybrid was first made at the Pioneer Hi-Bred International, lnc., Kingston Research Station in Kingston, Jamaica. Jamaica serves as a winter nursery site for research stations located in the United States. In the first year (1982), the experimental cross was tested in elite trials at the following sorghum research stations: Plainview, Texas; Hutchinson, Kansas; and York, Nebraska. Along with 8358; 1,940 non-specialty hybrids were evaluated. Of these 1,940 hybrids, 633 were wide area hybrids. A total of 81 replications or "reps" (one experiment/one location/one time) of yield test data were collected on the hybrid for some traits.
Additional hybrid seed was produced by several research stations including Plainview, Texas; Hutchinson, Kansas; and York, Nebraska. There was some seed produced for Plainview at Pioneer's Kingston, Jamaica location (winter nursery).
In the second year trials, the hybrid was tested widely in research trials, including testing in South Texas, and 90 replications of yield test data were collected on some agronomic traits. In conjunction with the yield testing, the hybrid was also included in disease and insect tests to determine its relative performance to known hybrids.
In the third year trials, 8358 was tested widely in research trials and 102 replications of data were collected for important traits. Again, the hybrid was evaluated in disease and insect tests.
In the fourth year, the hybrid was evaluated over a wide area in replicated tests. A total of 172 additional replications of data were collected in advanced trials. The hybrid was also widely tested in strip tests across the United States in its area of adaptation. Again, this hybrid was evaluated for tolerance to diseases and insects as compared to known hybrids.
In the examples that follow, the data collected on hybrid 8358 is presented for the key characteristics and traits. The scores are on a scale of 1 to 9, with 9 being the best unless otherwise indicated. The scores based on extensive testing are subjective in nature, but include input from expert sorghum researchers.
EXAMPLE I
Comparison of Various Sorghum Hybrid Characteristics
Comparison of the characteristics of 8358 were made against Pioneer brand hybrids 8333 and 8222, sorghum hybrids developed and marketed by applicant in the same maturity zone as 8358.
Comparison of the characteristics of 8358 was also made against Funks G1711 and FUNKS G522DR sorghum hybrids. The result of these comparisons are given in Tables IA through ID.
TABLE IA__________________________________________________________________________COMPARISONS OF HYBRIDS 8358 AND FUNKS G522DR FROM PERIOD OF YEARSRESEARCH DATA__________________________________________________________________________ PREDICTED SELECTION PERCENT YIELD TEST HEAD HEADHYBRID RM INDEX YIELD CWT/AC MOISTURE WEIGHT EXERTION TYPE__________________________________________________________________________REPS 262 402 402 402 381 129 352 3468358 73 103 103 55 102 101 97 998333 71 100 102 55 101 100 91 111DIFF. 2 3 1 0 1 1 6 12__________________________________________________________________________ DAYS DAYS STALK PLANT SALES TO TO STAYHYBRID LODGING HEIGHT LODGING APPEARANCE FLOWER COLOR GREEN WEATHERING__________________________________________________________________________REPS 75 345 21 420 408 305 18 128358 106 99 100 114 102 100 97 998333 107 97 94 98 101 102 107 102DIFF. 1 2 6 16 1 2 10 3__________________________________________________________________________ GRAY ZONATE MAIZE DOWNY LEAF LEAF LEAF DWARF SALT HEAD MILDEW SPOT BURN SPOT MOSAICHYBRID TOLERANCE RUST ANTHRACNOSE SMUT PATH 1 SCORE SCORE SCORE VIRUS__________________________________________________________________________REPS 6 23 14 8 16 1 4 16 28358 130 95 134 112 118 82 73 93 1358333 111 124 81 110 109 123 77 124 77DIFF. 19 29 53 2 9 41 4 31 58__________________________________________________________________________ STATIONS TESTED: NORTH PLATTE, NEBRASKA HUTCHINSON, KANSAS PLAINVIEW, TEXAS TAFT, TEXAS
TABLE IB__________________________________________________________________________COMPARISONS OF HYBRIDS 8358 AND FUNKS G1711 FROM PERIOD OF YEARS RESEARCHDATA__________________________________________________________________________ PREDICTED SELECTION PERCENT YIELD TEST HEAD HEADHYBRID RM INDEX YIELD CWT/AC MOISTURE WEIGHT EXERTION TYPE__________________________________________________________________________REPS 127 225 225 225 210 99 205 2058358 73 103 102 58 101 101 98 101G1711 72 105 105 60 101 100 95 88DIFF. 1 2 3 2 0 1 3 13__________________________________________________________________________ DAYS DAYS STALK PLANT ROOT SALES TO TO STAYHYBRID LODGING HEIGHT LODGING APPEARANCE FLOWER COLOR GREEN WEATHERING__________________________________________________________________________REPS 18 213 18 231 227 188 18 38358 108 98 100 106 101 99 98 101G1711 98 103 79 112 100 101 81 91DIFF. 10 5 21 6 1 2 17 10__________________________________________________________________________ GRAY ZONATE MAIZE DOWNY LEAF LEAF LEAF DWARF SALT HEAD MILDEW SPOT BURN SPOT MOSAICHYBRID TOLERANCE RUST ANTHRACNOSE SMUT PATH 1 SCORE SCORE SCORE VIRUS__________________________________________________________________________REPS 4 23 9 2 4 1 2 5 18358 130 102 134 112 118 82 73 93 135G1711 68 80 113 98 109 112 100 106 100DIFF. 72 22 21 14 9 20 27 13 35__________________________________________________________________________ STATIONS TESTED: NORTH PLATTE, NEBRASKA HUTCHINSON, KANSAS PLAINVIEW, TEXAS TAFT, TEXAS
TABLE IC__________________________________________________________________________COMPARISONS OF HYBRIDS 8358 AND 8222 FROM PERIOD OF YEARS RESEARCH__________________________________________________________________________DATA PREDICTED SELECTION PERCENT YIELD TEST HEAD HEADHYBRID RM INDEX YIELD CWT/AC MOISTURE WEIGHT EXERTION TYPE__________________________________________________________________________REPS 118 192 192 192 177 51 166 1668358 73 104 103 59 101 101 100 978222 73 101 103 59 101 102 90 100DIFF. 0 3 0 0 0 1 10 3__________________________________________________________________________ DAYS DAYS STALK PLANT ROOT SALES TO TO STAYHYBRID LODGING HEIGHT LODGING APPEARANCE FLOWER COLOR GREEN WEATHERING__________________________________________________________________________REPS 42 168 6 207 203 131 3 98358 105 99 87 114 102 99 114 978222 106 98 105 103 102 101 125 117DIFF. 1 1 18 11 0 2 11 20__________________________________________________________________________ GRAY ZONATE MAIZE DOWNY LEAF LEAF LEAF DWARF SALT HEAD MILDEW SPOT BURN SPOT MOSAICHYBRID TOLERANCE RUST ANTHRACNOSE SMUT PATH 1 SCORE SCORE SCORE VIRUS__________________________________________________________________________REPS 3 2 12 2 4 1 4 4 18358 130 87 134 112 118 82 73 93 1358222 125 134 104 107 104 75 103 143 174DIFF. 5 47 30 5 14 7 30 50 39__________________________________________________________________________ STATIONS TESTED: NORTH PLATTE, NEBRASKA HUTCHINSON, KANSAS PLAINVIEW, TEXAS TAFT, TEXAS
TABLE ID__________________________________________________________________________COMPARISONS OF HYBRIDS 8358 AND 8333 FROM PERIOD OF YEARS RESEARCH__________________________________________________________________________DATA PREDICTED SELECTION PERCENT YIELD TEST HEAD HEADHYBRID RM INDEX YIELD CWT/AC MOISTURE WEIGHT EXERTION TYPE__________________________________________________________________________REPS 262 402 402 402 381 129 352 3468358 73 103 103 55 102 101 97 998333 71 100 102 55 101 100 91 111DIFF. 2 3 1 0 1 1 6 12__________________________________________________________________________ DAYS DAYS STALK PLANT ROOT SALES TO TO STAYHYBRID LODGING HEIGHT LODGING APPEARANCE FLOWER COLOR GREEN WEATHERING__________________________________________________________________________REPS 75 345 21 420 408 305 18 128358 106 99 100 114 102 100 97 998333 107 97 94 98 101 102 107 102DIFF. 1 2 6 16 1 2 10 3__________________________________________________________________________ GRAY ZONATE MAIZE DOWNY LEAF LEAF LEAF DWARF SALT HEAD MILDEW SPOT BURN SPOT MOSAICHYBRID TOLERANCE RUST ANTHRACNOSE SMUT PATH 1 SCORE SCORE SCORE VIRUS__________________________________________________________________________REPS 6 23 14 8 16 1 4 16 28358 130 95 134 112 118 82 73 93 1358333 111 124 81 110 109 123 77 124 77DIFF. 19 29 53 2 9 41 4 31 58__________________________________________________________________________ STATIONS TESTED: NORTH PLATTE, NEBRASKA HUTCHINSON, KANSAS PLAINVIEW, TEXAS TAFT, TEXAS
EXAMPLE II
Strip Test Data
Comparison data was collected from strip tests that were grown by farmers. Each hybrid was grown in strips of 4, 6, 8, 12, etc. rows in fields depending on size of the planter used. The data were collected from strip tests that had the hybrids in the same field. At harvest, the grain was harvested from a measured area and weighed. The moisture percentage was determined to compute yield and bushels per acre was adjusted to 13% moisture. Each replication or "rep" represents a distinct field.
Comparison strip testing was done between 8358 and Pioneer brand 8333 and 8222. Comparison strip testing was also done between 8358 and Funks G1711 and Funks G522DR.
The results are presented in Tables IIA. Traits characterized on the strip test data in addition to those defined previously are as follows:
Number of Wins. For yield, this number represents the number of times a given hybrid won the comparison.
______________________________________COMPARISONS OF HYBRID 8358 WITH 8222, 8333,FUNKS 522DR AND FUNKS 1711 FROM 1986STRIP TEST DATA No. No. Yield of Lodge Test Reps. Lbs/ac Wins Moisture Score Weight______________________________________8358 4 6962.5 1 14.7 9 61.08222 7252.7 3 15.4 9 61.58358 58 6773 29 15.8 9 58.68333 6765 29 15.6 8 58.48358 2 6203.7 2 13.9 60.0Funks 522DR 5664.2 0 14.2 59.58358 3 6798.4 1 14.2 59.0Funks 1711 6833.4 2 14.3 60.0______________________________________
EXAMPLE III
Comparison of Key Traits
Characteristics of hybrid 8358 were compared to Pioneer brand hybrids 8333 and 8222 for key traits. Table IIIA gives the comparison characteristics for 8358 compared to Pioneer brand hybrids 8333 and 8222. Table IIIB gives comparison characteristics for 8358 compared to Funks 522DR and Funks 1711 hybrids. These data were compiled utilizing the research data for each of the hybrids that are listed. The ratings given for most of the traits are on a 1 to 9 scale. In these cases, 9 would be outstanding, while a 1 would be poor for the given characteristic. The values are based on performance of the given hybrid relative to other Pioneer commercial and pre-commercial hybrids.
The traits characterized in Table IIIA and Table IIIB were defined previously. Disease and insect resistance are rated in Table IIIA and Table IIIB. A score of 9 indicates outstanding resistance, while a score of 1 indicates that the hybrid is very susceptible to the disease or insect given. The diseases and insects tested include pathotypes 1 and 3 of downy mildew, maize dwarf mosaic virus (MDMV), races 1-4 of head smut (head smut 1, head smut 2, etc), gray leaf spot, zonate leaf spot, anthracnose, rust, biotypes C and E greenbugs, chinch bugs and midge.
TABLE 111A__________________________________________________________________________CHARACTERISTIC OF HYBRIDS 8358, 8333 AND 8222 FOR KEY TRAITS__________________________________________________________________________ RM RM YIELD TO TO UNDER HEIGHT DRY STALK ROOTHYBRID FLOWER COLOR YIELD/RM STRESS UNIFORMITY DOWN LODGING LODGING__________________________________________________________________________8358 73 71 7 7 8 8 8 68333 72 72 7 6 9 5 7 68222 73 72 7 6 8 6 9 9__________________________________________________________________________ DOWNY DOWNY MILDEW MILDEW HEAD HEAD HEAD HEAD STAY DROUGHT PATH PATH SMUT SMUT SMUT SMUTHYBRID GREEN TOLERANCE 1 3 MDMV 1 2 3 4__________________________________________________________________________8358 5 7 9 9 8 9 9 98333 5 5 9 9 5 9 9 9 98222 7 5 9 9 9 9 9 9 9__________________________________________________________________________ GRAY ZONATE LEAF LEAF GREENBUGS GREENBUGS CHINCHHYBRID SPOT SPOT ANTHRACNOSE RUST BIO C BIO E BUGS MIDGE__________________________________________________________________________8358 5 5 8 5 9 9 1 18333 7 7 4 7 9 3 1 18222 3 7 6 7 3 3 1 1__________________________________________________________________________
TABLE 111B__________________________________________________________________________CHARACTERISTIC OF HYBRIDS 8358, G1711 AND G522DR FOR KEY__________________________________________________________________________TRAITS RM RM YIELD TO TO UNDER HEIGHT DRY STALK ROOTHYBRID FLOWER COLOR YIELD/RM STRESS UNIFORMITY DOWN LODGING LODGING__________________________________________________________________________8358 73 71 7 7 8 8 8 6G1711 72 73 9 6 5 4 3 1G522DR 71 71 7 7 6 5 7 7__________________________________________________________________________ DOWNY DOWNY MILDEW MILDEW HEAD HEAD HEAD HEAD STAY DROUGHT PATH PATH SMUT SMUT SMUT SMUTHYBRID GREEN TOLERANCE 1 3 MDMV 1 2 3 4__________________________________________________________________________8358 5 7 9 9 8 9 9 9 9G1711 5 5 8 4 5 9 9 9 9G522DR 5 6 8 2 8 9 9 9 9__________________________________________________________________________ GRAY ZONATE LEAF LEAF GREENBUGS GREENBUGS CHINCHHYBRID SPOT SPOT ANTHRACNOSE RUST BIO C BIO E BUGS MIDGE__________________________________________________________________________8358 5 5 8 5 9 9 1 1G1711 7 7 4 3 8 1 1 1G522DR 8 7 4 3 1 1 1 1__________________________________________________________________________ | According to the invention, there is provided a hybrid sorghum plant, designated 8358, produced by crossing two Pioneer Hi-Bred International, Inc., proprietary inbred lines of sorghum. This invention thus relates to the hybrid seed 8358, the hybrid plant produced from the seed, variants, mutants, and modifications of Pioneer hybrid 8358. This hybrid sorghum plant is characterized by superior yields, wide adaptation, excellent biotype C and E greenbug (Schizaphis graminum) resistance, excellent anthracnose (Colletotricum graminicola), resistance and excellent resistance to pathotype 1 and 3 downy mildew (Sclerospora sorghi) and races 1, 2, 3 and 4 of head smut (Spaoelotheca reiliana). | 0 |
BACKGROUND OF THE INVENTION
The present invention relates in general to electron beam evaporators and more particularly to such evaporators having beam spot control.
DESCRIPTION OF THE PRIOR ART
Heretofore, it has been proposed to employ one pair of auxiliarly pole piece structures projecting inwardly from a pair of main pole piece structures of an electron beam evaporator to provide a magnetic lens for adjusting or controlling the beam spot size at the crucible target. It was also suggested that the auxiliary pole piece structures take the form of magnetically permeable screws which would be axially translatable for adjusting the beam spot size. Such an electron beam evaporator structure is disclosed in U.S. Pat. No. 3,483,417 issued Dec. 9, 1969.
It is also known from the prior art to provide a pair of inwardly directed pole piece portions outside of the curved electron beam path for defocusing the electron beam and thus increasing its spot size to increase the rate of evaporation at the higher input powers to the electron gun. Distributing the electron beam energy over a greater area of the surface of the evaporant also minimizes the possibility of ejection of large particles of the evaporant materials, a common problem with sublimable evaporants such as Si, SiO z , C r and the like.
It has also been proposed to electrically adjust the beam spot size at the target crucible by electrically controlling the saturation of a pair of magnetic shunts extending between the main pole piece structures one inside and one outside of the arcuate electron beam path for varying the focusing forces tending to decrease and to increase the spot size on the crucible target.
While the provision of the adjustable magnetic pole pieces on the inside of the electron beam path served to control the magnetic lateral focusing force tending to decrease the spot size of the beam at the target, it is desired to provide a greater control over the beam spot size and more particularly to impart an additional lateral defocusing force that can be preferably controlled or adjusted to derive a wider range of control or adjustment over the beam spot size. While the electromagnetic shunts operating on both the inside and the outside of the beam theoretically provide a wide latitude in the adjustment of the beam spot size, such shunts tend to substantially shunt the main magnetic field which requires the main magnetic to be larger than necessary to achieve the desired magnetic field for focusing of the electron beam. In addition if current were lost or interrupted to either of the shunting magnetic coils, the beam could be misdirected or focused onto more fragile elements within the evaporator causing severe damage thereto.
In addition, prior art systems have included an electromagnet for varying the intensity and shape of the main magnetic field in the region of the electron stream to produce a sweep of the beam spot over the target area. Sweeping the beam spot over the target area, known in the art as "dithering", allows a larger amount of target material to be utilized and is especially useful for sublimable evaporants.
Examples of prior art electron beam heating and/or evaporating devices employing magnetic means for sweeping the beam spot over the target area are disclosed in U.S. Pat. No. 3,235,647 issued Feb. 15, 1966 and U.S. Pat. No. 3,446,934 issued May 27, 1969.
In another prior art device, the beam sweep structure, for sweeping the beam both laterally and longitudinally of the crucible, included a generally U-shaped magnetic core structure with the electon beam being generally centrally disposed of the U-shaped magnetic structure. A magnetic gap was provided between the two side legs of the U-shaped structure and the parallel faces of the adjacent pole pieces of the main transverse beam focus permanent magnet. Coils were wound on the two legs and on the interconnecting member served to increase or decrease the magnetic field in the gap, thereby sweeping the beam spot longitudinally of the crucible. Separately energizing either of the side leg portions relative to the other produced a skewing of the total transverse field in the region of the beam from one direction to the other, thereby providing lateral sweeping of the beam spot over the target crucible.
While these aforecited prior art systems are suitable for sweeping the beam spot across the target area they are relatively bulky and complex.
SUMMARY OF THE PRESENT INVENTION
The principal object of the present invention is the provision of an electron beam evaporator having improved beam spot size and/or sweep control.
In one feature of the present invention, first and second pairs of auxiliary pole piece portions project inwardly from the main beam focus magnetic pole piece structure in the region of the beam path to provide a pair of beam spot lenses for beam spot size conrol and/or for varying the beam spot position relative to the target.
In another feature of the present invention, means are provided for adjusting the intensity and direction of the localized magnetic focusing forces on the electron beam as produced by either or both of the auxiliary pairs of pole piece structures.
In another feature of the pesent invention, the localized forces produced by either or both pairs of auxiliary pole piece structures on the beam is varied by means of varying the current through the electrical coil means magnetically coupled to one or more of the auxiliary pole piece portions for varying the magnetic flux passing through the auxiliary pole piece portion or portions, thereby facilitating control of the beam spot at the target crucible.
Other features and advantages of the present invention will become apparent upon a perusal of the following specification taken in connection with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top elevational view, partly in schematic form, of an electron beam evaporator incorporating features of the present invention,
FIG. 2 is a side elevational view of the structure of FIG. 1 taken along line 2--2 in the direction of the arrows,
FIG. 3 is a schematic sectional view of a portion of the structure of FIG. 1 taken along line 3--3 in the direction of the arrows and showing the focusing and defocusing forces on an electron stream produced by a magnetic lens,
FIG. 4 is a simplified schematic line diagram of a top view of an evaporator, and
FIG. 5 is a plot of evaporation/deposition rate in angstroms per minute versus input power in kilowatts to the electron beam evaportor as a function of the beam spot size at the target crucible.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 there is shown an electron beam evaporator 11 having features of the present invention. The electron beam evaporator 11 includes a solid block 12 of thermally conductive metallic material, as of copper. The opposite sides of the conductive block 12 are recessed at 13 and 14 to receive magnetic pole piece structures or plates 15 and 16, as of magnetic alloy permeable or ferromagnetic material. The pole piece structures 15 and 16 are energized with magnetic flux by means of a transversely directed permanent magnet 17 interconnecting the pole pieces 15 and 16 and passing through a transverse bore 18 in the copper block 12.
A conical recess 19 in the upper side of the copper block 12 serves as a crucible 21 for containing a material 22 to be evaporated. Water coolant channels, not shown, course through the copper block for cooling same in use.
A thermionic directly heated filamentary cathode emitter 23 is contained in the block body structure 12 and the block is recessed at 24 to hold an acclerating anode structure not shown. The anode, located in close proximity to cathode 23 is operated at ground potential and which cooperated with a high negative potential, as of -6 to -14 kV, applied to the filamentary cathode 23 for projecting a ribbon shaped beam of electrons 25 from the cathode 23 through the recess 24 and into an arcuate beam path to the crucible 21. The electrical potential applied between the filamentary cathode 23 and the recessed walls 24 of the body and anode, in cooperation with a strong transverse magnetic field produced between the planar pole structures 15 and 16 causes the beam 25 to take the arcuate path to the crucible. In addition, the fringing magnetic field over the top surface of the block 12 has a certain curvature while facilitates lateral focusing of the electron beam 25 into the crucible 21.
The beam focus magnetic structures includes two pairs of auxiliary pole piece portions 26 and 27, respectively. Pole piece portions 26 comprise, for example, magnetically permeable posts axially aligned on opposite sides of the beam 25 and projecting toward a midplane 28 between the poles 15 and 16, such midplane 28 also being the midplane of the arcuate beam path. In a typical example, the magnetically permable posts 26 are conveniently formed by cap screws, as of cold-rolled steel threaded through tapped bores in the pole pieces 15 and 16. Each pair of pole piece portions 26 and 27 need not be physically separate members but each pair may comprise merely a single magnetically permeable member having a slot or high reluctance gap extending laterally of the member at about its midpoint and corresponding with the center plane 28, so as not to unduly shunt the magnetic flux supplied by the permanent magnet 17.
The first pair of auxiliary pole piece portions 26 are positioned at the upstream end of the beam and inside of the beam path, i.e., on the side of the beam path toward which the arcuate beam is curving. The auxiliary magnetic pole pieces 26 tend to outwardly bow the flux of the main field in a localized region around the high reluctance gap between their inner end portions in the region through which the electron beam 25 passes. Thus, the first set of pole piece portions 26 produce a magnetic beam focusing lens with the beam rising in the y direction through the bowed magnetic field lines as indicated by beam 25 of FIG. 3. More particularly, the beam focus force on the electron beam 25 has two components an F x component tending to either increase or decrease the lateral size of the beam spot and an F z component which causes the beam to bend into its arcuate path to the crucible. The lateral focusing forces, i.e., the F x forces, are produced by the B z components of the magnetic field produced by the curvature (bowing) of the field lines; whereas the main curvature force on the beam is proudced by the transverse main beam focus magnetic field component B x which is in the -x direction. This causes the main curvature force to be in the -z direction, i.e., toward the crucible.
Now with regard to the lateral focusing forces which tend to either increase or decrease the spot size, i.e., the F x forces on beam cross-section 25, there is found to be a +B component at the right end of the beam cross-section 25, there is found to be a -B component at the left end of the beam cross-section 25 such that an inwardly directed force F x is produced at the left end and an inwardly directed force is also produced on the right end. Thus, the beam is focused to a smaller spot size at the crucible.
On the other hand, when the beam cross-section 25' is in the downstream position relative to the inwardly directed pole pieces, as encountered between pole piece portions 27, there is a -B z component on the right end of the cross-section 25' of the beam and a +B z component on the left end of the beam cross-section 25' so that outwardly directed defocusing forces F x are produced on opposite ends of the beam cross-section 25' to defocus the beam spot to a larger spot at the crucible. Thus, the pole piece portions 26 serve to focus the beam spot to a smaller spot size whereas the other pair of pole piece portions 27 serve to focus the beam spot to a larger spot size in the crucible. Relative strengths of the focusing and defocusing forces on the beam spot are adjustable by adjusting the axial gap between the ends of the screws 26 and 27.
Alternatively, and in a preferred embodiment, electrically energizable coils 31 are wound on each of the poles 26. The coils 31 are separately energized via a reversible current derived for example from a potentiometer 32 as connected across a center taped battery 33. In a convenient embodiment, the potentiometer outputs for both poles of the pair are ganged together by means of a mechanical linkage 34 controlled from a front panel knob. In addition, each of the potentiometer settings is independently adjustable for trimming of the focusing forces. By varying the DC energization of the coils 31, the amount of flux passing through each of the poles 26 is adjustable, thereby adjusting the strength and curvature of the field produced between the poles 26. In a similar matter, the field between the outside auxiliary poles 27 may be varied by coupling electrical coils thereto in the manner as described with regard to the poles 26.
In a preferred mode of operation (see FIG. 4 and Table I), the poles 26 and 27 are initially adjusted geometrically without current energization of coils 31 to introduce a net medium defocusing magnetic force tending to produce a medium spot size in the crucible 21.
Tables I and II summarize the relative magnitudes and polarities for the currents indicated in FIG. 4, for controlling spot size and beam steering respectively. In Table I and II, and in FIG. 4, currents greater than 0 mean that the windings through which that particular current flows are such as to produce a component of magnetic field which aids the -B z component produced by the main transverse magnetic field magnet structure in the region of the beam 25. Conversely, when the currents are indicated as being less than zero they are in a direction through the respective coils so as to produce a magnetic field component which tends to buck the main transverse magnetic field component -B X .
In Table I means are disclosed for controlling spot size of the electron beam. With all current = 0, a medium size centered spot results (Table I, 1). When currents in coils 31 surrounding auxiliary poles 26 are greater than 0 and the currents in cils 31 surrounding poles 27 are less than 0 the strength of the main magnetic field, -B x remains nominally unchanged in the region of the beam, thus leaving unchanged the locus of the beam upon the evaporant surface, while achieving a desired curvature of the magnetic field in the manner shown by FIG. 3 and focussing the beam to a smaller spot (Table I, 2). In like manner, a defocussing condition resulting in a larger spot is achieved under the condition given by entry 3 (Table I).
TABLE I______________________________________SPOT SIZE CONTROLCURRENT SPOT SIZE______________________________________1 I.sub.A = I.sub.B =I.sub.C =I.sub.D =0 Medium size spot2 I.sub.A =I.sub.B > 0 (increased magnetic field) I.sub.C = I.sub.D < 0 (decreased magnetic field)3 I.sub.A = I.sub.B < 0 Larger(st) spot I.sub.C = I.sub.D > 0______________________________________
Referring now to FIG. 5 there is shown a plot of evaporation or deposition rate in angstroms per minute versus input power in kilowatts to the electron gun as a function of beam spot size in the crucible 21. More particularly, from the plot it is seen that a maximum evaporation or deposition rate at an input beam power of approximately 6 kilowatts is obtained with a small beam spot size. However, with input beam power of 13 kilowatts, the optimum evaporation or deposition rate occurs for a large spot size. For intermediate input beam powers, intermediate spot sizes yield optimum evaporation or deposition rate. Thus, an advantage of the electron beam evaporator of the present invention is that it readily permits adjustment of the beam spot size in the crucible to yield optimum evaporation or deposition rate for a given input power to the electron gun.
It turns out that the magnetic pole portions 26 and 27, which have been previously described herein for the purpose of controlling the beam spot size, may also be used for sweeping the beam spot 25 laterally and longitudinally over the surface of the crucible. More particularly, the beam 25 may be swept in the longitudinal direction by increasing the current through each of the coils in the magnetic field aiding direction, i.e., -B x , and this will produce an increased transverse magnetic field causing the beam to have increased curvature and to therefore move in the +z direction in the crucible. Likewise if all the currents I A , I B , I C and I D are equal but less than zero, i.e., produce bucking magnetic fields bucking the -B x component the transverse magnetic field will be weakened thereby increasing the radius of curvature of the beam 25 and moving the beam spot 25 in the crucible in the -z direction. The beam may be swept laterally by causing the currents I A and I D to equal and and aiding to the -B x transverse main field while I B and I C are energized to buck -B x to produce a skewing of the field causing the beam spot to move in the -x direction. Similarly, causing the currents I B and I C to be greater than zero, while I A and I D are less than zero, skews the tranverse magnetic field -B x in the opposite direction to cause a lateral deflection of the beam spot 25 in the crucible in the possible x direction. The conditions for longitudinal and lateral sweeping are shown in the lateral sweep Table II below.
TABLE II______________________________________BEAM SPOT SWEEP1 I.sub.A = I.sub.B = I.sub.C = I.sub.D >0 Stronger field Longitudinal movement of +F.sub.z the spot in +z direction2 I.sub.A = I.sub.B = I.sub.C = I.sub.D <0 Weaker field longitudinal movement in F.sub.z -z direction3 I.sub.A = I.sub.D >0 Lateral deflection in the I.sub.B = I.sub.C <0 -x direction -Fx4 I.sub.A = I.sub.D <0 Lateral deflection in the4 I.sub.B = I.sub.C >0 +x direction Fx______________________________________
One of the advantages of the structure of FIGS. 1 and 4 is that the same structure may be utilized both for controlling the beam spot size and for sweeping or moving the spot within the crucible. Thus, by superposition of the proper currents through each of the respective coils or by adjustment of the gap between the respective pole pieces any desired beam spot size and position in the crucible is attainable. By using the electromagnetic version of FIG. 4 all the adjustments can be made electrically from the outside of the bell jar or other chamber in which the evaporator or heater is located, and such adjustment may be effected at rapid periodic rates by electronic means.
With all coil currents = 0, the beam is characterized by a nominal size and centered in the crucible as determined by the magnetic field supplied by the permanent magnet. Failure of any kind resulting in loss of coil currents will therefore cause the beam to revert to this condition because such failure leaves the main field, -B x , unchanged and will therefore not permit displacement of the beam so as to impinge articles being coated or portions of the apparatus with consequent damage, in contrast to prior art apparatus.
It is also apparent that other combinations of coil currents and auxilliary pole placement and designs could be directed to the ends above described. For example, a particular pole piece design and choice of currents could be so chosen as to accomplish all of the features described above wherein the individual coil currents would be characterized by relative magnitudes, having in common the same polarity, thereby achieving significant economy in power supply requirements. | An electron beam evaporator employs an electron gun which projects a beam of electrons over an arcuate beam path to a crucible target for heating and evaporating the target material in use. The electron beam passes through the magnetic field supplied by a pair of pole pieces of a beam focus magnet which produces a main field transverse to the direction of the electrons to cause the beam to take the arcuate trajectory. Two pairs of auxiliary pole pieces project inwardly of the main pole pieces to provide a pair of beam focus lenses. One of the magnetic lenses is disposed on the inside of the beam path, whereas the other is disposed on the outside of the beam path to provide beam lateral focusing and defocusing lenses, respectively. The lenses are adjustable, preferably electromagnetically for controlling the beam spot size on the target crucible so that the evaporation characteristics can be optimized for a given beam power. In addition, the magnetic lenses are adjustable, preferably electromagnetically, for sweeping the position of the beam spot longitudinally and/or laterally of the crucible target. | 7 |
[0001] The instant invention relates to liquid sizing compositions comprising shading dyestuffs, derivatives of diaminostilbene, binders, protective polymers, and optionally divalent metal salts which can be used for the optical brightening of substrates, including substrates suitable for high quality ink jet printing.
BACKGROUND OF THE INVENTION
[0002] The problem of the decrease of the brightness while using shading dyes is a widely known problem.
[0003] Surprisingly, we have now discovered certain shading dyes which have a strongly positive effect on whiteness while having little or no effect on brightness, and which can be used in sizing compositions comprising optical brighteners, a protective polymer, binders, and optionally a divalent metal salt in order to enable the papermaker to reach high levels of whiteness and brightness.
[0004] Therefore, the goal of the present invention is to provide aqueous sizing compositions containing derivatives of diaminostilbene optical brightener, certain shading dyes, a protective polymer, binders, and optionally a divalent metal salt, which afford enhanced high whiteness levels while avoiding the disadvantages characterized by the use of shading dyes (loss of brightness) recognized as being state-of-the-art.
[0005] Therefore, the goal of the present invention is to provide a liquid sizing composition containing an acid dye and a derivative of diaminostilbene optical brightener affording a remarkably low loss in brightness.
[0006] Preferably the inventive process is characterized in that the liquid sizing compositions contain at least one protective polymer.
[0007] Preferably the inventive process is also characterized in that the liquid sizing compositions further contain at least one divalent metal salt.
[0008] The present invention further provides a process for surface tinting characterized in that an aqueous sizing composition containing at least one acid dye and at least one optical brightener is used.
DESCRIPTION OF THE INVENTION
[0009] The present invention therefore provides aqueous sizing compositions for optical brightening of substrates, preferably paper, comprising
(a) 0.0001 to 0.005% by weight of an acid dye of formula (1)
[0000]
wherein
R1 signifies H, methyl or ethyl,
R2 signifies paramethoxyphenyl, methyl or ethyl,
M signifies an alkali metal kation
(b) between 0.000002 to 0.0027% by weight of at least one protective polymer selected from
(i) a polyvinyl alcohol or a carboxylic acid containing polyvinyl alcohol; (ii) a homopolymer of acrylamide, acrylic acid or methacrylic acid; (iii) a copolymer of acrylic acid or methacrylic acid with acrylamide or methacrylamide. (iv) a polyethylene glycol;
(c) between 0.01 and 2% by weight of at least one optical brightener of formula (2);
[0000]
in which
the anionic charge on the brightener is balanced by a cationic charge composed of one or more identical or different cations selected from the group consisting of hydrogen, an alkali metal cation, alkaline earth metal, ammonium, ammonium which is mono-, di- or trisubstituted by a C1-C4 linear or branched alkyl radical, ammonium which is mono-, di- or trisubstituted by a C1-C4 linear or branched hydroxyalkyl radical, or mixtures of said compounds,
R 3 and R 3′ may be the same or different, and each is hydrogen, C1-C4 linear or branched alkyl, C2-C4 linear or branched hydroxyalkyl, CH 2 CO 2 − , CH 2 CH 2 CONH 2 or CH 2 CH 2 CN,
R 4 and R 4′ may be the same or different, and each is C1-C4 linear or branched alkyl, C2-C4 linear or branched hydroxyalkyl, CH 2 CO 2 − , CH(CO 2 − )CH 2 CO 2 − , CH(CO 2 − )CH 2 CH 2 CO 2 − , CH 2 CH 2 SO 3 − , benzyl, or
R 3 and R 4 and/or R 3′ and R 4′ , together with the neighboring nitrogen atom signify a morpholine ring and
p is 0, 1 or 2.
(d) between 1 and 30% by weight of at least one binder;
(e) optionally, between 0.1 and 10% by weight of at least one divalent metal salt;
(f) optionally a biozide and
(g) the remainder up to 100% by weight water.
[0031] This composition comprising the components (a) and (b) and (c) and (d) and (e) and (f) and (g) is preferably used to size paper in the size press. Therefore the composition comprising the components (a) and (b) and (c) and (d) and (e) and (f) and (g) is an aqueous sizing composition used in the production of coated paper.
[0032] In optical brighteners for which p is 1, the SO 3 − group is preferably in the 4-position of the phenyl group.
[0033] In optical brighteners for which p is 2, the SO 3 − groups are preferably in the 2,5-positions of the phenyl group.
[0034] Preferred compounds of formula (2) are those in which the anionic charge on the brightener is balanced by a cationic charge composed of one or more identical or different cations selected from the group consisting of hydrogen, an alkali metal cation, alkaline earth metal, ammonium which is mono-, di- or trisubstituted by a C1-C4 linear or branched hydroxyalkyl radical, or mixtures of said compounds,
R 3 and R 3′ may be the same or different, and each is hydrogen, C1-C4 linear or branched alkyl, C2-C4 linear or branched hydroxyalkyl, CH 2 CO 2 − , CH 2 CH 2 CONH 2 or CH 2 CH 2 CN, R 4 and R 4′ may be the same or different, and each is C1-C4 linear or branched alkyl, C2-C4 linear or branched hydroxyalkyl, CH 2 CO 2 − , CH(CO 2 − )CH 2 CO 2 − or CH(CO 2 − )CH 2 CH 2 CO 2 − and p is 0, 1 or 2.
[0038] More preferred compounds of formula (2) are those in which
the anionic charge on the brightener is balanced by a cationic charge composed of one or more identical or different cations selected from the group consisting of Li, Na, K, Ca, Mg, ammonium which is mono-, di- or trisubstituted by a C1-C4 linear or branched hydroxyalkyl radical, or mixtures of said compounds,
R 3 and R 3′ may be the same or different, and each is hydrogen, methyl, ethyl, α-methylpropyl, β-methylpropyl, β-hydroxyethyl, β-hydroxypropyl, CH 2 CO 2 − , CH 2 CH 2 CONH 2 or CH 2 CH 2 CN, R 4 and R 4′ may be the same or different, and each is methyl, ethyl, α-methylpropyl, β-methylpropyl, 3-hydroxyethyl, β-hydroxypropyl, CH 2 CO 2 − or
CH(CO 2 − )CH 2 CO 2 − , and
p is 0, 1 or 2.
[0044] Especially preferred compounds of formula (2) are those in which
the anionic charge on the brightener is balanced by a cationic charge composed of one or more identical or different cations selected from the group consisting of Na, K and triethanolamine or mixtures of said compounds,
R 3 and R 3′ may be the same or different, and each is hydrogen, ethyl, β-hydroxyethyl, β-hydroxypropyl, CH 2 CO 2 − , or CH 2 CH 2 CN, R 4 and R 4′ may be the same or different, and each is ethyl, β-hydroxyethyl, β-hydroxypropyl, CH 2 CO 2 − or CH(CO 2 − )CH 2 CO 2 − , and p is 2.
[0049] The binder is selected from the group consisting of native starch, enzymatically modified starch and chemically modified starch. Modified starches are preferably oxidized starch, hydroxyethylated starch or acetylated starch. The native starch is preferably an anionic starch, a cationic starch, or an amphoteric starch. While the starch source may be any, preferably the starch sources are corn, wheat, potato, rice, tapioca or sago.
[0050] The concentration of binder in the sizing composition may be between 1 and 30% by weight, preferably between 2 and 20% by weight, most preferably between 5 and 15% by weight.
[0051] Preferred divalent metal salts are selected from the group consisting of calcium chloride, magnesium chloride, calcium bromide, magnesium bromide, calcium iodide, magnesium iodide, calcium nitrate, magnesium nitrate, calcium formate, magnesium formate, calcium acetate, magnesium acetate, calcium citrate, magnesium citrate, calcium gluconate, magnesium gluconate, calcium ascorbate, magnesium ascorbate, calcium sulfite, magnesium sulfite, calcium bisulfite, magnesium bisulfite, calcium dithionite, magnesium dithionite, calcium sulphate, magnesium sulphate, calcium thiosulphate, magnesium thiosulphate or mixtures of said compounds.
[0052] More preferred divalent metal salts are selected from the group consisting of calcium chloride, magnesium chloride, calcium bromide, magnesium bromide, calcium sulphate, magnesium sulphate, calcium thiosulphate or magnesium thiosulphate or mixtures of said compounds.
[0053] Especially preferred divalent metal salts are selected from the group consisting of calcium chloride or magnesium chloride or mixtures of said compounds.
[0054] When the sizing composition contains a divalent metal salt, the concentration of divalent metal salt in the sizing composition may be between 1 and 100 g/l, preferably between 2 and 75 g/l, most preferably between 5 and 50 g/l.
[0055] When the divalent metal salt is a mixture of one or more calcium salts and one or more magnesium salts, the amount of calcium salts may be in the range of 0.1 to 99.9%.
[0056] The polyethylene glycol which may be employed as component (b) has an average molecular weight in the range of 100 to 8000, preferably in the range of 200 to 6000, most preferably in the range of 300 to 4500. When used as component (b), the content in the dyestuff solution may be between 0.1 and 10%, preferably between 0.1 and 7%, most preferably between 0.4 and 6%.
[0057] The polyvinyl alcohol which may be employed as component (b) has a degree of hydrolysis greater than or equal to 60% and a Brookfield viscosity of between 2 and 40 mPa·s for a 4% aqueous solution at 20° C. Preferably the degree of hydrolysis is between 69% and 95%, and the Brookfield viscosity is between 2 and 20 mPa·s (4% aqueous solution at 20° C.). Most preferably, the degree of hydrolysis is between 69% and 90%, and the Brookfield viscosity is between 2 and 20 mPa·s (4% aqueous solution at 20° C.). When used as component (b), the content in the dyestuff solution may be between 0.1 and 6%, preferably between 0.1 and 5%, most preferably between 0.2 and 5%.
[0058] The carboxylic acid containing polyvinyl alcohol which may be employed as component (b) has a degree of hydrolysis greater than or equal to 60% and a Brookfield viscosity of between 2 and 40 mPa·s for a 4% aqueous solution at 20° C. Preferably the degree of hydrolysis is between 70% and 95%, and the Brookfield viscosity is between 2 and 35 mPa·s (4% aqueous solution at 20° C.). Most preferably, the degree of hydrolysis is between 70% and 90%, and the Brookfield viscosity is between 2 and 30 mPa·s (4% aqueous solution at 20° C.).
[0059] When used as component (b), the content in the dyestuff solution may be between 0.1 and 6%, preferably between 0.1 and 5%, most preferably between 0.2 and 5%.
[0060] The polymer of acrylamide which may be employed as component (b) has a Brookfield viscosity of between 100 and 40000 mPa·s for a 0.5-20% aqueous solution at 20-25° C. Preferably the viscosity is between 100 and 30000 mPa·s (0.5-20% aqueous solution at 20-25° C.). Most preferably, the viscosity is between 100 and 10000 mPa·s (0.5-20% aqueous solution at 20-25° C.). When used as component (b), the content in the dyestuff solution may be between 0.05 and 3%, preferably between 0.05 and 2%, most preferably between 0.05 and 1.5%.
[0061] The polymer of acrylic acid or methacrylic acid which may be employed as component (b) has a Brookfield viscosity of between 100 and 40000 mPa·s for a 7-8% aqueous solution at 20° C. The polymer can be optionally used in its partial or full salt form. The preferred salt is Na, K, Ca, Mg, ammonium or ammonium which is mono-, di- or tri-substituted by a linear or branched alkyl or hydroxyalkyl radical. Preferably the viscosity is between 1000 and 30000 mPa·s (7-8% aqueous solution at 20° C.). Most preferably, the viscosity is between 5000 and 20000 mPa·s (7-8% aqueous solution at 20° C.). When used as component (b), the content in the dyestuff solution may be between 0.1 and 6%, preferably between 0.1 and 5%, most preferably between 0.2 and 5%.
[0062] The copolymer of acrylic acid and acrylamide which may be employed as component (b) has a Brookfield viscosity of between 1 and 100 mPa·s for a 0.1 aqueous solution at 20° C. The copolymer can be either a block or a cross-linked copolymer. The copolymer can be optionally used in its partial or full salt form. The preferred salt is Na, K, Ca, Mg, ammonium or ammonium which is mono-, di- or tri-substituted by a linear or branched alkyl or hydroxyalkyl radical. Preferably the viscosity is between 1 and 80 mPa·s (0.1% aqueous solution at 20° C.). Most preferably, the viscosity is between 1 and 50 mPa·s (0.1% aqueous solution at 20° C.). When used as component (b), the content in the dyestuff solution may be between 0.1 and 6%, preferably between 0.1 and 5%, most preferably between 0.2 and 5%.
[0063] The copolymer of methacrylic acid and methacrylamide which may be employed as component (b) has a Brookfield viscosity of between 1 and 100000 mPa·s for an 8% aqueous solution at 20° C. The copolymer can be either a block or a cross-linked copolymer. The copolymer can be optionally used in its partial or full salt form. The preferred salt is Na, K, Ca, Mg, ammonium or ammonium which is mono-, di- or tri-substituted by a linear or branched alkyl or hydroxyalkyl radical. Preferably the viscosity is between 10000 and 80000 mPa·s (8% aqueous solution at 20° C.). Most preferably, the viscosity is between 40000 and 50000 mPa·s (8% aqueous solution at 20° C.). When used as component (b), the content in the dyestuff solution may be between 0.1 and 6%, preferably between 0.1 and 5%, most preferably between 0.2 and 4%.
[0064] The pH value of the sizing composition is typically in the range of 5-13, preferably 6-11.
[0065] The sizing composition may additionally contain by-products formed during the preparation of the optical brightener as well as other conventional paper additives. Examples of such additives are antifreezes, biocides, defoamers, wax emulsions, inorganic salts, solubilizing aids, preservatives, complexing agents, thickeners, surface sizing agents, cross-linkers, pigments, special resins etc.
[0066] The sizing composition is prepared by adding the optical brightener, the shading dye, the protective polymer and optionally the divalent metal salt to a preformed aqueous solution of the binder at a temperature between 20° C. and 90° C.
[0067] The sizing composition is prepared by adding the solution of the shading dye containing the protective polymer, the optical brightener and optionally the divalent metal salt to a preformed aqueous solution of the binder at a temperature between 20° C. and 90° C.
[0068] Alternatively the single components may be added individually and then mixed. However, in many cases it might be favorable to produce stock solutions from the Acid Dye and the protective polymer and mix this stock solution with the further ingredients.
[0069] The sizing composition may be applied to the surface of a paper substrate by any surface treatment method known in the art. Examples of application methods include size-press applications, calendar size application, tub sizing, coating applications and spraying applications. (See, for example, pages 283-286 in Handbook for Pulp & Paper Technologists by G. A. Smook, 2 nd Edition Angus Wilde Publications, 1992 and US 2007/0277950.) The preferred method of application is at the size-press such as puddle size press. A preformed sheet of paper is passed through a two-roll nip which is flooded with the sizing composition.
[0070] The paper absorbs some of the composition, the remainder being removed in the nip.
[0071] The paper substrate contains a web of cellulose fibres which may be sourced from any fibrous plant. Preferably the cellulose fibres are sourced from hardwood and/or softwood. The fibres may be either virgin fibres or recycled fibres, or any combination of virgin and recycled fibres.
[0072] The cellulose fibres contained in the paper substrate may be modified by physical and/or chemical methods as described, for example, in Chapters 13 and 15 respectively in Handbook for Pulp & Paper Technologists by G. A. Smook, 2 nd Edition Angus Wilde Publications, 1992. One example of a chemical modification of the cellulose fibre is the addition of an optical brightener as described, for example, in EP 884,312, EP 899,373, WO 02/055646, WO 2006/061399 and WO 2007/017336.
[0073] One example of an especially preferred optical brightener of formula (2) is described by formula (3). Preparative methods for synthesizing optical brightener of formula (3) are well-known.
[0000]
EXAMPLES
[0074] The following examples shall demonstrate the instant invention in more details. In the present application, if not indicated otherwise, “parts” means “parts by weight”, “%” means “% by weight” and viscosities are measured using a Brookfield viscosimeter at 20° C., using spindle No 18, according to DIN 53214. The viscosities of the polyvinyl alcohols are measured by a Höppler viscosimeter according to DIN 53015.
[0075] To the dyestuff solutions can be added optionally a biocide for example Proxel™ GXL (Proxel is a trade mark of Zeneca AG Products, Inc. and comprises 1,2-benzisothiazolin-3-one (CAS No.: 2634-33-5)).
[0076] The order in which the single parts of the following solutions or sizing compositions are added are outlined below but are not limited to those mentioned. However, the order of addition is generally not critical.
Preparative Example 1
[0077] Into 567 g warm water of 50-60° C. are added under stirring within 60 minutes 73.4 g Acid Violet 49 (95% material). Agitation is continued for a further hour at 60° C. while a solution forms. The dyestuff solution is then clarified by the use of a filtering aid. Afterwards 2.8 g of a polyvinyl alcohol, having a degree of hydrolysis of 69.5-72.5% and a Brookfield viscosity of 5-5.8 mPa·s, are dissolved in approx. 104 ml of deionised water of 80-90° C. by stirring one hour at this temperature. After cooling this pale yellow solution to room temperature it is poured into the dyestuff solution. Further deionised water is added to receive 711.5 g dyestuff solution. After cooling to room temperature the solution remains stable and the pH is in the range of 6.5-7.5.
[0078] A sample of the solution thus obtained was stable even after two weeks of storage at 0° C. and thawing in that it neither separated nor developed streaks. Similarly, the sample stored for two weeks at 50° C. and cooled down to room temperature was observed neither to separate nor to develop streaks.
Preparative Example 2
[0079] A dyestuff solution is obtained following the same procedure as in example 1 with the sole differences that 14.2 g of a polyvinyl alcohol are used having a degree of hydrolysis of 69.5-72.5% and a Brookfield viscosity of 5-5.8 mPa·s. The pH of the solution is in the range of 6.5-7.0.
Preparative Example 3
[0080] A dyestuff solution is obtained following the same procedure as in example 1 with the sole differences that 2.8 g of a polyvinyl alcohol are used having a degree of hydrolysis of approx. 88% and a Brookfield viscosity of 7.0-9.0 mPa·s. The pH of the solution is in the range of 6.5-7.5.
Preparative Example 4
[0081] Into 567 g warm water of 50-60° C. are added under stirring within 60 minutes 73.4 g Acid Violet 49 (95% material). Agitation is continued for further 30 minutes at 60° C. while a solution forms. Afterwards 3.6 g of a polyvinyl alcohol are added having a degree of hydrolysis of approx. 85% and a Brookfield viscosity of 3.4-4.0 mPa·s. The mixture is stirred for another 30 minutes at 60° C. and diluted with deionised water to receive 711.5 g solution. After cooling to room temperature the solution remains stable and the pH is in the range of 6.5-7.5.
Preparative Example 5
[0082] A dyestuff solution is obtained following the same procedure as in example 1 with the sole differences that 3.6 g of a polyacrylamide in form of 109.1 g of a 3.3% aqueous solution are used. A clear 3.3% aqueous solution of this polyacrylamide has a Brookfield viscosity of 105 mPa·s at 20° C.
[0083] The pH of the dyestuff solution is in the range of 6.5-7.0.
Preparative Example 6
[0084] A dyestuff solution is obtained following the same procedure as in example 4 with the sole differences that 3.6 g of a polyacrylamide in form of 18 g of a 20% aqueous solution are used. The clear 20% aqueous solution of this polyacrylamide has a Brookfield viscosity of 500-1000 mPa·s at 25° C. The pH of the dyestuff solution is in the range of 6.5-7.0.
Preparative Example 7
[0085] A dyestuff solution is obtained following the same procedure as in example 4 with the sole differences that 3.6 g of a polyacrylamide are used. The clear 0.5% aqueous solution of this polyacrylamide has a Brookfield viscosity of 120 mPa·s at 25° C.
[0086] The pH of the dyestuff solution is in the range of 6.0-6.5.
Preparative Example 8
[0087] A dyestuff solution is obtained following the same procedure as in example 4 with the sole differences that 3.6 g of a polyacrylamide are used. The clear 0.5% aqueous solution of this polyacrylamide has a Brookfield viscosity of approx. 240 mPa·s at 25° C.
[0088] The pH of the dyestuff solution is in the range of 6.0-6.5.
Preparative Example 9
[0089] A dyestuff solution is obtained following the same procedure as in example 4 with the sole differences that 3.6 g of a polyacrylamide are used and dissolved at 80° C. The clear 10% aqueous solution of this polyacrylamide has a Brookfield viscosity of approx. 320 mPa·s at 25° C.
[0090] The pH of the dyestuff solution is approx. 6.5.
Preparative Example 10
[0091] Into 567 g warm water of 50-60° C. are added under stirring within 60 minutes 36.7 g Acid Violet 49 (95% material). Agitation is continued for a further hour at 60° C. while a solution forms. The dyestuff solution is then clarified by the use of a filtering aid. Afterwards 3.6 g of a polyacrylamide in form of 109.1 g of a 3.3% aqueous solution are dosed in. Further deionised water is added to receive 711.5 g dyestuff solution. After cooling down to room temperature the solution remains stable and the pH is in the range of 6.0-6.5. A clear 3.3% aqueous solution of this polyacrylamide has a Brookfield viscosity of 105 mPa·s at 20° C.
Preparative Example 11
[0092] A dyestuff solution is obtained following the same procedure as in example 10 with the sole differences that 35.6 g of a polyethylene glycol having an average molecular weight of 1500 are used.
[0093] The pH of the dyestuff solution is approx. 6.0.
Preparative Example 12
[0094] A dyestuff solution is obtained following the same procedure as in example 10 with the sole differences that 3.6 g of a poly(acrylamide-co-acrylic acid) having a Brookfield viscosity between 2 and 3 mPa·s for a 0.1% aqueous solution at 20° C. are used.
[0095] The pH of the dyestuff solution is in the range of 6.0-6.5.
Preparative Example 13
[0096] A dyestuff solution is obtained following the same procedure as in example 10 with the sole differences that 17.8 g of a carboxylic acid containing polyvinyl alcohol having a degree of hydrolysis between 85% and 90% and a Brookfield viscosity between 20 and 30 mPa·s for a 4% aqueous solution at 20° C. are used.
[0097] The pH of the dyestuff solution is approx. 6.0.
Preparative Example 14
[0098] Preparation of poly(methacrylamide-co-methacrylic acid): 0.15 parts of radical initiator Vazo68 are mixed with 43.25 parts of methacrylic acid, 43.18 parts of methacrylamide and 1000 parts of demineralized water. The mixture is stirred and heated under nitrogen to 74-76° C. over a period of 1 hour. After 10 minutes at 74-76° C., stirring is stopped and the mixture is left 16 hours at 74-76° C. 45.6 parts of aqueous sodium hydroxide (33%) are added, stirring is re-started and the temperature is allowed to fall to room temperature. The pH of the final product is approx. 7.0-8.0 and the viscosity is approx. 40000-50000 mPa·s at 20° C.
[0099] The aqueous solution so-formed (1132 parts) contains approx. 90 parts of poly(methacrylamide-co-methacrylic acid) as its sodium salt.
Preparative Example 15
[0100] A dyestuff solution is obtained following the same procedure as in example 10 with the sole differences that 7.1 g of the poly(methacrylamide-co-methacrylic acid) in form 88.9 g of an aqueous solution prepared according to preparative example 14. The pH of the dyestuff solution is in the range of 6.5-7.0.
Preparative Example 16
[0101] Into 567 g warm water of 50-60° C. are added under stirring within 60 minutes 73.4 g Acid Violet 17 (95% material). Agitation is continued for further 30 minutes at 60° C. while a solution forms. The dyestuff solution is then clarified by the use of a filtering aid. Afterwards 2.8 g of a polyvinyl alcohol are added having a degree of hydrolysis of 69.5-72.5% and a Brookfield viscosity of 5-5.8 mPa·s. The mixture is heated up to 80° C., stirred for another 60 minutes at this temperature and diluted with deionised water to receive 711.5 g solution. After cooling to room temperature the solution remains stable and the pH is in the range of 6.5-7.5.
Preparative Example 17
[0102] A dyestuff solution is obtained following the same procedure as in example 16 with the sole differences that 14.2 g of a polyvinyl alcohol are used having a degree of hydrolysis of 69.5-72.5% and a Brookfield viscosity of 5-5.8 mPa·s. The pH of the solution is in the range of 6.5-7.0.
Preparative Example 18
[0103] A dyestuff solution is obtained following the same procedure as in example 16 with the sole differences that 2.8 g of a polyvinyl alcohol are used having a degree of hydrolysis of approx. 88% and a Brookfield viscosity of 7.0-9.0 mPa·s. The pH of the solution is in the range of 6.5-7.5.
Preparative Example 19
[0104] A dyestuff solution is obtained following the same procedure as in example 16 with the sole differences that 3.6 g of a polyacrylamide are used. The clear 0.5% aqueous solution of this polyacrylamide has a Brookfield viscosity of approx. 240 mPa·s at 25° C.
[0105] The pH of the dyestuff solution is in the range of 6.0-6.5.
Preparative Example 20
[0106] A dyestuff solution is obtained following the same procedure as in example 16 with the sole differences that 3.6 g of a polyacrylamide are used and dissolved at 80° C. The clear 10% aqueous solution of this polyacrylamide has a Brookfield viscosity of 320 mPa·s at 25° C.
[0107] The pH of the dyestuff solution is approx. 6.5.
Comparative example 1
[0108] A dyestuff solution is obtained following the same procedure as in Example 1 with the sole differences that no protective polymer is added. The pH of the dyestuff solution is approx. 7.0.
Comparative Example 2
[0109] A dyestuff solution is obtained following the same procedure as in Example 10 with the sole differences that no protective polymer is added. The pH of the dyestuff solution is approx. 7.0.
Comparative Example 3
[0110] A dyestuff solution is obtained following the same procedure as in Example 16 with the sole differences that no protective polymer is added. The pH of the dyestuff solution is approx. 7.0.
Application Example 1 with CaCl 2
[0111] The dyestuff solution prepared according to preparative example 4 is diluted to a concentration of 0.01%.
[0112] A sizing composition is prepared by adding the diluted dyestuff solution at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of calcium chloride (35 g/l), optical brightener of formula 3 (40 g/l) of a 18.2% stock solution and an anionic starch (100 g/l) (Penford Starch 260) at 60° C. The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0113] The dried paper is allowed to condition, and then measured for CIE whiteness and brightness on a calibrated Auto Elrepho spectrophotometer. The results are shown in Table 1-2.
[0114] The light fastness is measured on Minolta CM-3700d spectrophotometer and the results are shown in Table 3.
Comparative Application Example 1 with Cacl 2
[0115] The dyestuff solution prepared according to comparative example 2 is diluted to a concentration of 0.01%.
[0116] A sizing composition is prepared by adding the diluted dyestuff solution at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of calcium chloride (35 g/l), optical brightener of formula 3 (40 g/l) of a 18.2% stock solution and an anionic starch (100 g/l) (Penford Starch 260) at 60° C. The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0117] The dried paper is allowed to condition, and then measured for CIE whiteness and brightness on a calibrated Auto Elrepho spectrophotometer. The results are shown in Table 1-2.
[0118] The light fastness is measured on Minolta CM-3700d spectrophotometer and the results are shown in Table 3 and 4.
Application Example 2 with CaCl 2
[0119] The dyestuff solutions prepared according to preparative examples 10-13 and 15 are diluted to a concentration of 0.01%.
[0120] Sizing compositions are prepared by adding this diluted aqueous solutions at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of anionic starch (100 g/l) (Penford Starch 260) at 60° C. containing calcium chloride (35 g/l) and an optical brightener of formula 3 (40 g/l) of a 18.2% stock solution. The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0121] The dried paper is allowed to condition, and then the light fastness is measured on Minolta CM-3700d spectrophotometer and the results are shown in Table 4.
Application Example 3 with Cacl 2
[0122] The dyestuff solutions prepared according to preparative examples 1-3 and 5-9 and comparative example 1 are diluted to a concentration of 0.01%.
[0123] Sizing compositions are prepared by adding this diluted aqueous solutions at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of calcium chloride (35 g/l), optical brightener of formula 3 (40 g/l) of a 18.2% stock solution and an anionic starch (100 g/l) (Penford Starch 260) at 60° C. The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0124] The dried paper is allowed to condition, and then measured for CIE whiteness and brightness on a calibrated Auto Elrepho spectrophotometer. The results are shown in Table 5-6.
[0125] The light fastness is measured on Minolta CM-3700d spectrophotometer and the results are shown in Table 7.
Application Example 4 without CaCl 2
[0126] The dyestuff solutions prepared according to preparative examples 2, 7, 9 and comparative example 1 are diluted to a concentration of 0.01%.
[0127] Sizing compositions are prepared by adding this diluted aqueous solutions at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of anionic starch (100 g/l) (Penford Starch 260) at 60° C. containing an optical brightener of formula 3 (40 g/l) of a 18.2% stock solution. The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0128] The dried paper is allowed to condition and the light fastness is measured on Minolta CM-3700d spectrophotometer. The results are shown in Table 8.
Application Example 5 with CaCl 2
[0129] The dyestuff solutions prepared according to preparative examples 16-20 and comparative example 3 are diluted to a concentration of 0.01%.
[0130] The sizing composition and the application on paper are made according to application example 2. The dried paper is allowed to condition, and then measured for CIE whiteness and brightness on a calibrated Auto Elrepho spectrophotometer. The results are shown in Table 9-10.
Application Example 6 without CaCl 2
[0131] The dyestuff solutions prepared according to preparative examples 17, 18 and comparative example 3 are diluted to a concentration of 0.01%.
[0132] Sizing compositions are prepared by adding this diluted aqueous solutions at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of anionic starch (100 g/l) (Penford Starch 260) at 60° C. containing an optical brightener of formula 3 (40 g/l) of a 18.2% stock solution. The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0133] The dried paper is allowed to condition, and then measured for the light fastness on Minolta CM-3700d spectrophotometer and the results are shown in Table 11.
Application Example 7 with CaCl 2 , UV OFF
[0134] The dyestuff solutions prepared according to preparative examples 16-20 and comparative example 3 are diluted to a concentration of 0.01%.
[0135] Sizing compositions are prepared by adding the diluted dyestuff solutions at a range of concentrations from 0 to 0.03 g/l to a stirred, aqueous solution of anionic starch (100 g/l) (Penford Starch 260) at 60° C. containing calcium chloride (35 g/l).
[0136] The sizing solution is allowed to cool, then poured between the moving rollers of a laboratory size-press and applied to a commercial 75 g/m 2 AKD (alkyl ketene dimer) sized, bleached paper base sheet. The treated paper is dried for 5 minutes at 70° C. in a flat bed drier.
[0137] The dried paper is allowed to condition, and then measured for CIE whiteness and brightness on a calibrated Auto Elrepho spectrophotometer. The results are shown in Table 12-13.
[0000]
TABLE 1
Development of whiteness with increasing amounts of dyestuff in the
presence of CaCl 2
Dye [g/l]
0
0.0025
0.005
0.01
0.02
0.03
Direct Violet
132.43
132.52
132.89
133.43
135.88
136.62
35
Prep.
132.43
134.51
135.96
138.29
141.73
145.54
example 4
Comp.
132.43
134.16
136.34
138
141.46
—
example 2
[0138] The results clearly show that the instant invention (Acid Violet 49 solutions, with and without polymer) provides a higher level of whiteness than Direct Violet 35 representing the state-of-the-art (Table 1).
[0000]
TABLE 2
Development of brightness with increasing amounts of dyestuff in the
presence of CaCl 2
Dye [g/l]
0
0.0025
0.005
0.01
0.02
0.03
Direct Violet
105.25
103.99
103.82
103.51
102.74
101.56
35
Prep.
105.25
105.37
105.33
105.31
104.81
104.53
example 4
Comp.
105.25
105.34
105.43
105.11
104.88
—
example 2
[0139] The results clearly show that the instant invention leads to a remarkably lower loss of brightness than Direct Violet 35 representing the state-of-the-art. At the highest addition level of shading dye (Prep. ex. 4) the loss in brightness is only 0.7% compared with 3.5% when using Direct Violet 35 (Table 2).
[0000]
TABLE 3
Lightfastness with increasing time of illumination in the presence of CaCl 2
hours of exposure
0
0.5
1
2
5
10
Direct Violet 35
0
−4.6
−6.9
−8.8
−12.3
−14
Prep. example 4
0
−4.4
−6.8
−8.4
−12.1
−11.9
Comp. example 2
0
−9.6
−11.5
−14.2
−16.8
−18.7
[0140] Paper shaded in the size press with an Acid Violet 49 solution containing the poly vinyl alcohol described in the Preparative example 4 leads to a better light fastness than the Comparative example 2 where no protective polymer is used (Table 3).
[0000]
TABLE 4
Lightfastness with increasing time of illumination in the presence of CaCl 2
hours of exposure
0
0.5
1
2
5
10
Direct Violet 35
0
−0.6
−1.7
−4.8
−8.7
−10.6
Prep. example 11
0
−2
−4.6
−8
−10.6
−12.2
Prep. example 10
0
−1.3
−3.6
−7.1
−9.5
−11.6
Prep. example 12
0
−3.3
−7.1
−9.2
−13.2
−16.7
Prep. example13
0
−4
−5.5
−8.7
−13.5
−17.5
Prep. example 15
0
−5.4
−7.3
−10.4
−14
−17.7
Comp. example 2
0
−6.1
−8.9
−13.5
−15
−18.3
[0141] Paper shaded in the size press with Acid Violet 49 solutions containing different protective polymers synthesized according to the Preparative examples 10-13 and 15 lead to a better light fastness than the Comparative example 2 without a protective polymer (Table 4). Best results are obtained with polyethylene glycol having an average molecular weight of 1500 (Prep. example 11) and the polyacrylamide described in the Prep. example 10.
[0000]
TABLE 5
AV 49; Development of whiteness with increasing amounts of dyestuff in
the presence of CaCl 2
Dye [g/l]
0
0.005
0.01
0.015
0.02
0.03
DV 35
133.6
134.97
135.18
136.1
137.1
138.95
Prep. ex. 1
133.6
135.4
137.57
139.03
140.4
144.2
Prep. ex. 2
133.6
135.19
138.17
139.81
141.09
145.65
Prep. ex. 3
133.6
135.5
137.34
139.54
141.2
146.66
Prep. ex. 5
133.6
136.39
138.58
140.01
142.44
146.01
Prep. ex. 6
133.6
136.59
138.83
140.04
141.13
145.69
Prep. ex. 7
133.6
136.34
138.04
139.37
140.75
144.76
Prep. ex. 8
133.6
136.46
138.9
140.03
142.4
146.31
Prep. ex. 9
133.6
135.83
137.35
139.66
141.77
145.19
Comp. ex. 1
133.6
135.46
137.2
139.7
142.4
144.95
[0142] With Acid Violet 49 solutions (with and without polymer) the whiteness degree is built up better than with Direct Violet 35 (Table 5). Best results are obtained with polyvinylalcohol described in Prep. example 3 and the polyacrylamides described in Prep. examples 8 and 5.
[0000]
TABLE 6
AV 49; Development of brightness with increasing amounts of dyestuff in
the presence of CaCl 2
Dye [g/l]
0
0.005
0.01
0.015
0.02
0.03
DV 35
105.198
104.829
104.15
103.747
103.176
102.564
Prep. ex. 1
105.198
105.045
105.118
104.791
104.608
104.662
Prep. ex. 2
105.198
105.153
105.104
104.992
104.875
104.75
Prep. ex. 3
105.198
105.1
104.977
104.937
104.861
104.9
Prep. ex. 5
105.198
105.372
105.364
105.17
105.18
105.07
Prep. ex. 6
105.198
105.364
105.295
104.846
104.822
104.884
Prep. ex. 7
105.198
105.466
105.184
104.984
104.74
104.755
Prep. ex. 8
105.198
105.48
105.329
105.18
105.068
104.87
Prep. ex. 9
105.198
105.203
105.103
105.03
105.001
104.814
Comp. ex. 1
105.198
105.083
104.925
104.943
104.945
104.494
[0143] The loss of brightness at the highest addition level of Acid Violet 49 solutions is only in the range of 0.12% to 0.7% (Prep. ex. 5, Comp. ex. 1), in contrast to Direct Violet 35 showing a remarkable drop in brightness (Table 6). Best results are obtained with polyacrylamides described in Prep. examples 5, 8 and 9.
[0000]
TABLE 7
AV 49; Lightfastness with increasing time of illumination in the presence
of CaCl 2
hours of exposure
0
0.5
1
2
5
10
DV 35
0
−5.2
−8
−9.6
−15.8
−18.7
Prep. ex. 2
0
−3.7
−6.9
−8.5
−13.5
−17.7
Prep. ex. 6
0
−4.8
−6.2
−7.9
−14.3
−18.3
Prep. ex. 9
0
−3.8
−5.6
−7.7
−13.6
−15.6
Comp. ex. 1
0
−5.3
−7.9
−9.6
−14
−18.6
[0144] Paper shaded in the size press with Acid Violet 49 solutions containing different protective polymers synthesized according to the Preparative examples 2, 6 and 9 lead to similar or better light fastness than the Comparative example 1 without a protective polymer (Table 7). Best result is obtained with polyacrylamide described in Prep. example 9.
[0000]
TABLE 8
AV 49; Lightfastness with increasing time of illumination without CaCl 2
hours of exposure
0
0.5
1
2
5
10
DV 35
0
−4
−6.4
−9.5
−11.8
−15.9
Prep. ex. 2
0
−3.9
−6.2
−9.1
−12.4
−19.2
Prep. ex. 7
0
−1.7
−5
−7.7
−11.2
−17.6
Prep. ex. 9
0
−2
−5.2
−6.5
−9.9
−16.4
Comp. ex. 1
0
−5.3
−8
−10.8
−14.2
−19.5
[0145] Without CaCl 2 in the sizing composition the best light fastness is obtained with the polyacrylamide described in Prep. examples 9 (Table 8).
[0000]
TABLE 9
AV 17; Development of whiteness with increasing amounts of dyestuff in
the presence of CaCl 2
Dye [g/l]
0
0.005
0.01
0.015
0.02
0.03
DV 35
135.55
136.48
138.21
140.4
141.3
143.27
Prep. ex.
135.55
139.41
141.3
144.88
146.88
149.2
16
Prep. ex.
135.55
139.54
141.92
143.54
145.93
149.14
17
Prep. ex.
135.55
140.5
142.02
144.19
146.55
150.1
18
Prep. ex.
135.55
139.97
142.57
144.36
146.15
149.95
19
Prep. ex.
135.55
140.43
141.38
144.21
145.79
149.88
20
Comp. ex. 3
135.55
138.99
141.39
144.3
146.31
150.04
[0146] With solutions of Acid Violet 17 (with and without polymer) the whiteness degree is built up better than with Direct Violet 35 (Table 9). The whiteness degrees are similar than those achieved with Acid Violet 49 (Table 5).
[0000]
TABLE 10
AV 17; Development of brightness with increasing amounts of dyestuff in
the presence of CaCl 2
Dye [g/l]
0
0.005
0.01
0.015
0.02
0.03
DV 35
105.809
105.173
105.049
104.788
104.315
103.633
Prep. ex.
105.809
106.535
106.537
106.748
106.682
106.306
16
Prep. ex.
105.809
106.539
106.498
106.365
106.462
106.238
17
Prep. ex.
105.809
107.023
106.492
106.54
106.625
106.355
18
Prep. ex.
105.809
106.71
106.768
106.561
106.499
106.329
19
Prep. ex.
105.809
106.786
106.41
106.585
106.466
106.478
20
Comp. ex. 3
105.809
106.355
106.392
106.555
106.499
106.368
[0147] Even at highest addition level of Acid Violet 17 solutions (with and without polymer) the brightness is above the level of the base paper (without any dyestuff), in contrast to Direct Violet 35 showing a remarkable drop in brightness (Table 10). The results obtained with different polymers are very similar. The brightness degrees are similar than those obtained with Acid Violet 49 (Table 6).
[0000]
TABLE 11
AV 17; Lightfastness with increasing time of illumination without CaCl 2
hours of exposure
0
0.5
1
2
5
10
DV 35
0
−3.6
−4.3
−9.2
−12.4
−17
Prep. ex. 17
0
−3.2
−4.9
−9.5
−13.9
−18.9
Prep. ex. 18
0
−4.4
−6
−9.7
−11.2
−15.9
Comp. ex. 3
0
−4.3
−6.2
−10.8
−13.6
−18
[0148] The polyvinylalcohol described in the Prep. example 18 leads to a higher light fastness than it is obtained with the Comparative example 3 (Table 11).
[0000]
TABLE 12
AV17; Development of whiteness with increasing amounts of dyestuff in
the presence of CaCl 2 ; without OBA
Dye [g/l]
0
0.005
0.01
0.015
0.02
0.03
DV 35
80.7
82.23
84.63
86.83
88.24
91
Prep. ex.
80.7
83.86
85.92
88.13
90.26
93.67
16
Prep. ex.
80.7
83.73
86.03
88
89.84
93.63
17
Prep. ex.
80.7
83.98
85.99
88.17
90.28
94.29
18
Prep. ex.
80.7
83.85
85.89
88.47
90.21
94.18
19
Prep. ex.
80.7
83.88
85.87
88.2
90.03
93.78
20
Comp. ex. 3
80.7
83.77
86.06
88.37
90.3
94.1
[0149] Even without an optical brightener the whiteness degree is built up better than with Direct Violet 35 (Table 12).
[0000]
TABLE 13
AV 17; Development of brightness with increasing amounts of dyestuff in
the presence of CaCl 2 ; without OBA
Dye [g/l]
0
0.005
0.01
0.015
0.02
0.03
DV 35
85.203
84.974
84.955
84.843
84.63
84.393
Prep. ex.
85.203
85.618
85.582
85.522
85.522
85.484
16
Prep. ex.
85.203
85.587
85.561
85.535
85.499
85.457
17
Prep. ex.
85.203
85.631
85.579
85.565
85.529
85.445
18
Prep. ex.
85.203
85.626
85.566
85.554
85.521
85.425
19
Prep. ex.
85.203
85.595
85.569
85.56
85.48
85.502
20
Comp. ex. 3
85.203
85.626
85.63
85.61
85.512
85.436
[0150] When using AV 17 solutions even without an optical brightener the brightness is above the level of the base paper in contrast to Direct Violet 35 (Table 13). | The instant invention relates to liquid sizing compositions comprising shading dyestuffs, derivatives of diaminostibene, binders, protective polymers, and optionally divalent metal salts which can be used for the optical brightening of substrates, including substrates suitable for high quality ink jet printing. | 3 |
REFERENCE TO RELATED APPLICATION
This application claims priority of U.S. provisional application Serial No. 60/019,962, filed Jun. 17, 1996, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to medical instrumentation and, in particular, to apparatus and methods which support a wide variety of measurement, collection, communication, and analysis functions.
BACKGROUND OF THE INVENTION
There exists a need for comprehensive physiological monitoring in portable and remote settings. Current systems are generally large, costly, and inflexible, and although portable devices are now becoming available, they provide only limited, special-purpose capabilities. More specifically, existing medical instruments do not support multiple, programmable input channels which would allow any analog signal type (EEG, EMG, EKG, or higher-level signals) to be filtered, amplified, digitized, encapsulated, and routed through a complex digital network under programmed control, thereby offering a truly universal data core function.
At the same time, in the computer industry there has been a movement toward system interoperability through open systems protocols. This movement is being driven by TCP/IP, followed by X-windows (for transmission of windowed graphics), NFS (for file systems access), and new applications level protocols and file formats such as X.500, HTML, and SMTP. These protocols and file format standards have allowed interoperability between computers using different operating systems, hardware platforms, and applications suites. Within the Government and industry these data transfer protocols, mostly oriented towards transmission and/or sharing of images and documents, have substantially improved the usefulness of office and home computers. With respect to medical instrumentation, however, such support for multiple platforms or distributed, object-oriented collection and analysis architectures for multiple data types do not yet exist.
To review relevant patent literature, U.S. Pat. No. 4,838,275 describes a home medical surveillance system which is designed to serve multiple patients in their homes. The system suggests the sensing of multiple parameters for patient health assessment and which are sent to a central observation sight. The data transmission/reception methods described predate the widespread use of the modern, distributed Internet concepts, and instead rely on simple point-to-point data transfer without specific data-independent object-oriented encapsulation coding methods. Data interpretation is strictly manually performed by a human observer, with no means for automated signal interpretation, and there is no indication that the input channels for data are in any sense general purpose.
U.S. Pat. No. 5,228,450 describes apparatus for ambulatory physiological monitoring which includes compact portable computer controlled data acquisition of ECG signals, including buffering and display. The invention focuses on the collection of ECG data and does not describe how any other physiological signal might be acquired. Nor does the invention include a communications means or an architecture in support of propagation encapsulated object-oriented data.
U.S. Pat. No. 5,231,990 describes an applications-specific integrated circuit for physiological monitoring which supports multiple inputs to implement flexible multi-channel medical instrumentation. The signal processing and programmable gain functions described are consistent with ECG-type filtering and monitoring. However, the subject matter does not involve communications or network interoperation, data buffering, data encapsulation, or an architecture for routing, buffering, and analysis. While the invention does involve programmable functions, it does not describe how it could be applicable to all relevant medical signals (specifically EEG).
U.S. Pat. No. 5,331,549 describes a medical monitoring system which supports a plurality of vital signs measurements supplied on a continuous basis to a central data collection server, which in turn, provides various display functions. The invention does not indicate that the vital signs inputs are multiple function, that the central computer is networked to other systems so that data collection and viewing can occur anywhere in the network, or that data is in anyway encapsulated for object-oriented processing.
U.S. Pat. No. 5,375,604 describes a transportable modular patient monitor which supports the collection of data from a plurality of sensors. The system supports multiple types of data through attachable applications-specific pods which have the electrical characteristics necessary to match specific low-gain sensor input signals (EKG, blood pressure, pulse oximetry, etc., but not EEG). The system transfers data to and from the patient and display systems through a local area network connection. Key innovations appear to be modular signal specific data collection pods, detached portable monitoring system with docking stations, and a means for providing continuous monitoring. The patent does not describe input channels which, under programmed control, are configurable to all medical sensor inputs, nor does it describe a local and wide area network data collection, encapsulation, routing, or analysis.
U.S. Pat. No. 5,458,123 measures vital signs sensors and uses a multiple antenna-based radio direction finding system for tracking patient location. The system is restricted to low-gain physiological signals such as EKG, temperature, heart rate, etc.
U.S. Pat. No. 5,438,607 describes a programmable monitoring system and method for use in the home, medical ward, office, or other localized area. A particular pulse-coded RF signal coding system transmits calls for emergency service to a home/office receiver which, in turn, is routed through telephone network to a central monitoring office. The invention involves wireless transmission and routing from a single point to point, but does not involve collection of physiological data, nor the transmission, buffering, or analysis of such information.
U.S. Pat. No. 5,549,117 describes a system for monitoring and reporting medical measurements which collect data on a remote stand-alone monitoring system into a relational database. The remote unit provides a means for generating reports and transmitting them to a health care provider. The disclosure is principally directed toward respiratory function sensors.
U.S. Pat. No. 5,558,638 describes a system for monitoring the health and medical requirements of a plurality of patients using a base unit located at each patient to connect to a number of sensors and/or recorders. The base unit stores the data which is transferred to a care center which analyses the data. The care center can also communication with the base unit through a local area network. No evidence is given for hardware support for EEG or other vital signs measurements from a general purposed programmable analog input system, nor is a method for data encapsulation described.
U.S. Pat. No. 5,590,648 describes a personal heath care system which supports a plurality of patient monitoring sensor modules, but does not support multi-function analog inputs. A data processor with data communications modem is described, but not a wide/local area network connections coupled to a distributed encapsulated data collection, buffering, routing, and analysis system. Means are not provided enabling one or multiple patients to be monitored by one of many monitoring stations.
SUMMARY OF THE INVENTION
The subject invention satisfies the need for a general-purpose, low-cost system which provides comprehensive physiological data collection, with extensive data object oriented programmability and configurability for a variety of medical as well as other analog data collection applications. In a preferred embodiment, programmable input signal acquisition and processing circuits are used so that virtually any analog and/or medical signal can be digitized from a common point of contact to a plurality of sensors. A general-purpose data routing and encapsulation architecture supports input tagging and standarized routing through modern packet switch networks, including the Internet; from one of multiple points of origin or patients, to one or multiple points of data analysis for physician review. The preferred architecture further supports multiple-site data buffering for redundancy and reliability, and real-time data collection, routing, and viewing (or slower than real-time processes when communications infrastructure is slower than the data collection rate). Routing and viewing stations allow for the insertion of automated analysis routines to aid in data encoding, analysis, viewing, and diagnosis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of a single portable/wearable medical instrument according to the invention;
FIG. 2A is a drawing which shows how distributed collection may be used to support potentially unlimited input bandwidths;
FIG. 2B illustrates how collection nodes may be physically separated to perform desired tasks;
FIG. 3 is a block diagram of a programmable amplifier according to a preferred embodiment of the invention;
FIG. 4 illustrates a physical layout of one programmable amplifier board;
FIG. 5 is an illustration of a distributed power supply;
FIG. 6 illustrates a connection configuration between a mother board and daughter cards;
FIG. 7 is a drawing which shows a front display and switch panel;
FIG. 8 provides two oblique views a physical layout of a system according to the invention;
FIG. 9 is a block diagram of a portable portion of the inventive system;
FIG. 10 illustrates how the invention provides a point of collection and digitization for multiple types of medical data;
FIG. 11 illustrates how, according to the invention, and underlying architecture may be based upon standard data encapsulation;
FIG. 12 is a drawing which shows the basic architecture of the invention as a hierarchy of collection-databasing nodes;
FIG. 13 illustrates how logic in a data interface library is used to connect a data source node to effect data upload on demand to complete a local data stream for a particular data request; and
FIG. 14 is a screen display which shows command interface data plotted as a strip chart and video displayed in a video window.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to medical instrumentation and a methodology for use involving object-oriented measurement, collection, communication, and analysis. In terms of physical configuration, the apparatus is preferably in the form of a small, portable/wearable system supporting programmable measurement of multiple physiological signals from a plurality of sensor types, attached via remote collection, communications, and networking capabilities, to systems which support signal and signal feature analysis and interpretation.
Broadly, and in general terms, important features of the invention include:
(1) All data are read through programmable multi-sensor analog input processing stages, which are software configurable for signals ranging from very small signal EEG to very large signal volume or blood pressure sensors;
(2) All data are time and source tagged for integration into the spatial/temporal reality;
(3) All data are either self-descriptive, or encapsulated and object-oriented, so that at any point in the network any software system can acquire data by specific temporal/spatial or content features, and can understand the basic structure of the data items (i.e. data types). This facilitates standardized processing functions for specific data types which are available on each processing platform or collection/buffering/routing site, and further allows for extending these built-in functions through applications specific codes associated with specific data/record types. For ease of functional extension, a heterogeneous programming language environment and operating system environment is supported through use of standard program and data description languages;
(4) All data is transmitted and buffered to ensure delivery from input point to all processing/output points;
(5) Standard networking models support any reasonable network topology (i.e. support any number of patient collection modules delivering data to any number of patient data viewing/analysis stations), and exploit all relevant hardware network implementation standards (ranging from FDDI to RF/Wireless, satellite to land fixed). The network substructure must support geographic distribution of data sources and sinks (i.e. both wide-area and local-area networks); and
(6) The standards underlying the system are based on public standards and language coding methods for computing system and operating systems independence.
A drawing of a single portable/wearable device according to the invention is illustrated in FIG. 1. The device is a comprehensive data collection system, capable of capturing multiple channels of physiological data from a variety of different sensor types. This functionality is achieved through a highly programmable design that allows for adaptation of each channel to any sensor type. The designed system allows for remote operability through its small (portable/wearable) size, long-term battery operation, high capacity data storage, and wireless or wired networking capabilities.
The device preferably uses a PCM/CIA interface for customization of system features through the use of standard PC-card modules. These PC-card modules may include:
Analog-to-digital converter (12) for sampling processed analog signals;
Data storage (14) in the form of a hard drive, flash RAM, and so forth;
Communications via Ethernet (16), modem (18), wired, wireless, etc; and
Optional features such as GPS location unit (19).
In addition, the system defines a standard ISA derived digital bus which is augmented by inclusion of a standard analog bus which supports multiple precision, programmable, variable-gain, variable filtering analog preamplifier/isolation amplifier stage cards. One benefit of PC-cards is that both the designer and the user can choose the means of communication between a remotely-used device and separated monitoring workstation (wireless or wired network communications), as well as the method of data storage (hard-disk drive or flash memory). In addition, data recorded over a 24-hour period and stored in the remote device can be transferred instantly to an analysis system containing a compatible PC-card slot, eliminating potentially long upload times.
The preferred implementation is based on an X86 CPU for its universal compatibility, however any appropriate CPU architecture may be employed. A modular design allows for use of different CPU boards to optimize the tradeoff between power consumption and computational requirements for a given application. For instance, for applications where additional processing power is desired a 486 processor can be substituted for a 386 processor, with no other hardware modifications required.
Software is used to support communications with other devices using TCP/IP protocol over a variety of different hardware media, including RS-232, ethernet, wireless modem, etc. This feature allows for simultaneous, real-time monitoring of multiple remote monitoring systems from one or more workstation or portable computer. Additional inventive software running on each workstation provides for both the display and analysis of features for real-time and post-acquisition evaluation of measured physiological signals, as depicted in FIG. 2. Additional details are provided below with respect to the software infrastructure according to the invention.
The configurable and programmable nature of the system allows for the adaptation of any channel to a variety of sensors for measuring signals including: ECG, EMG, EEG, EOG, respiration, blood pressure, oximetry, and many other physiological signals and measurements. Compatible sensors include standard surface electrodes, active electrodes, strain gauges, pressure transducers, outputs from sensor modules such as oximetry or non-invasive blood pressure, and virtually any other applicable sensor type.
One means for achieving the highly programmable nature of the apparatus is through the incorporation of an inventive differential amplifier and signal conditioning circuit that provides extensive programmability through digital control lines. FIG. 3 is a block diagram of the programmable amplifier circuitry, and the following list summarizes the primary features of the amplifier design:
Microprocessor-compatible, optically isolated, 3-wire serial interface;
Optically-isolated analog output voltage;
Board-level power supply conditioning;
Less than 1 μV RMS equivalent input noise (gain>1000);
Wide input voltage range (±5 V);
Gain programmable from 1 to 300,000;
AC/DC coupling programmable with four highpass cutoff frequencies;
Programmable baseline restoration following saturation;
60-Hz notch filter programmable;
4-pole low pass filter with eight programmable cutoff frequencies;
DC offset adjustment programmable; and
Patient and equipment protection through current limiting stages and shunting elements.
FIG. 4 illustrates a physical layout of one programmable amplifier board. Two programmable amplifier channels on a single PCB comprise a daughter-card which interfaces to a motherboard via a high-density connector. This connector supplies an input signal, isolated power, and a programming bit to each isolated amplifier channel, as well as to the two remaining common serial interface lines and a common power supply. The common serial interface lines are optically isolated twice on the amplifier board, once for each isolated amplifier channel, and supplied to each channel in addition to its respective isolated programming bit to yield the isolated 3-wire serial interface. The common power supply provides power to the output stages of the analog optical isolation stages of each channel. Additionally, the isolated analog output signals are carried from the amplifier board to the motherboard.
The system in which the amplifier card is used is not only designed to accommodate a programmable amplifier board, but a variety of other auxiliary function boards, including but not limited to pulse oximetry, noninvasive blood pressure, impedance respiration, or any combination of these functions. Data can be supplied to the system not only in analog form, as is done for the amplifier cards, but also digitally using the two available RS-232 ports which are accessible to a card inserted into the appropriate position (for non-PC implementations other digital ports can be included in the design concept). Therefore, nearly any control or acquisition function can be accomplished using these two interface types.
Digital Optical Isolation
Digital optical isolation of each of the 3-wire serial interfaces for each amplifier channel is performed on the amplifier board, preferably through the use of NEC high isolation voltage photocouplers (PS2801-4) having a high 2.5 kV isolation voltage.
Microprocessor interface: Serial to Parallel Shift Registers
The programmable amplifier board receives its control via a microprocessor compatible 3-wire serial interface. This interface includes a clock line, a data line, and a programming line. Both of the amplifier channels on a given amplifier card share the same clock and data lines, but have individual programming lines. The serial interface drives a pair of serial input, parallel output 8-bit shift registers which generate the 16-bit programmable data bus for the given amplifier channel. The 16 data bits are clocked on the data line with the programming bit asserted low. Following the 16 data bits, on the rising edge of the programming bit the 16 data bits are latched onto the parallel data bus.
Protection Circuitry
Patient protection consists of a series current-limiting resistance which limits the fault-mode patient leakage current to 30 uA via the electrode interface. Under normal operation, the patient leakage current via the electrode interface is limited to the leakage current of the isolated supply circuitry (pA), the leakage current of the input filtering capacitance (pA), and the leakage current of the instrumentation amplifier (pA).
Amplifier protection consists of a pair of fast-switching diodes tied to the supply rails which will limit the voltage at the input of the differential amplifier to the supply rail voltage plus approximately 0.7 V. This protection, combined with the 0.1W series current-limiting resistance is capable of protecting the input of the amplifier from exposure to 110 V, 60 Hz line supply. Additional amplifier protection can be implemented on the motherboard to allow for protection from high voltage, high-power transients such as a defibrillator pulse.
Programmable Instrumentation Amplifier
The differential input signal supplied to each amplifier channel is amplified by a programmable instrumentation amplifier, the Burr-Brown PGA204, with programmable gains of 1, 10, 100, and 1000. This amplifier combines a high input impedance, low input noise, high common-mode rejection ratio (CMRR), and programmable gain in a single package. The gain of the instrumentation amplifier is selected by data bits 0 and 1 of the parallel data bus.
Programmable AC Coupling
In many cases it is necessary to remove the DC component of an input signal, particularly when employing high system gain. The remaining portion of the AC coupled signal can then be amplified further without saturation of the output due to a DC component which is often of much greater magnitude than the AC signal of interest. In order to most effectively reduce the DC component of the signal, an integrator is placed in a feedback loop between the output of the instrumentation amplifier and its reference. Thus, any DC component of the input is effectively subtracted from the output of the instrumentation amplifier. To allow for flexible use of this amplifier, this AC coupling feature is programmable, with choices of DC coupling or AC coupling using one of four selectable cutoff frequencies. These cutoff frequencies are shown in Table 1. For DC coupling, the integrator is removed from the feedback loop by an analog switch which then supplies a buffered ground signal to the reference pin of the instrumentation amplifier. AC or DC coupling are selected using bit 5 of the parallel data bus, while the AC cutoff frequencies are selected by bits 2 and 3.
TABLE 1______________________________________Feature Description______________________________________AC/DC Coupling Programmable with 4 cutoff options (programmable): 0.01 Hz 0.1 Hz 0.5 Hz 20 HzHighpass Filter 4-pole HPF, with 4 cutoff options (programmable): 0.01 Hz 0.1 Hz 0.5 Hz 20 Hz60 Hz Notch Filter Programmable in/outLowpass Filter 4-pole LPF, with 8 cutoff options (programmable): 20 Hz 50 Hz 100 Hz 200 Hz 500 Hz 1000 Hz 5000 Hz 10000 HzDC offset adjustment Programmable: -4.1 to +4.1 voltsGain Programmable: 1 to 300,000 with 10 increments per decadePower system Individually isolated channelsCMRR 120 dB @ 10 Hz 107 dB @ 100 Hz 87 dB @ 1 kHzNoise Level <1uV RMSUser Protection Current limiting (30 uA)______________________________________
Programmable Baseline Restoration
When using the lower AC coupling or highpass filter cutoff frequencies and the amplifier saturates due to a large input, the output takes a great deal of time to return to baseline due to the long time constants of the integrator and highpass filter. In many instances this behavior is not tolerable due to the loss of potentially valuable data. In order to restore the output of the amplifier channel to its correct value following saturation, a baseline restoration circuit has been incorporated which takes advantage of the programmability of the AC coupling and highpass filter cutoff frequencies. The output of the instrumentation amplifier is buffered then passed through a full-wave rectifier. The output of the rectifier is compared to a reference voltage representing amplifier saturation. When saturation is detected, the comparator output goes from a logical low to a logical high, which, if baseline restoration is enabled, switches the integrator and highpass filter cutoffs to their highest setting. This provides the quickest return of the signal from its saturated state to its correct output, at which time the cutoffs are restored to their programmed value. This baseline restoration feature is controlled by data bit 15 of the parallel data bus.
Programmable Highpass Filter
A 4-pole highpass filter has been implemented based upon a unity-gain voltage-controlled-voltage-source (VCVS) analog filter. The four cutoff frequencies are selected using differential analog multiplexers controlled by data bus bits 2 and 3 to simultaneously switch between the cutoff-selection resistors of each of the two stages of the VCVS filter.
Programmable 60 Hz Notch Filter
A programmable 60-Hz notch filter has been implemented using a bootstrapped twin-T configuration. The notch frequency of the filter is fixed by the choice of component values, while the notch depth is configurable as either 0 dB (notch filter "out") or approximately 30 dB (notch filter "in") by the selection either a high or low valued feedback resistance via an analog switch controlled by bit 7.
Programmable DC Offset
A programmable DC offset signal is derived from a precision voltage reference, whose output is 4.1 V. Additionally, this output is inverted via an inverting amplifier and precision 0.1% tolerance resistors to yield -4.1 V. These two voltages are tied to the end terminals of a Dallas Semiconductor digital potentiometer having 256 positions, the wiper of which determines the DC offset. When the wiper is centered, the DC offset is 0 V. Advancing the wiper position towards the positive reference voltage results in a positive DC offset ranging from 0 to 4.1 V, while advancing the wiper position towards the negative reference voltage results in a positive DC offset ranging from 0 to -4.1 V. Thus, combined with the instrumentation amplifier gain of up to 1000, as small as 16 mV may be referred to the input. The offset is controlled via the 3-wire serial interface of the digital potentiometer, which is comprised of bits 8, 9, and 10 of the parallel data bus.
Programmable Gain
The resulting DC offset is then added to the amplified input signal via an inverting summing amplifier having a selectable gain of 1 or 10 as determined by parallel data bit 6. This programmable gain is accomplished using a SPDT switch to select the feedback resistor of the summing amplifier to set a feedback-to-input resistance ratio of either 1 or 10.
A third stage of programmable gain is implemented using a Dallas Semiconductor digital potentiometer in an inverting amplifier configuration. The wiper is connected to the inverting terminal of the op amp to keep wiper current to a minimum. The gain is set by the ratio of the two terminal-to-wiper resistances, thus providing a temperature-stable and terminal resistance-independent gain stage with gains ranging from 0 to 255. The digital potentiometer is controlled via its own 3-wire serial interface, which is comprised of bits 8, 9, and 10 of the parallel data bus.
Programmable Lowpass Filter
A 4-pole lowpass filter has been implemented based upon a unity-gain voltage-controlled-voltage-source (VCVS) analog filter. The eight cutoff frequencies are selected using analog multiplexers controlled by data bus 11, 12 and 13 to simultaneously switch between the cutoff-selection resistors of the VCVS filter.
Analog Optical Isolation
Analog optical isolation has been implemented using a linear isolation amplifier design based on the LOC series of CP Clare linear optocoupler devices to provide 3750 VRMS isolation. The amplifier is configured in photovoltaic operation to enable the highest linearity, lowest noise, and lowest drift performance. The linearity is this mode is comparable to a 14-bit D/A with a bandwidth of about 40 kHz. The LED of the optocoupler is driven with a transistor buffer to maintain the highest linearity and to minimize total harmonic distortion (THD). A ±2.5 V bipolar input signal is offset by the bias resistor in the servo feedback path to create a 0-5 V unipolar signal which is passed over the optical barrier and used as the output of the amplifier module.
Channel ID
Each card channel carries its own 4-bit tri-state buffer so that all 16 channels may share the same common data channel ID bus. When a given channel is "queried," i.e. its select line is asserted low, the channel places its ID on the bus, allowing the system software to determine the way in which the unit is configured. The channel ID of an amplifier channel has been set to the 4-bit ID 0001. When no card is in place, the default channel ID is 1111 which, if both channel IDs for a given slot correspond to this value, the system software interprets as a vacant card slot.
In addition to measurement of data through circuitry on internal data cards, a serial data link can also be established with an external device, such as pulse oximeter, blood pressure monitor, CO 2 monitor, etc. This allows for simultaneous collection, time-stamping, and collection/transmission of all measured data, including that from separate devices. The system also includes a simple user interface, consisting of pushbuttons and a small graphic-capable liquid crystal display (LCD). This will allow for programmable interaction between the device and the user even during remote usage away from the linked workstation. This offers many significant opportunities for enhancing the functionality of a portable implementation of the invention, including:
device status indication (battery level, communication link status, etc.);
display of measured signals and health status;
biofeedback;
system configuration/device setup; and
event marking and categorization.
The user interface also allows for sampling of patient-supplied information and responses to questions (i.e. an electronic diary) during collection of physiological data, with time synchronization. The system preferably further includes a distributed power supply as shown in FIG. 5. This provides individually isolated power supplies to each of the amplifier/signal conditioning modules, to the auxiliary modules, and to the digital circuitry (CPU, PC Cards, LCD Display, and supporting logic).
In the preferred configuration, the digital logic power converter is located in an external "power module" which will be physically and electrically connected to the battery pack. All other power conversion components are located inside the unit. This arrangement allows for the development of different power modules optimized for particular battery chemistries and cell arrangements, as well as decreasing heat dissipation inside the device. For configurations which require extremely long-term data collection (i.e. for durations longer than the maximum that can be achieved with a single battery pack), the power module contains a small nickel-cadmium backup battery that will allow the main battery pack to be swapped without interrupting the data collection. This backup battery pack will be charged by the main pack during normal operation. The power module also contains circuitry to detect low battery voltage and to control main system power. This circuitry is optically interfaced to the CPU board to allow the software to monitor battery status and to control system shutdown.
The response to a detected low-battery condition is determined by the type of power module installed. If the power module does not support hot-swapping of battery packs (that is, if it lacks a backup battery), the software will close any pending data collections in an orderly manner and then shut down the system. If the system is configured with a power module that does contain a backup battery, a warning message will be displayed (and will also be sent to any remotely connected nodes) and a short-duration (1 to 5-minute) countdown timer will be initiated, giving the user a short time to replace the discharged battery pack while the system is being powered by the backup battery in the power module. If the main battery back is not replaced by the end of this time-out period, the system shutdown sequence proceeds as described above.
Once the system has been shut down (either due to a low-battery condition or by explicit software command), it will remain in a powered-down state until the main battery pack is disconnected from the power module and a new, adequately charged pack is connected.
For effective packaging and interfacing of the electronics, the system is preferably divided into the following four distinct board types: motherboard/backplane; CPU controller board; PCMCIA carrier board; and datacard boards (AMP board and other custom sensor interface boards). The CPU, PCMCIA, and data card boards each interface to the Mother Board as daughter cards. FIG. 6 illustrates the connector configuration of the mother board, not drawn to scale.
Front display and switch panel of the MMDS collection device is illustrated in FIG. 7. It includes provisions for 16 amplifier inputs (or alternative analog devices), CPU, Display, Disk, and four PCMCIA devices (GPS, LAN, A/D, RF Modem). FIG. 8 shows the physical layout of the system, and FIG. 9 is the block diagram of the entire portable portion of the system.
Data Collection, Encapsulation, Routing, and Analysis Architecture
The invention provides a point of collection and digitization for multiple types of medical data. The data is labeled, stored, and uploaded to a network at environment (DCE). This environment is structured into three major C++ software components: (1) the Data Interchange Library, (2) the Data Collection Environment, and the (3) Data Viewing, Analysis, and Management Environment. This environment, shown in FIG. 10, is supported on Win 32 platforms (i.e. Windows 95 and NT), Posix Platforms (i.e. Unix derivatives), and embedded system (DSPs, MS-DOS machines, and other microcontrollers). The system as currently configured supports data viewers, SQL/ODBC interfaces (to data intensive applications), AI plug-ins (CLIPS and SOAR), user plug-in functions written in multiple languages (JAVA, C, C++, Perl), and data capture subsystems (from sock/serial data/message sources, intelligent A/D-D/A subsystems, Unix/Win 32/embedded system operating systems event and network traffic measurement sources, GPS, Compass, and Head/Eye Trackers, digital video sources, and physiological data measurement sources).
The underlying architecture of the system is based on standardized data encapsulation (FIG. 11). Each data source produces data structures composed of tagged data items. Each data structure is implicitly or explicitly time stamped to the accuracy of the input systems time base (each input system is a particular computer on the data collection and management network). Each data management and input system synchronizes time through the best algorithms available ranging from use of GPS derived time to mutual synchronization over the interconnection network (through a sequence of timing data packet exchanges). Because a reliable time common base for data message tagging is inherent in the system, as data is buffered and flowed up and down the collection network, data order is well known at each point in the collection, databasing, and analysis functions of the overall system.
Through function plug-ins at each point of data buffering and management, users can added programmed functionality which initiates new data collection or output, monitors data streams as new data arrives, produces new views of the data, and/or works with precollected data either in temporal order or in arbitrary record field order (the later is supported through the SQL interface features in conjunction with an SQL compliant database system plug-in).
The basic architecture of the system is a hierarchy of collection-databasing nodes (FIG. 12), or data collection environments (DCEs). Each DCE node combines a data input subsystem, socket communications subsystem, a data caching shared memory (for object tags temporal data streams), and online disk-based buffering. Each node's communications subsystem can accept multiple streams from other sources (through socket connections) or from data input subsystems (A/D, serial, or other I/O ports). Each stream is encapsulated in the data input process (or at its data input source for data from the communication subsystems), and is stored in a shared memory interface as part of an established stream set. Each stream set, when established, support a defined data type, and relays the data stored to disk on specified intervals for permanent storage.
Through the Data Interface Library, the user can install functions or subtasks which attach to the shared memory and related functions through a set of standard C++ objects. This library allows an attached routine to instantiate data types or streams, enter new data items, retrieve items which are buffered (either in memory or on disk), instantiate data collection "drivers" and initialize/control them, and provide access to data on other node transparently, thereby making the entire data collection across multiple nodes transparently available to an application at attached at any node.
Transparent data sharing between nodes is a feature of the DCE which is important in many test, measurement, and information fusion applications. DCE nodes on separate interconnection networks share each other's buffer and disk memory to provide virtual access to the totality of data available as input to the network. The notion of the distributed collection feature of the DCE is driven by two separate considerations. First, when performing critical, real-time collection, each collection physical computer will have a specific limited input bandwidth. Thus, to support potentially unlimited input bandwidth, the collection hardware must be replicated until sufficient hardware bandwidth is available for the requisite input signal array (FIG. 2A). By using accurate time bases for data fusion across the collection array, re-integration of the data is quite feasible (assuming the time base has better resolution than the signal events being captured).
Another reason for supporting distributed collection is that in some remote monitoring applications, the collection nodes must be physically separated to perform the desired tasks (FIG. 2B). As this separation distance becomes larger, maintaining control over the collection process and communications delays begin to make data integration impossible without an integrated accurate time base for data tagging. Also, communications bottlenecks make inherent data buffering a necessity, even when communications links are reliable and high bandwidth.
As indicated previously, the DCE provides this buffering function as a combination of shared memory (i.e. RAM) and disk buffer. Thus, each node is capable of storing is own data collection locally, without direct transmission uplink to higher level nodes. Communications uplink is effected in one of two ways. First, some streams can be defined as having the property that they always stream data up to high level nodes. These streams "offer" data, usually for real time monitoring of the data collection process at the higher level node. Quite often, it is assumed at the higher level node that the data being send is "abridged" because of bandwidth limitations in the communications links. As such the upper level node knows that its datasets are only partially correct and thus, knows that if a functions requiring complete information is executed, the data gaps must be filled in, perhaps at slower than real time rates. This abridged, or real-time data transfer mode is useful when monitoring the progress of testing or field operations, where maintaining real time situational awareness is more important than capturing, viewing, analyzing every data item (recall, that using the real time mode does not preclude reverting back to full data viewing later, because all the data collected is stored on its source node).
If an attached application requests data from a DCE buffering subsystem which is not locally present (i.e. data is either not being linked up from a lower level node or is being uplinked in real time mode with abridgment), logic in the Data Interface Library can connect to the data source node and can effect data upload on demand to complete the local data stream for the data request (FIG. 13). This capability makes all data for all collection and input nodes logically available on any DCE node for any attached function. Of course, this feature does not guarantee real time data availability unless the source node and the destination node are connected through communications links which are fast enough to hold up real time transfers. Since all data inputted is time stamped at it input source, data items are temporally consistent throughout the system so that data assimilated from multiple sources and uplinked at multiple times can still be consistently re-integrated.
The numerical references of FIG. 13 are defined as follows:
(1) DCE attached function requests a data stream segment;
(2) Shared memory is check for the item and if fails to contain it proceed to (3), otherwise return item;
(3) Attached disk buffer indexes are checked and if fails to contain it proceed to (4), otherwise read item into shared memory and return it;
(4) Data Interface Library requests data item from connected DCE which sources data stream;
(5) Data request is converted to a socket or serial data request to the downstream DCE;
(6) The downstream DCE executes (2)-(4) and routes the item found to the upstream DCE;
(7) The item is returned to the requesting DCE through socket or serial communications;
(8) The data item is entered into Shared Memory;
(9) The item is saved in the disk buffer (whenever Shared Memory is saved periodically); and
(10) The item is returned to the requesting attached function.
As indicated previously, functions can be attached through the Data Interface Library, to any DCE node. Some of these functions are pre-compiled code (typically C or C++, but alternatively any other language which can support a C, C++ linkage). In Win 32 systems, precompiled functions are in the form of executables or DLLs. On Unix systems they are executables or share library routines. Examples of precompiled codes already provided for within the system are device drivers (routines which read data to or from hardware interfaces such as A/D-D/A ports, serial ports, video capture interfaces, etc.), data compression/decompression routines (includes data compression/decompression, data reformatting routines, and encryption/decryption routines), and heavy compute functions (such as data filters, FFT/DFT, spectrum analysis, etc.)
Some attached functions are interpreted or shelled functions, supporting languages like Perl, JAVA, or other CGI/Shell languages. These interpreted functions provide the user a means for implementing "throw away" functions quickly and easily. The function attachment method has also been used to implement a set of AI subsystems for pattern recognition, diagnostics, and model-based reasoning. The include CLIPS (a C-based expert system shell), SOAR (a more sophisticated expert system with learning), limit checking and decommutation (a simple indicator subsystem for satellite system diagnosis), and adaptive network processing (Neural Nets).
Device Drivers serve as initial points of entry for data into the system. The basic form of a driver is as an attached function. Each DCE has a command interface, similar to TELNET and FTP. This command interface allows a remote user to examine the suite of attached functions (including drivers) available at the node, supports adding and deletion of functions, data sets, and other configuration files, and provides a uniform minimum set of commands for controlling DCE function load/unload, requesting data set uplink/downlink, assessing node status. This interface also supports scripting and passthrough of commands to subsidiary DCE nodes (thus, an entire network can be initialized and parameterized from a single command script initiated at a top level node). Through this interface, drivers can be selected, initiated, and killed. Each driver can be loaded and initialized, can be started for collection, can be monitored (the real time uplink of data abridged to the capacity of the communication link), and buffers data into the shared memory/disk buffers for virtual data access throughout the network of nodes. When data collection is completed, the driver can be killed.
Drivers act as the interface between hardware devices and the object-abstracted data collection environment. Typically, drivers live on embedded DSPs or on small simple systems (like those running OS-9 or MS-DOS). In this environment, the driver directly attaches to hardware interrupts, read and write device registers, and makes the calls available in the Data Interface Library to encapsulate data items into object-oriented stream elements. From that point on, the standard DCE functionality takes over to distribute the data throughout the network. This principle of earlier possible data encapsulation can be violated for performance reasons, but is generally adhered to because it makes the rest of the data collection environment uniform and each data item independent. The Data Interface Library supports data collection bandwidth from the core MMDS physiological monitor and at up to 16,000 data items (float scalars) per second from a 486DX2 embedded processor attached to a local Intranet. it supports capture of real time video, packet/event capture, eye track data capture, serial data capture, etc (640×480, full color; nominally 1 mbyte per second) from a Pentium Pro 200 to a similar network connection. Thus, with adequate computational horsepower, full data encapsulation at the driver represents a reasonable approach to data abstraction.
It should be noted that many drivers are more abstract than direct hardware connections. For instance, a driver embedded in Unix systems can monitor network data packet traffic. Event monitors in Windows and Unix systems capture key, window, and mouse events to monitor operation of selected user interface applications. Drivers which read standard socket and serial streams can parse inputs from attached devices. In a satellite telemetry application currently under development, the driver reads data frames from the satellite down link, decommutate the data, and encapsulates it as though it came from an array of parallel analog input devices. Thus, inputs can be anything from video sequences, to a series of messages.
Another special function type is the viewer. While it is possible to the control the DCE network through the command scripting language of a DCE node or through custom implemented functions, this approach provides a limited range of built-in data views. Control of a data collection and assimilation network is normally effected through a viewer. The Data View framework allows the user to connect to a DCE through an application designed to execute functions which generate data views and control interfaces. The Viewer framework provides the interfaces for selecting DCE nodes, feeding them scripts (and generating scripts from dialogs), checking status, and executing functions which perform analysis and/or create data displays. The viewer framework also provides interfaces to editors and language environments so that quick plug-in functions (in Perl, JAVA, etc.) can be created, edited, and attached to a DCE node for execution.
Viewers, or functions typically instantiated from within the Data Viewer framework, read data items from the environment through the Data Interface Library and present this data to the user in a viewer specific way. For instance, standard viewers include visualization of text message sequences (in a scrolling window similar to an X-term), Audio/video display windows (for video data streams), strip charts, bar graphs, spectrograms, etc. for numerical data streams, and specialized views for location, tracking, and physiological data streams. Users may implement application specific customized viewers easily because the basic framework is available as a template, and all data access functions are encapsulated within the Data Interchange Library. However, the GUI management functions associated with views are Unix or Win 32 platform dependent (X-based viewers can be executed on Win 32 platforms with an X-terminal task).
The viewer framework also supports attached functions which accept time from the framework (in synchronization with displays). This allows the user to create synthesized data streams which are dynamically created through computation based on combinations of existing real streams. FIG. 14 shows some displays from the current implementation of the Data Viewing Environment. This view shows command interface, data plotted as a strip chart, and video (displayed in a video windows). | A general-purpose, low-cost system provides comprehensive physiological data collection, with extensive data object oriented programmability and configurability for a variety of medical as well as other analog data collection applications. In a preferred embodiment, programmable input signal acquisition and processing circuits are used so that virtually any analog and/or medical signal can be digitized from a common point of contact to a plurality of sensors. A general-purpose data routing and encapsulation architecture supports input tagging and standardized routing through modern packet switch networks, including the Internet; from one of multiple points of origin or patients, to one or multiple points of data analysis for physician review. The preferred architecture further supports multiple-site data buffering for redundancy and reliability, and real-time data collection, routing, and viewing (or slower than real-time processes when communications infrastructure is slower than the data collection rate). Routing and viewing stations allow for the insertion of automated analysis routines to aid in data encoding, analysis, viewing, and diagnosis. | 6 |
TECHNICAL FIELD
[0001] The present invention relates to the field of gaseous breath detection systems, and methods for using the same, and more particularly, to the field of portable personal gaseous breath detection apparatus and methods for using same.
BACKGROUND OF THE INVENTION
[0002] There are several methods for determining the alcohol content (or level) of a person's breath. A common method is to use a tin-oxide semiconductor alcohol sensor. It has the advantage of low cost at the expense of accuracy, alcohol specificity, and electrical power consumption. Another method is to employ the use of an electrochemical fuel cell alcohol sensor. While this type of sensor tends to be more accurate, more alcohol specific, and utilizes less electrical power, the sensor itself is significantly more expensive and has traditionally required the use of an active sampling mechanism such as a pump. The pump adds cost and size to the device, and utilizes electrical power. Both methods also typically require the use of a pressure sensor to determine when the user is blowing into the device.
[0003] Accordingly, it is desirable to have a breath detection apparatus that utilizes an electrochemical fuel cell alcohol sensor for accuracy, alcohol specificity, and low power consumption, and eliminates the need for a sampling mechanism, saving more in cost, power consumption, and size. Furthermore, it is desirable to have such breath detection apparatus with the traditional pressure sensor eliminated in favor of a configuration that utilizes a temperature sensor as a flow sensor, thus saving in the size and cost of the device.
SUMMARY OF THE INVENTION
[0004] Accordingly, it is an object of the present invention to provide an improved breath alcohol tester. In particular, it is a benefit of the present invention to provide a breath alcohol tester that combines low cost, small size, low power consumption, and alcohol specificity.
[0005] One embodiment of the present invention comprises an apparatus for detecting gaseous component levels in breath. The apparatus comprises: a breath channel; an electrochemical sensor in fluid communication with the breath channel; a processor in electrical communication with the electrochemical sensor; and computer readable storage medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; wherein the apparatus is configured to calculate approximate gaseous components levels in a breath without utilizing a sampling pump.
[0006] Another embodiment of the present invention comprises a breath detection apparatus for detecting gaseous component levels in breath. The apparatus comprises: a gas sensor; a processor in electrical communication with the gas sensor; and a computer readable storage medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and a wireless transmitter; wherein the wireless transmitter transmits a signal to an external receiver.
[0007] Yet another embodiment of the present invention comprises an apparatus for detecting gaseous component levels in breath. The apparatus comprises: a breath channel; a gas sensor in fluid communication with the breath channel; a processor in electrical communication with the gas sensor; computer readable storage medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and temperature sensor in fluid communication with the breath channel; wherein the temperature sensor is utilized to determine breath flow rate.
[0008] Still another embodiment of the present invention comprises a method for detecting gaseous component levels in breath, The method comprises: obtaining an initial signal from a temperature sensor; monitoring the temperature sensor for a temperature change; calculating airflow rate utilizing the temperature sensor signal; and calculating gaseous component levels in breath utilizing airflow rate.
[0009] Yet another embodiment of the present invention comprises a method for detecting gaseous component levels in breath. The method comprises: receiving a breath stream in a breath channel; obtaining a signal from an electrochemical sensor; and calculating a gaseous component level in breath utilizing the electrochemical sensor.
[0010] One embodiment of the present invention comprises an apparatus for detecting gaseous component levels in breath. The apparatus comprises: a breath passage having a flowpath, a proximal end and a distal end, wherein the proximal end comprises an inlet for accepting a person's breath and the distal end comprises an outlet for venting the breath; a temperature sensor in fluid communication with the flowpath; an electrochemical sensor in fluid communication with the flowpath; a processor in electrical communication with the temperature sensor and the electrochemical sensor; and a computer readable storage medium in electrical communication with the processor, wherein the computer readable medium contains executable instructions for the processor; wherein the apparatus is configured to approximate gaseous component level in the breath without utilizing a sampling pump.
[0011] Another embodiment of the present invention comprises an apparatus for detecting gaseous component level in breath. The apparatus comprises: a breath channel; a gas sensor in fluid communication with the breath channel; a processor in electrical communication with the gas sensor; a computer readable storage medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and wherein the apparatus is configured to approximate gaseous component level in a breath without utilizing a sampling pump; and further wherein the apparatus is configured to cease functioning at a pre-determined time.
[0012] Yet another embodiment of the present invention comprises an apparatus for detecting gaseous component level in breath. The apparatus comprises: a breath channel; a gas sensor in fluid communication with the breath channel; a processor in electrical communication with the gas sensor; a computer readable storage medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and wherein the apparatus is configured to approximate gaseous component level in a breath without utilizing a sampling pump; and further wherein the apparatus is configured to cease functioning outside a pre-determined temperature range.
[0013] One embodiment of the present invention comprises an ignition interlock system. The system comprises: the breath detection apparatus and a wireless receiver; a computing device in electrical communication with the wireless receiver; a computer readable storage medium in electrical communication with the computing device, wherein the computer readable medium contains executable instructions for the computing device; a switch in electrical communication with the computing device and ignition control line of a vehicle; wherein the wireless receiver is configured to receive signals from the breath detection apparatus.
[0014] Yet another embodiment of the present invention comprises an identification system for a breath detection interlock system. The system comprises: a wireless transmitter and receiver; a processor in electrical communication with the transmitter and receiver; a computer readable medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and wherein the executable instruction comprise instructions to maintain a continuous signal between the transmitter and receiver.
[0015] Still another embodiment of the present invention comprises an identification method for a breath detection system. The method comprises: confirming a user's identity; maintaining a continuous signal between the transmitter and receiver after the identity has been confirmed; and if the signal between the transmitter and receiver is not continuous, aborting the breath detection system and restart the system.
[0016] Another embodiment of the present invention comprises an identification system for a breath detection interlock system. The system comprises: a passive infrared detector; a processor in electrical communication with the detector; a computer readable medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and wherein the executable instruction comprise instructions to monitor infrared signals utilizing the passive infrared detector.
[0017] Yet another embodiment of the present invention is an identification method for a breath detection system. The method comprises: confirming a user's identity; maintaining a continuous signal between the user and the passive infrared detector; and if the signal received by the passive infrared detector is not continuous, aborting the breath detection system and restart the system.
[0018] Another embodiment of the present invention is an identification system for a breath detection interlock system. The system comprises: a motion sensor; a processor in electrical communication with the motion sensor; a computer readable medium in electrical communication with the processor, wherein the computer readable storage medium contains executable instructions for the processor; and wherein the executable instruction comprise instructions to monitor the movement of the motion sensor.
[0019] Still yet another embodiment of the present invention is an identification method for a breath detection system. The method comprises: confirming a user's identity; monitoring a motion sensor output; and if the signal received by the motion sensor exceeds a pre-determined threshold, abort the breath detection system and restart the system.
[0020] Another embodiment of the present invention is an identification method for a breath detection system. The method comprises: confirming a user's identity; and initiating a countdown timer executable instructions, wherein if a breath test has not been initiated by the lapse of the count down timer, abort the breath detection system and restart the system.
[0021] In one aspect of the present invention, when the user blows into the device, a temperature sensor which is connected to a controller and is situated in the breath channel portion of the device detects that the user is blowing and at what flow rate. The breath channel is also directly connected to a electrochemical fuel cell ethanol sensor that gives an electrical output when it is exposed to ethanol in the breath. The positioning of the ethanol sensor directly in the breath channel eliminates the need for a mechanical sampling system. The ambient temperature of the device is determined by the controller from the breath temperature sensor before the user starts blowing. After the user has stopped blowing, an algorithm contained within the controller can calculate the user's breath alcohol content by taking into account the flow rate, the length of time the user was blowing, and the temperature of the ethanol sensor.
[0022] In another aspect of the present invention, one or more safety mechanisms, prevent the device from giving an erroneous reading. The controller can shut down the device to prevent the user from taking a test if the ambient temperature is outside of a range within which the ethanol sensor can give an accurate reading. The controller can also shut down the device if the length of time that has expired since the device was constructed and calibrated is such that the output of the ethanol sensor has drifted and will no longer give an accurate reading.
[0023] In another aspect of the present invention, the system further includes a breath alcohol ignition interlock device. In this embodiment, a wireless transmitter is incorporated into the controller circuit. A physically separate controller which contains a wireless receiver is installed in the vehicle and attached to the vehicle's ignition circuit. After the user takes a breath test, the transmitter sends a signal to the receiver in the controller in the vehicle, which allows the vehicle to start if the breath alcohol level is below a predetermined level, and not allowing the vehicle to start otherwise.
[0024] The present invention also provides a method for using the breath tester as an ignition interlock for the consumer market. A separate wireless transmitter is used that allows the supervising agent (whether it be the parent, spouse, etc.) to enable the vehicle's ignition without having to take a breath test. This transmitter also allows the supervising agent to program the device with various options.
[0025] Another aspect of the present invention provides an ignition interlock for the court-mandated market. A voice recognition circuit is employed in the breath tester that requires the user to speak one or more words into the device before taking the breath test. If the controller in the device matches the spoken words to those that were previously stored in the device when it was trained by the intended user during installation, then a subsequent breath test will be allowed. If the words are not matched, then a breath test is not allowed. To insure that the device cannot be passed to another individual after the words are spoken by the intended user, several methods may be employed: allowing a short interval of time between the spoken words and the breath test; using a transmitter and receiver combination that bounces energy off the user's face and detects when the transmitted beam is interrupted; using a motion sensor that detects if the device is moved quickly; using an infrared heat sensor that detects a change in sensed body heat.
[0026] Still other objects and advantages of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described exemplary embodiments of this invention, including a best mode currently contemplated for the invention, simply for purposes of illustration. As will be realized, the invention is capable of other different aspects and embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood from the following description taken in conjunction with the accompanying drawings in which:
[0028] [0028]FIG. 1 is an operational block diagram of a breath alcohol tester apparatus in accordance with the present invention;
[0029] [0029]FIG. 2 is an operational block diagram of an interlock ignition system in accordance with the present invention;
[0030] [0030]FIG. 3 is an operational block diagram of a wireless master transmitter in accordance with the present invention;
[0031] [0031]FIG. 4 is a flowchart depicting an exemplary embodiment of the method of detecting breath alcohol levels;
[0032] [0032]FIG. 5 is a flowchart depicting and exemplary embodiment of voice verification method in accordance with the present invention; and
[0033] [0033]FIG. 6 is a flowchart depicting an exemplary embodiment of another method in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein like numerals indicate the same elements throughout the views.
[0035] Referring to FIG. 1, the personal breath tester 200 comprises a breath passage 1 having a flowpath 120 , a proximal end 100 and a distal end 102 , wherein the proximal end 100 comprises an inlet 105 for accepting a person's breath and the distal end 102 comprises an outlet 110 for venting the breath. A temperature sensor 2 is in fluid communication with the flowpath 120 of the breath passage 1 . In addition, an alcohol sensor 3 is in fluid communication with the flowpath 120 of the breath passage 1 . In an exemplary embodiment, the temperature sensor 2 and/or alcohol sensor 3 are physically contained within the flowpath 120 of the breath passage 1 . Since the alcohol sensor 3 is in fluid communication with the flowpath 120 , the need for a mechanical pump or sampling system is eliminated.
[0036] In one exemplary embodiment, the temperature sensor 2 comprises a thermistor sensor and the alcohol sensor 3 comprises an electrochemical fuel cell with an ethanol sensor. The temperature sensor 2 is in electrical communication with two resistors 13 and 14 . The resistor 14 is in electrical communication with an electrical switch 15 , which in turn is in electrical communication with a computing device 4 . The temperature sensor 2 is also in electrical communication to an amplifier 10 for generating a signal representative of flow rate. The output signal of the flow amplifier 10 is in electrical communication with the analog-to-digital converter 16 , which converts the output signal into a digital number that can be interpreted by the computing device 4 , such as a microprocessor.
[0037] The alcohol sensor 3 is in electrical communication with an amplifier 11 . The output signal of the amplifier is in electrical communication with the analog-to-digital converter 16 , which converts the output signal into a digital number. The output signal of the analog-to-digital converter is connected to the computing device 4 .
[0038] A display 5 , which in one exemplary embodiment comprises an alphanumeric display, is driven by a display driver circuit 18 . The display driver circuit 18 is in electrical communication and is controlled by the computing device 4 . In another exemplary embodiment, the present invention further comprises a speaker 7 , which is controlled by an amplifier 17 , wherein the amplifier is controlled by the computing device 4 . A momentary switch 6 and a communication channel 8 are in electrical communication with the computing device 4 .
[0039] In one exemplary embodiment of the present invention depicted by FIG. 4, a breath test is initiated when a person depresses the switch 6 (step 305 ) of the personal breath tester 200 . When the computing device 4 determines that the switch 6 has been depressed, the computing device 4 obtains the initial temperature of the temperature sensor 2 by opening the switch 15 , converting the temperature sensor 2 output signal into a digital number with the analog-to-digital converter 16 , and recording that number as the starting value of the temperature sensor 2 (step 310 ). If the recorded starting value of the temperature sensor 2 is less than 32° C. or greater than 36° C., the switch 15 is left open and the personal breath tester 200 is ready to begin testing breath samples. If the recorded starting value is equal to or more than 32° C. and less than or equal to 36° C. (step 315 ), then switch 15 is turned on (closes circuit) by the computing device 4 (step 320 ) to increase the temperature level to that greater than expected human breath (i.e. 34° C.).
[0040] When switch 15 is turned on, the resistor 14 is placed in electrical communication with the temperature sensor 2 , causing a significant increase in current to flow through the temperature sensor 2 . After a short amount of time, this causes heating of the temperature sensor 2 , and the internal temperature will rise significantly above 34° C.
[0041] Once a suitable initial temperature has been obtained (i.e. less than 32° C. or greater than 36° C.), whether switch 15 is on or off, a person blows into the breath passage 1 of the personal breath detector 200 . The temperature of the person's breath is typically 34° C. The stream of air blown into the breath passage will cause the temperature of the temperature sensor 2 to change.
[0042] If the initial temperature of the temperature sensor 2 immediately before blowing is below 32° C., then the temperature will rise with blowing. Similarly, if the initial temperature of the temperature sensor 2 is above 36° C., then the temperature will fall with blowing.
[0043] This change in temperature is amplified by the flow amplifier 10 , converted into a digital signal by the analog-to-digital converter 16 , and then sent to the computing device 4 . The change in temperature is an indication that the user is blowing, and the rate at which this temperature change occurs is an indication of the flow rate (step 325 ). A quick change in temperature indicates a higher flow rate than a slow change in temperature. Once the computing device 4 detects that the user is blowing, it converts the alcohol sensor amplifier 11 output into a digital number by way of the analog-to-digital converter 16 , and records that number as the baseline value of the alcohol sensor 3 (step 328 ). In an exemplary embodiment, the baseline value is stored in a computer readable memory unit 160 .
[0044] The computing device 4 calculates the flow rate (step 330 ) and compares it to a minimum flow threshold value, which is stored in the computing device or computer readable memory unit 160 . If the flow rate is higher than the minimum (step 335 ), then the computing device 4 starts an internal flow timer (step 345 ). Once the person stops blowing air into the breath passage and/or the air flow rate drops below the minimum threshold value (step 350 ), then the computing device 4 records the flow timer value as an indication of how long the person was blowing air into the breath passage at an acceptable rate (i.e. above minimum threshold value) (step 355 ). If the recorded flow timer value is less than a minimum timer threshold value (step 360 ), stored in the computing device, then the computing device 4 aborts the breath test (step 370 ), and sends a visual abort indication to the user. In one exemplary embodiment, the abort indication is a visual indication on the personal breath tester (i.e., such as a display 5 ). In another exemplary embodiment, the abort indicator is an audible signal through a speaker 7 (step 375 ). If the recorded flow timer value is less than the minimum timer threshold another breath test must be initiated by the person. The minimum flow rate and flow timer threshold values exist to insure that the person taking the test is providing a minimum volume of deep-lung (alveolar) air into the device.
[0045] As long as the minimum flow rate and flow timer threshold values are exceeded, the computing device 4 calculates the blood alcohol level (step 380 ). In one exemplary embodiment, the fuel cell alcohol sensor sends a signal to the amplifier 11 . The amplifier 11 sends an amplified signal to the analog/digital converter 16 . The analog/digital converter 16 sends the digital signal to the computing device 4 . The computing device 4 retrieves from a computer readable memory storage unit 160 , the previously recorded baseline value for the alcohol sensor. The computing device 4 then calculates an equivalent breath alcohol level using an algorithm incorporating the baseline value, the flow rate, the length of time blowing, the temperature of temperature sensor 2 and a calibration factor accounting for variations in output from sensor to sensor. The breath alcohol level is then indicated on the display 5 as a digital number (step 385 ), along with an audible indication on speaker 7 that the test is completed.
[0046] If the embodiment includes an ignition interlock device, the computing devices would then transmit the level and/or a signal to the ignition interlock system (step 390 ).
[0047] [0047]FIG. 2 depicts an exemplary ignition interlock system. The ignition interlock system 65 is located in the vehicle, and contains a computing device 20 , a wireless receiver 19 , and a relay 21 that controls the vehicle's ignition circuit 22 . When the receiver 19 receives the breath alcohol level from the personal breath tester 200 , the computing device 20 compares the breath alcohol level to a stored predetermined level. If the received level is below the predetermined level, the relay 21 is engaged by the computing device 20 , allowing the ignition control line 22 to enable starting of the vehicle. If the received level is at or above the predetermined level, then the relay is not engaged and the vehicle will not start.
[0048] In another exemplary embodiment depicted in FIG. 5, the personal breath tester is used as an ignition interlock device for a court-mandated market. When the user depresses switch 6 (step 500 ), the computing device 4 will send instructions to the voice identification circuit 23 that it should listen for a word spoken by the user (step 505 ). The computing device 4 will also give an indication to the user via the display 5 and the speaker 7 that the user is to hold the device in close proximity to his or her lips and say the word that the circuit has been trained for. After the user says the word, the voice identification circuit 23 will send a signal to the computing device 4 that either confirms or denies the correct identity of the user (step 510 ). If the correct identity is denied, then the computing device 4 will give such an indication to the user via the display 5 and the speaker 7 (step 515 ), and will then power down (step 516 ). If the correct identity is confirmed, then the computing device 4 will start an internal count down timer (step 520 ). If the timer expires before the user starts blowing into the device, then the computing device will indicate an abort situation to the user via the display 5 and the speaker 7 , and then power down (step 525 ). The starting timer value is set short enough as to not allow the user to speak the verifying word and then pass the device to another person for the breath test. As alternate methods, if the correct identity is confirmed, then the computing device 4 will look for: 1) an interruption of the received infrared signal as indicated by the infrared transmitter/receiver circuit 24 before blowing has started; 2) an interruption of the received infrared energy from the passive infrared detector circuit 25 before blowing has started; or 3) the indication of excessive motion as indicated by the motion detector 26 before blowing has started. If there is no abort indication from the appropriate method indicating that the device is being passed to another person, then the breath test will proceed as described above (step 530 ).
[0049] In yet another embodiment of the present invention, the personal breath tester is to be used as an interlock device for the consumer market. FIG. 3 depicts a master transmitter device 60 utilized in the present embodiment which overrides the ignition interlock system 65 . It consists of a computing device 27 connected to a wireless transmitter 28 and also to switch 29 and switch 35 . When the user presses on the switch 29 , the computing device 28 sends a bypass code to the transmitter 28 . The ignition interlock system 65 of FIG. 2, which is mounted in the vehicle, receives the bypass code by way of the wireless receiver 19 . When the computing device 20 detects the bypass code, it turns on relay 21 to enable the ignition and to allow starting of the vehicle. The bypass code also puts the computing device 20 into a state wherein it will recognize the activation of any number of switches 30 attached to the computing device. The switches 30 represent programming options, such as whether or not a breath test will be required of the user while the vehicle is running. In this manner, the supervisor can program various options into the interlock that the normal user cannot access. In one embodiment of the present invention, the consumer interlock may record a violation, meaning that a breath test was not taken and passed when requested either before starting the vehicle or after the vehicle was running. If this occurs,-the violation will be recorded. Pressing switch 35 on the master transmitter will reset the violation.
[0050] An exemplary method of programming the consumer ignition interlock system 65 is depicted in FIG. 6. The computing device 20 continuously monitors the wireless receiver 19 to determine if any data has been received (step 600 ). If data is received, the computing device 20 determines whether the data is blood alcohol content results (step 610 ). If the data is blood alcohol content results, the computing device 20 determines whether the results exceed the threshold (step 620 ). If the results are less than the threshold, the relay 21 is engaged allowing the vehicle to be started (step 625 ). If the results exceed the threshold, the relay remains “off” preventing the vehicle from being started (step 630 ).
[0051] If the data received does not contain blood alcohol content results (step 650 ), the computing device 20 determines whether the data contains a bypass code (step 660 ). If the data does not contain a bypass code, the computing device 20 clears the data and returns to continuously monitoring the wireless receiver 19 (step 670 ).
[0052] If the data received does contain a bypass code, the relay 21 is engaged (step 680 ). In a further embodiment of the present invention, the switch 30 of the ignition interlock system 65 can be utilized to reconfigure the program options of the ignition interlock system 65 (step 690 ).
[0053] One skilled in the art will appreciate the various components of the personal breath tester may be obtained from a multitude of sources known to those skilled in the art. For example, ethanol fuel cell sensors may be obtained from Guth Laboratories of Harrisburg, Pa. and from Draeger Safety of Houston, Tex. Typical microprocessors that may be utilized in the present invention may be obtained from Texas Instruments of Dallas, Tex. and NEC of Santa Clara, Calif. Temperature sensors utilized in the present invention may be obtained from NIC of Melville, N.Y. and Murata of Smyrna, Ga. Typical wireless transmitters/receivers which may be utilized in the present invention may be obtained from Atmel of Heilbronn, Germany and RF Microdevices of Greensboro, N.C. Voice identification circuitry may be obtained from Sensory Circuits of Santa Clara, Calif.
[0054] The foregoing description of the exemplary embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive nor to limit the inventor to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | Apparatus for detecting blood alcohol level in breath. Apparatus has a breath channel; and electrochemical fuel cell in communication with the breath channel; a temperature sensor in communication with the breath channel; a processor in communication with the temperature sensor and electrochemical fuel cell; and a computer readable storage medium containing executable instructions for the processor. | 6 |
This invention relates to a cushion sub-assembly of a type for absorbing vibrations being transmitted to a drill head by a drill pipe during the drilling of a bore hole.
RELATED/PRIORITY APPLICATION
This application is a National Phase filing regarding International Application No. PCT/AU2009/000552, filed on May 5, 2009, which relies upon Australian Application No. 2008902183, filed on May 5, 2008 for priority.
BACKGROUND OF THE INVENTION
It is known to include a cushion sub-assembly below the drill head of a drilling rig and through which the turning force of the drill head is transmitted to the uppermost drill pipe section to thereby rotate the drill string within the bore being drilled. Such cushion sub-assemblies have taken a number of different forms, the design of which takes into account the features of the drilling operation in which the cushion sub-assembly will be used.
For example, it is common in a drilling operation to force the drilling bit into engagement with the bottom of the bore and to achieve the cutting action due to rotational motion only of the drill string and drill bit. A cushion sub-assembly designed for this type of drilling must be capable of absorbing a significant portion of both the torsional and axial vibrations resulting from the cutting action of the bit.
In downhole hammer drilling, compressed fluid is transmitted to a hammer means at the bit location and this results in additional axial vibration. Cushion sub-assemblies used for this type of drilling have therefore needed to be capable of transmitting a drilling torque as well, despite the cushion sub-assembly being primarily designed to prevent the transmission of high axial vibration forces to the drilling head. Existing cushion sub-assemblies are not satisfactory as vibration is still carried through to the rotary head.
A further problem with existing cushion sub-assemblies of this type is their tendency to wear very quickly. The internal components of the cushion sub-assembly, particularly those in contact with the reciprocating piston, require regular maintenance, refurbishment, and eventual replacement. Refurbishment of existing cushion sub-assemblies is time consuming and expensive due to the number of parts requiring maintenance. Accordingly, there is a clear commercial benefit in having a cushion sub-assembly that boasts an increased lifespan, and which is designed to be quick, simple and inexpensive to refurbish.
OBJECTS OF THE INVENTION
It is an object of the present invention to overcome at least some of the above-mentioned problems or provide the public with a useful alternative.
There is a need for a cushion sub-assembly having both axial and torsional vibration absorbing characteristics capable of effectively handling the types of forces experienced in modern drilling techniques.
There is also a need for a cushion sub-assembly having a longer wear life than is otherwise achievable with existing cushion sub arrangements whose design and internal arrangement facilitates quick, simple and inexpensive refurbishment/replacement.
The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form or suggestion that the prior art forms part of the common general knowledge in Australia.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a cushion sub-assembly for connection to a drill string to absorb vibrations in the drill string, the cushion sub-assembly including a main body defining a chamber therein, a piston member disposed within the chamber capable of axial movement at least partially within the chamber between a first and second position, at least one axially extending piston rod disposed inside a respective axial bore of the piston member, the at least one piston rod preventing relative rotation between the piston member and the main body while permitting axial movement of the piston member between the first and second positions, and a vibration absorbing means at opposite ends of the chamber for engagement by the piston member when in either of the first or second positions for absorbing axial vibrations, the configuration of the at least one piston rod inside the piston member, and engagement of the piston member with the vibration absorbing means serving to minimize transmission of axial vibrations between the piston member and the main body.
In one embodiment, the piston member includes a piston shaft formed integrally therewith, the piston shaft being of a stepped down diameter.
The piston member may further include a plurality of radially disposed respective axial bores extending through the piston member, the bores being disposed between the outer periphery of the piston member and the piston shaft for accommodating a plurality of the piston rods. By including piston rods running inside the piston member, not only has it been found that axial vibration is reduced, but once the cushion sub-assembly has reached the end of its wear life, relatively minimal work is required to refurbish the cushion sub-assembly for re-use. Typically, after prolonged use, the bores extending axially through the piston member become elongated and the piston rods themselves become significantly worn. Thus, in order to refurbish the cushion sub-assembly, the bores need to be bored out and made circular again, and the piston rods require replacement with rods having an appropriately larger diameter. However, in embodiments of the invention, the main body of the cushion sub-assembly does not require refurbishment or replacement because the piston rods are disposed inwards of the casing.
In one embodiment, the main body includes a casing member defining the chamber and a back head mounted to the casing member at an upper end thereof, the back head including a first connection means for rigid connection to a driving portion of the drill string.
In another embodiment, the piston shaft includes a second connection means for rigid connection to a driven portion of the drill string.
Preferably the first position of the piston member corresponds with the upper end of the main body, and the second position of the piston member corresponds with the lower end of the main body.
The vibration absorbing means may be in the form of at least one pad of elastomeric material. Further, the vibration absorbing means at the upper end of the main body may include three pads of elastomeric material, wherein the piston member engages a bottom of the three pads when in the first position. In this embodiment, the lower-most pad of elastomeric material has a first thickness and has a first grade strength, the middle pad has a second thickness which may be substantially equal to the first thickness and a second grade strength which may be substantially greater than the first grade strength, and the upper-most pad of elastomeric material has a third thickness which may be substantially thinner than the first thickness and has a third grade strength which may be substantially greater than the second grade strength.
In another embodiment, the vibration absorbing means at the lower end of the chamber includes a single pad of elastomeric material of high strength, wherein the piston member engages the single pad when in the second position.
BRIEF DESCRIPTION OF THE DRAWINGS
Once or more embodiments of the invention are described below with reference to the accompanying drawings, which are incorporated in and constitute a part of this specification. In the drawings,
FIG. 1 illustrates an exploded, perspective view of a cushion sub-assembly in accordance with a first embodiment of the present invention.
FIG. 2 illustrates an alternate exploded, perspective view of the cushion sub-assembly of FIG. 1 ;
FIG. 3 a illustrates an axial cross-sectional view of the cushion sub-assembly of FIGS. 1 and 2 ;
FIG. 3 b illustrates a cross-sectional view of the cushion sub-assembly of FIGS. 1 and 2 , taken along line A-A in FIG. 3 a.
FIG. 4 illustrates a cross-sectional view of the cushion sub-assembly of a second embodiment of a cushion sub-assembly.
Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.
DESCRIPTION OF EMBODIMENTS
Referring to the drawings, the cushion sub-assembly is generally denoted by the reference numeral 10 . Cushion sub-assembly 10 has a main body 12 including an outer housing or casing member 14 , the casing member 14 having an outer cylindrical surface 16 and an inner cylindrical surface 18 , and which together with a bottom surface 20 and a back head 22 , form an inner closed chamber 24 .
The back head 22 includes a pin connection 26 in the usual form of a tapered threaded portion concentrically and integrally formed with the back head 22 . Disposed within the main body 12 is a piston member 28 formed integrally with a cylindrical shaft 30 which projects downwardly through a circular opening 32 in the bottom surface 20 , as well as through a circular opening 34 in a connecting piston seal plate 36 . Within a lower end 38 of the shaft 30 is formed a box connector 40 formed by the usual tapered threaded opening.
While the present description refers to the back head 22 and the outer housing 14 , it is to be appreciated that the sub-assembly cushion 10 need not be orientated in the position shown in the drawings. However, normally the pin connection 26 is connected directly to the output of the rotary drive of a drilling rig (not shown), this being referred to herein as the drive portion of the drill string. In such an arrangement, the box connector 40 is directly connected to the upper most section of the actual drill string, hereinafter referred to as the driven portion of the drill string.
Housed inside the chamber 24 are a number of components, including a plurality of elongated piston rods 42 , a lower vibration damper or shock pad 44 , and three upper vibration dampers or shock pads 46 , 48 and 50 , which are described in further detail below.
The piston member 28 is disposed within the casing member 14 , and has a top surface 52 and an outer cylindrical surface 54 which is of substantially the same diameter as the inner cylindrical surface 18 of casing member 14 , so as to be axially slidable within the casing member 14 . In the embodiment illustrated, the shaft 30 of the piston member 28 is integrally formed with the piston member, and is of smaller diameter so as to form a lower piston surface or shoulder 56 . The surface 20 defining the circular opening 32 through which the shaft 30 passes is provided with annular grooves which receive casing seals 58 and a casing wear strip 60 . The casing seals 58 are used to keep grease (not shown) in the chamber 24 . The piston seal plate 36 also includes a dust seal 92 which contacts the shaft 30 and thereby prevents dirt from entering inside the chamber 24 .
As described above, the cushion sub-assembly 10 includes a plurality of elongated piston rods 42 . The piston rods 42 are of a circular cross-section and are stepped down in diameter towards the upper and lower ends of the rods. The lower ends of the rods 42 are stepped down in diameter a first time to accommodate the lower shock pad 44 , and then again so as to be accommodated within the axially extending and correspondingly shaped bores 62 in the lower surface 20 of the casing member 14 . Likewise, the upper ends of the piston rods 42 are stepped down first to accommodate three shock pads 46 , 48 and 50 and to be received within axially extending grooves 64 formed in the back head 22 , and then again to receive rod seals or caps 66 , which are placed on the upper ends of the piston rods 42 to prevent movement thereof.
The piston rods 42 extend the full length of the chamber 24 , and run inside bores 68 which extend axially through the piston member 28 . The purpose of the piston rods 42 is to prevent relative rotation of the casing member 14 and piston member 28 , while permitting axial movement of the piston member 28 relative to the casing member 14 .
The fact that the piston rods 42 run inside the piston member 28 contributes to reduced vibration, as described in further detail below, but also ensures that the rods 42 and the piston member 28 are the only major components which require re-working/replacement when the cushion sub-assembly is at the end of its useful working life. Clearly, the refurbishment of the cushion sub-assembly 10 requires only the boring out of the piston member bores 68 , and replacing of the piston rods 42 with rods of larger diameter which correspond with the diameter of the newly formed bores 68 . The commercial benefits of using a cushion sub-assembly 10 which can be quickly, easily and inexpensively refurbished to a state that is suitable for re-use are clearly apparent.
The piston member 28 is hollow so as to define an internal passageway 70 axially therethrough, the passageway 70 extending through the shaft 30 of the piston as well so as to be in fluid communication with the interior of a driven portion of the drill string connected by way of the box connector 40 to the piston member. The pin connection 26 of the back head 22 also has an internal passageway 72 extending therethrough so as to communicate with the section of a drill string which forms the drive portion, normally the rotary drive (not shown), connected to casing 14 of the cushion sub-assembly 10 by way of the back head 22 .
A cylindrical sleeve member or air nozzle 74 has an upper end thereof disposed within a lower portion of the internal passageway 72 of the back head 22 and a lower end thereof disposed within an upper portion of the passageway 70 of the piston member 28 , the air nozzle 74 thus placing the internal passageway 72 in fluid communication with the internal passageway 70 . Accordingly fluid is free to flow through the cushion sub-assembly 10 from an upper driven member of the drill string to a lower driven member. The air nozzle 74 has a radially projecting annular flange 76 encircling its upper end. The flange 76 is retained against a shoulder 78 formed within an enlarged lower portion of the internal passageway 72 in the back head 22 by way of a retaining ring 80 .
Two o-rings 82 are located above the flange 76 so to isolate the cylinder chamber 24 from the internal passageway 72 . At the upper end of the internal passageway 70 in the piston member there is also provided a plurality of annular grooves, the upper one of which contains a piston wear strip 84 , and the others being piston seals 86 , to isolate the cylinder chamber 24 from the internal passageway 72 .
Located in the upper end of cylinder chamber 24 are three annular shaped piston shock pads 46 , 48 and 50 , which prevent metal to metal contact between the top surface 52 of the piston member 28 and the back head 22 . Located in the lower end of cylinder chamber 24 is a single annular shaped piston shock pad 44 , which sits above surface 20 of the casing member 14 and prevents metal to metal contact between the shoulder 56 of the piston member 28 and the surface 20 . The shock pads serve to cushion axial vibration and may be formed of an elastomeric type material, such as a polyurethane.
The three upper shock pads have different grade strengths. The lowest pad 46 is thick but has the lowest strength of the three pads, the middle pad 48 is of the same thickness but with increased strength, and the top pad 50 is the thinnest but the strongest. The pad at the lower end of the chamber 24 is of the same thickness as pad 46 and 48 but of the same strength as pad 50 . It has been found that in arranging the shock pads in layers of different size and strength as illustrated, as well as having the piston rods 42 run inside the piston member 28 as described above, allows axial vibration to be significantly decreased because force is absorbed across all three pads, and the final pad being the strongest ensures that minimal vibration is carried up through to the rotary head. The rod seals 66 , in cushioning the upper ends of the piston rods 42 , may also provide a form of torsional vibration damping.
As the piston member 28 approaches its lower extreme position, its downward movement relative to the casing member 14 is cushioned by the lower shock pad 44 and then as it approaches its higher extreme position, its upward movement relative to the casing member 14 is cushioned by the upper shock pads 46 , 48 and 50 . It can be seen, therefore, that the piston member 28 has relatively free or floating movement within a major portion of its axial travel intermediate the lower surface of shock pad 46 and the upper surface of shock pad 44 , while being prevented from axial rotation relative to the casing member 14 by way of the piston rods 42 . The extent of movement of the piston member 28 is approximately 100 mm.
The back head 22 and piston seal cap 36 can be attached to the casing member 14 using any suitable connection means such as threaded bolt connections. The same applies to the connection between the retaining ring 80 and air nozzle 74 . The reference numeral 90 is used in connection with all of the bolts used. It is to be understood however that the present invention is not intended to be limited to a particular type of connection means. Prior to bolting, the chamber 24 is filled with grease (not shown), and where re-greasing is required, there is also provided a plug 88 extending through the side wall of casing member 14 .
FIG. 4 illustrates a second embodiment of the cushion sub-assembly 10 . In this embodiment, there is a single annular shaped piston shock pad 94 as an alternative to three annular shaped piston shock pads 46 , 48 and 50 illustrated in previous embodiments. Also, in this embodiment, the plug 88 (not shown on FIG. 4 ) is disposed towards an upper section of the cushion sub-assembly 10 . Furthermore, in this embodiment, piston wear strip 84 is disposed below the top surface 52 of the piston member 28 .
The cushion sub-assembly 10 provides a means of significantly reducing vibrations resulting from downhole hammer type drilling, which are typically carried up through to the rotary head and which may otherwise cause significant damage. During testing of various embodiments, the cushion sub-assembly 10 has been found to decrease axial vibrations by a factor of three to four.
The invention further provides a cushion sub-assembly that is of a more efficient design than previously known sub-assemblies in that there are fewer parts, and the arrangement of parts, for example the fact that the piston rods 42 run inside the piston member 28 , means that fewer parts (such as the casing member 14 for example) require replacement. The design allows those parts which do become worn through use, to be easily refurbished or replaced within minimal time and with minimal expense.
Further advantages and improvements may be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. | A cushion sub-assembly ( 10 ) for connection to a drill string to absorb vibrations in the drill string, the cushion sub-assembly ( 10 ) including a main body ( 12 ) defining a chamber therein ( 24 ), a piston member ( 28 ) disposed within the chamber ( 24 ) capable of axial movement at least partially within the chamber ( 24 ) between a first and second position, at least one axially extending piston rod ( 42 ) disposed inside a respective axial bore of the piston member ( 28 ), the at least one piston rod ( 42 ) preventing relative rotation between the piston member ( 28 ) and the main body ( 12 ) while permitting axial movement of the piston member ( 28 ) between the first and second positions, and a vibration absorbing means ( 44, 46, 48, 50 ) at opposite ends of the chamber ( 24 ) for engagement by the piston member ( 28 ) when in either of the first or second positions for absorbing axial vibrations, the configuration of the at least one piston rod ( 42 ) inside the piston member ( 28 ), and engagement of the piston member ( 28 ) with the vibration absorbing means ( 44, 46, 48, 50 ) serving to minimize transmission of axial vibrations between the piston member ( 28 ) and the main body ( 12 ). | 4 |
PRIOR APPLICATIONS
This application is a continuation-in-part of provisional patent application No. 61/183,969, filed Jun. 4, 2009.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to video games. More particularly, the present invention relates to a game apparatus and game control method for controlling magical ability, prowess and power of a player character in a video game, which constantly provides a representative indicator of such magical abilities, prowess and/or power on a video display apparatus, and wherein an unlimited amount of said abilities is constantly available to the game player, and therefore the player character. However, these unlimited amounts of abilities can inflict a detrimental effect on the player character based upon the current state of being for any given character thereby requiring that the game player balance these abilities for his player character based upon a desired or necessary course of action or need to achieve a specific result, which benefits the game player of the video game, regardless of whether the player character survives in a virtual basis on the video display apparatus.
2. Description of the Prior Art
Video games for home use were first introduced in the early 1970's. Throughout the 1970's and 1980's the industry saw substantial and profitable growth. However, in the late to mid 1990's and through-out the first decade of the twenty-first century the industry has seen incredible growth that has made the it into a $10 billion industry, which rivals the motion picture industry as the most profitable entertainment industry in the world.
Part of this explosive growth has been a result from moving away from PC-based games to those played on gaming consoles such as Microsoft's X-Box™ and Sony's Playstation™ as well as online gaming over the Internet. However, another large part of this expansive growth has been due to the realistic and near-virtual abilities of the games and the processing power of the gaming consoles. Even though many of the games employ abilities, which defy the laws of physics and actual human capabilities, the realistic graphics and visual effects continue to awe “gamers” to play these video games to ever reaching levels.
Many well known video games are based upon real characters from history, while others emanate from mythology, while still others are created as fanciful characters by gaming industry developers and story writers. In an attempt to make a game more appealing to gamers, new and innovative attributes of each game are constantly invented. These include the powers and abilities of both the non-player characters (also known as an “NPC”) as well as the player characters of the gamer (also known as the “avatar”).
Avatars are a video game player's representation of himself (an alter ego) in the form of a three-dimensional model in a virtual world. Avatars are the basis of computer role playing games (called a “CRPG” or more often just “RPG”), wherein the computer player defines his or her actions based upon decisions made from a selection of pre-defined choices within the game programmed by the game developers. However, as can be understood, the course of the game and the eventual goal or outcome of the game is essentially incalculable due to the fact that different computer game players will instinctively make different choices (also known as “character advancement”). Further, since the avatar is in a virtual world, the abilities of such can be endless and are only limited by the expansive imagination of today's video game programmers.
One well known example of a popular RPG wherein an avatar is used is the game entitled Grand Theft Auto™. In this game, the avatar more closely resembles the abilities of an actual real life person and does not possess powers that defy the known laws of physics. The avatar steals cars, using violence, and is constantly being chased by the police. However, in other games, wherein the laws of physics are defied, an avatar may have the ability to obtain magical power and to cast magical spells within a game as it progresses for the purpose of achieving some desired result. One such example is the game Oblivion™, which takes place in a mythological world full of demons and monsters in conjunction with human beings and various hybrids thereof. In games such as this, the types of magic that can be obtained and the spells that can be cast seem endless as new and innovative ideas continue to emerge year after year within the video gaming industry. Regardless of the magic obtained or sought after, almost all video games of this genre use a scenario wherein the game player must achieve some task. This may be to travel through some distance in real time, escape from a particular location, defeat an enemy or attacker, find some hidden box, chest or treasure or take away some power from another character, whether that other character is another avatar within a multiplayer game environment or whether he is a non-player character programmed within the game.
These magical abilities are typically stored by the avatar for later use, when needed. The use of such magical powers may require the casting of a spell by mixing together different ingredients obtained within the game or from merely using a device or an inherent power that is now part of the avatar's character. Examples of magical powers include, but are not limited to, making oneself indestructible against an enemy's power or some encountered natural environmental condition (i.e., freezing cold temperatures), making oneself invisible, throwing fire or other similar destructive natural occurring forces, moving objects out of the way, tele-transportation of oneself, shape shifting and temporary enhanced physical ability and stature.
A typical example of how magical abilities, along with health and fatigue, are represented in a video game power control program can be seen in FIGS. 1 and 2 , appropriately labeled as “Prior Art.” As seen in FIG. 1 , an avatar is represented having some amount of Health, Fatigue and Magical Abilities/Powers by horizontal bars, wherein the fully hatched bar of this black and white drawing represents “full” Health, Fatigue and Magical Abilities/Powers. In a game, these would be most often represented by color or shades of darkness to indicate a contrast so that it can be seen when a given level drops. In Prior Art FIG. 2 , it can now been seen that the avatar is in combat with an enemy, wherein the avatar is sustaining injury and he is also using energy to fight. Therefore, his level of Health and Fatigue are dropping, and the hatching of this black and white drawing is now representing depleted levels of Health and Fatigue. Furthermore, the avatar is tapping into his reserve of Magical Abilities/Powers by casting magic against his enemy in hopes of defeating him. This too is depleting his level of Magical Abilities/Powers as can be seen in the drop along the respective horizontal bar. Again, in the video game on a display screen, these would not be represented by hatching but instead by color or contrast to indicate that these three attributes are dropping.
In these prior art games, it can be seen that these reserve levels are being depleted along a line through the use of a simple liner scale (i.e., the difference between two values is perceived on the basis of the difference in actual values). For example, in the prior art, use of a specific magical spell depletes his Magical Abilities/Powers by a certain pre-programmed set amount decided by the game programmers and developers. Since there is only a set of amount of magic that can be used, the avatar must be careful not to use all of his magical abilities since he may need more in his next enemy encounter. If he uses all of his magical abilities, but is successful in defeating this particular enemy before his health is fully depleted, he will need to scour for more magic to horde and he must do so with traditional combat abilities (i.e., in this example, with his sword alone). The linear scale approach to magical ability depletion, along with the limited amounts of magical power that is available and the need to find more magic before it can be used, is a serious limitation in all prior art video games and action power control programs. Improvement is clearly needed to enhance the video game experiences when operated in a virtual world on a computer or gaming console and displayed on a video screen that is connected thereto.
SUMMARY OF THE INVENTION
I have invented an improved method for controlling and representing magical ability and power of a player character, in an action power control program used on a computer or video game console and controlled by a computing input device. In my method and with my input device, unlimited magical power can be channeled to the player character at any time by use of a gaming console game controller (for example) or any other known computer input device, much like a spigot can be an unlimited source of water. There is no scouring or searching within the virtual world of the video game in my method, which requires the game player to find and horde magical abilities for his player character to have the use of magic. In my method, magic is always available, simply by engaging the spigot through affecting pressure on any one of numerous buttons available on a computing input device, such as a game console controller. However, depending on the game player's character at any given point within the action power control program, the initiation or use of excessive channeled magic to the game character (i.e., turning the spigot to wide open) can cause a detrimental effect to the game character, which then requires the game player to return to a starting point in the action power control program.
Representation of the unlimited magical power and the effects it has on a player character within the action power control program can take many forms. In one embodiment, a computerized graphic on a display screen interfacing with the computer or gaming console that is operating the action power control program represents the unlimited magical power with a flame-like graphic (similar to a “roaring blue” Bunsen burner flame), wherein the inner richly colored blue flame is the magic being channeled to the player character and the outer flame areas of lesser blue color is the amount of effect (damage) that the channeled magic is having on body of the player character utilizing the magic (see FIG. 3 ). The relationship between these two forces affects how long a player can survive with any given level of magic being channeled and is measured by a level of vitality. The stronger the player character, the more channeled magic he can utilize with lesser effects (i.e., “burn-off”) to his body and therefore lesser effects to his vitality (i.e., he can live longer).
In the preferred embodiment if the present invention, employing a first person perspective and utilizing a HUD (a “head-up display”), regardless of the player character's vitality or his capability of channeled magic, there is a 30 second window of opportunity, although other time limits can be employed, to push the unlimited magical power to its highest level for that particular character before he dies due to the depletion of his vitality. It is therefore seen that the loss of vitality can cause death, but it is non-linear, as compared to health as is represented and used to control a player character in a prior art action power control program. Instead, the present invention uses an algorithmic representation based upon player character magical abilities, vitality and current channeled magic through the use of a computing input device. For avoidance of doubt, the use of an algorithmic scale permits a change between two values to be perceived on the basis of the ratio of the two values and not the difference there between.
In an alternate embodiment, employing a third person perspective for the player's avatar, the magical spell spigot is represented on the actual physical body of the game player's avatar (see FIGS. 9 and 10 ) as a glow emanating from the back of the neck of the player character, which then radiates through the body like veins, although other “on-person” representations can be employed.
Regardless of whether utilizing the preferred or any alternate embodiment of the present invention, power ratings are assigned to the various game characters, of which the avatar is capable of inhabiting or “taking over.” The numerical values have ranges and represent a relative power value that is not known to the game player as a numerical number, but instead something he learns from trial and error, which is meant to become intuitive, through use of the magical spell spigot.
It is therefore a first object of the present invention to provide a game apparatus for controlling and representing magical ability and power of a player character, in an action power control program.
It is a further object of the present invention to provide a game control method for controlling and representing magical ability and power of a player character, in an action power control program, represented on a display screen in a virtual basis.
It is yet a further object of the present invention to provide a computer-readable storage medium including computer program code for storing an action power control program for controlling and representing magical ability and power of a player character in the action power control program.
It is a even a further object of the present invention to provide a computer program product for controlling and representing magical ability and power of a player character in the action power control program through the use of a computing input device.
It is yet even a further object of the present invention to provide a game control method for controlling and representing magical ability and power of a player character, in an action power control program, represented on a display screen in a virtual basis, wherein the magical ability is graphically displayed on the display screen in the form of Bunsen burner flame.
Still another object of the present invention is to provide for a magical ability representation that is a physical part of the avatar's body.
And still anther object of the present invention is to provide numerical value ranges to player character types that represent a relative power value that is not known to the game player as a numerical number, but instead something that he learns from trial and error by inhabiting a certain type of character and through the use of the magical spell spigot.
Yet another object of the present invention is to provide a game viewing experience for the game player's avatar from either the first or third person perspective.
These and other objects of the present invention will become apparent when taking into consideration both the brief description of the drawings and detail description of the preferred embodiment both sequentially set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description of the invention, contained herein below, may be better understood when accompanied by a brief description of the drawings, wherein:
FIG. 1 illustrates a typical prior art representation in a video game of certain abilities and attributes of a game player's avatar, including Health, Fatigue and Magical Abilities/Power;
FIG. 2 illustrates those same prior art represented video game avatar abilities and attributes, and how they are depleted by a linear function when the avatar is engaged in combat against an enemy;
FIG. 3 illustrates examples of game character types (i.e., avatars) in a video game utilizing the game control method for controlling and representing magical ability and power of a player character, in an action power control program of the present invention, wherein a represented quantity of unlimited magic can be channeled at anytime during said action power control program (represented by the smaller of the two “flame-like” shapes) to said character, in combination with representation of how much effect that quantity of channeled magic has on the character type (i.e., how much “burn-off” or damage to the avatar's body, represented by the larger of the two “flame-like” shapes) in relation to an avatar attribute of Vitality;
FIG. 4A illustrates a character encounter between an avatar and another character in a video game of the game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, of the present invention, wherein the game player's avatar's attributes of Magical Power, Health and Vitality are represented in a virtual environment on a display screen in defined quantities against the other character (NPC 1 ) having a defined quantity of Health and an obtainable quantity of Magical Power and Vitality that cannot be used by NPC 1 , but which can be taken by the avatar if he chooses to take-over (inhabit) the body of NPC 1 under certain conditions precedent;
FIG. 4B illustrates the same character encounter as that of FIG. 4A , but wherein the avatar has tapped into the unlimited source of Magical Power to a certain level that does not exceed his Magical Power abilities for casting a specific Magical Spell against NPC 1 , with further representation on how that Magical Spell affects the NPC 1 's Health and the avatar's Vitality (i.e., effect of depletion) by casting the specific Magical Spell;
FIG. 4C illustrates the same character encounter as that of FIGS. 4A and 4B , wherein the avatar continues to tap into the unlimited source of Magical Power to the same level, but still not exceeding his Magical Power abilities, for casting a Magical Spell against NPC 1 with further representation on how that Magical Spell finally affects the NPC 1 's Health to make him believe that he is about to die, which causes the NPC 1 Soul and Spirit to depart from his body and further how the avatar's Vitality is further effected by continuing to cast this specific Magical Spell to an almost critical level for the avatar;
FIG. 5A illustrates a discrete moment in time after the character encounter of FIGS. 4A-4C in a video game of the game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, of the present invention, wherein a second character encounter occurs, but wherein the avatar has taken-over the body of NPC 1 of the character encounter illustrated in FIGS. 4A-4C such that the avatar now possesses the new Magical Power abilities and Vitality obtained from NPC 1 , but also the NPC 1 health level at the time of the body take-over, and wherein further a second character encounter is occurring and the game player's avatar's new attributes of Magical Power, Health and Vitality are represented in a virtual environment on a display screen in defined quantities against a new and different character (NPC 2 ) having a defined quantity of Health and an obtainable quantity of Magical Power and Vitality that cannot be used by NPC 2 , but which can be used by the avatar if he chooses to take-over the body of NPC 2 under certain conditions precedent;
FIG. 5B illustrates the same character encounter as that of FIG. 5A , but wherein the avatar has tapped into the unlimited source of Magical Power to a certain higher level than before, but which does not exceed the avatar's new higher Magical Power abilities for casting a Magical Spell against NPC 2 and for making NPC 2 believe that he is about to die, which causes the NPC 2 Soul and Spirit to depart from his body, with further representation on how this particular Magical Spell affects (depletes) the avatar's new level of Vitality;
FIG. 6A illustrates a new discrete moment in time after the character encounter of FIGS. 5A-5B in a video game of the game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, of the present invention, wherein a third character encounter occurs, but wherein the avatar has taken-over the body of NPC 2 of the character encounter illustrated in FIGS. 5A-5B such that the avatar now possesses the new Magical Power abilities and Vitality obtained from NPC 2 along with the NPC 2 health level at the time of the body take-over, and further wherein the game player's avatar's new attributes of Magical Power, Health and Vitality are represented in a virtual environment on a display screen in defined quantities against two new and different opposing characters (NPC 3 ) and (NPC 4 ), each having their own defined quantities of Health and their own set of obtainable quantities of Magical Power and Vitality that cannot be used by either character, but which can be taken by the avatar if he chooses to take-over the body of one or the other of the two characters NPC 3 and NPC 4 under certain conditions precedent;
FIG. 6B illustrates the same character encounter as that of FIG. 6A , but wherein the avatar has tapped into the unlimited source of Magical Power to a certain new higher level than before, but which does not exceed the avatar's new higher Magical Power abilities, for casting a Magical Spell against NPC 4 that kills him, with further representation on how this particular Magical Spell affects (depletes) the avatar's newest level of Vitality;
FIG. 6C illustrates the same character encounter as that of FIGS. 6A-6B , with NPC 4 dead, and wherein the avatar has tapped into the unlimited source of Magical Power to a certain even new higher level than before, but which still does not exceed the avatar's newest level of Magical Power abilities, for casting a Magical Spell against NPC 3 , which makes NPC 3 believe that he is about to die, even though his Health has not been depleted (no damage to NPC 3 body) from its original level, but which causes the NPC 3 Soul and Spirit to depart from his body, with further representation on how this particular Magical Spell further affects (depletes) the avatar's newest level of Vitality, aggregated by casting two different Magical Spells for killing NPC 4 and for making NPC 3 believe that his death was imminent;
FIG. 7A illustrates a new discrete moment in time after the character encounter of FIGS. 6A-6C in a video game of the game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, of the present invention, wherein a fourth character encounter occurs, and wherein the avatar has taken-over the body of NPC 3 of the character encounter illustrated in FIGS. 6A-6C such that the avatar now possesses yet a newer and higher level of Magical Power abilities and Vitality obtained from NPC 3 , along with the full health of NPC 3 , which still existed at the time of the body take-over by the avatar, and further wherein the game player's avatar's newest attributes of Magical Power, Health and Vitality are represented in a virtual environment on a display screen in defined quantities against three opposing characters (NPC 5 ), (NPC 6 ) and (NPC 7 ), each of the three encountered characters having their own defined quantities of Health and their own set of obtainable quantities of Magical Power and Vitality that cannot be used by any one of them, but which can be taken by the avatar if he chooses to take-over the body of any of the three characters NPC 5 , NPC 6 and NPC 7 under certain conditions precedent;
FIG. 7B illustrates the same character encounter as that of FIG. 7A , but wherein the avatar has tapped into the unlimited source of Magical Power to a certain yet even new higher level than before, but which does not exceed the avatar's newest higher level of Magical Power abilities, for casting a first Magical Spell against NPC 5 that kills him instantly by ripping his skeleton from his body and thereby creating an armor of bones for use by the avatar for protection against attack, with further representation on how this particular first Magical Spell affects (depletes) the avatar's newest level of Vitality;
FIG. 7C illustrates the same character encounter as that of FIGS. 7A-7B , with NPC 5 dead, and wherein the avatar has tapped into the unlimited source of Magical Power to a certain low level, which does not approach the avatar's newest higher level of Magical Power abilities, for casting a second Magical Spell against NPC 6 , which instantly kills him, with further representation on how this second Magical Spell further affects (depletes) the avatar's newest level of Vitality, aggregated by the killing of both NPC 5 and NPC 6 , but also how the avatar's health is not affected by attack from NPC 7 due to the protection of the bone armor;
FIG. 7D illustrates the same character encounter as that of FIGS. 7A-7C , with both NPC 5 and NPC 6 dead, and wherein the avatar has tapped into the unlimited source of Magical Power to another certain low level, one which does not approach the avatar's newest level of high Magical Power abilities, for casting a third Magical Spell against NPC 7 , which instantly kills him, along with further representation on how this third Magical Spell further affects (depletes) the avatar's newest level of Vitality, aggregated by the killing of all three characters NPC 5 , NPC 6 and NPC 7 ;
FIG. 8 illustrates an avatar possessing extremely high levels of Vitality and Magical Power, who can continually cast magic over long periods of time such that his Vitality is barely affected (a negligible amount) over one week, one month or even one year;
FIG. 9 illustrates an avatar in a video game utilizing the action power control program and method of the present invention wherein the a magical spell spigot has been opened and the effects of such use are shown affecting the body of said avatar;
FIG. 10 is a detail view of FIG. 9 ;
FIG. 11 illustrates a multitude of absolute power ratings that can be used with various types of player characters in a video game utilizing the action power control program and method of the present invention;
FIG. 12 is a detail view between two power ratings as seen in FIG. 11 , wherein the numerical values that are programmed for a given game character type are shown, but which are unknown to a game player of a video game utilizing the action power control program and method of the present invention; and
FIG. 13 illustrates Body Lifespan (Vitality) and Body Health of a game player's avatar in a video game utilizing the action power control program and method of the present invention, which are pieces of functionality relative to use of magic (Body Lifespan) and sustained attacks (Body Health), of which cannot be “refilled.”
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 , it can be seen that the prior art uses a method to represent various attributes, such as Health, Fatigue and Magical Abilities/Power, of a player character in a video game with horizontal bars that move in along a linear scale based upon the events occurring in such game. By way of example, FIGS. 1 and 2 show how a typical avatar in a prior art game having a full Health, Fatigue and Magical Abilities/Power losses some amount of these attributes as he fights an enemy. Each strike of the sword of the enemy against the unprotected body of the avatar will affect his Health and each swing of the sword by the avatar or other movement of his body will affect his Fatigue. Finally, the use of any Magical Abilities/Powers that the avatar has will deplete his finite reserve of such until it is empty.
The present invention differs significantly from the aforementioned prior art in a multitude of various ways. First, in the game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, of the present invention, there is no finite level of magic, which must be replenished and found by scourging through the scenes of the game. Instead, and referring to FIG. 3 , an infinite quantity of magic is always present and available for channeling to any given player character, represented along the “x” axis. In the present invention of a game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, it is possible for the player character to change bodies from the lowest of creatures (i.e., a rodent), to the highest of magical persons, such as an “Archmage” (a type of extremely powerful wizard, used within the context of a fantasy video game that utilizes the method of the present invention).
Therefore, with continuing reference to FIG. 3 , it can be seen that four types of player characters are represented (solely by way of example, as a multitude of other characters are employed) along the “y” axis; they include: a Wino, a Soldier, an Apprentice Mage and an Archmage. Each of these characters in the method of the present invention can utilize larger quantities of the unlimited quantity of magic that can be channeled, as compared to the “lesser character” below them. So, since some characters are not as strong as others, they do not have the same amount of Vitality, and therefore the quantity of channeled magic used can have a detrimental effect on those with lesser Vitality. By way of example, a Wino has less Vitality than a Soldier, who in turn has less Vitality than an Apprentice Mage, who in turn has less Vitality than an Archmage.
Again, with continuing reference to FIG. 3 , a representation of how magic can be shown on a display screen that interfaces with either a computer or game console wherein the method for controlling and representing magical ability and power of a player character, in an action power control program, is shown. In particular, it is shown how a quantity of unlimited magic can be channeled at anytime during said action power control program (represented by the smaller of the two “flame-like” shapes) to said character, in combination with representation of how much effect that quantity of channeled magic has on the character type (i.e., how much “burn-off” or damage to the avatar's body, represented by the larger of the two “flame-like” shapes) in relation to the avatar's attribute of Vitality. This can also be shown, as used in an alternate embodiment, to be part of the avatar's body, wherein a spigot of unlimited magical can be tapped into. What is most important to understand from FIG. 3 is that the use of just a little bit of magic, say for example in a Wino, has a large and detrimental effect on his Vitality, which could lead to a quick death for the Wino. In contrast though, the use of a large amount of magic by an Archmage, even for long periods of time, can have very little, and in some cases almost non-existent, effect on his Vitality, permitting him to continuingly tap into the spigot and cast magic at will.
Referring now to FIGS. 4A-4C , it is shown how the method of controlling the magical power is carried out in a video game of the game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program, of the present invention. In particular, a character encounter occurs between an avatar and another character, wherein the game player's avatar's attributes of Magical Power, Health and Vitality are represented in a virtual environment on a display screen in defined quantities against the other character (NPC 1 ) having a defined quantity of Health and an obtainable quantity of Magical Power and Vitality that cannot be used by NPC 1 , but which can be taken by the avatar if he chooses to take-over (inhabit) the body of NPC 1 under certain conditions precedent. In this scenario, the avatar has a Magical Power ability of 25, a Health of 40 and a Vitality of 1,500. However, a Magical Power ability of 25 does not allow the avatar to channel large quantities of magic and in fact any magical spell that he uses by opening the spigot will more than likely deplete his Vitality quite quickly. In the preferred embodiment, utilizing the maximum amount of Magical Power (i.e., 25), will only provide the avatar with 30 seconds of life span to accomplish his task of killing or disabling his opponent NPC 1 before he dies and suffers whatever penalty that might entail. However, in FIGS. 4B and 4C , it can be seen that tapping into the spigot at about ⅘ ths of his capability (i.e., 20 of 25), he is able to defeat NPC 1 by making him think that NPC 1 is going to die, which causes his soul and spirit to depart, whereby the avatar can then jump into (i.e., inhabit) his body and take on the new levels of Magical Power abilities and Vitality of 100/2000, respectively. However, as shown in FIG. 5A , the avatar, now inhabiting NPC 1 also takes the current state of health of only 15 of a maximum of 30 while experiencing the next and new character encounter.
With reference now to FIG. 5B , the avatar has tapped into the unlimited source of Magical Power (the spigot) to a certain higher level than before (60 of 100), which does not exceed the avatar's new higher Magical Power abilities for casting a Magical Spell against NPC 2 and for making NPC 2 believe that he is about to die, which causes the NPC 2 Soul and Spirit to depart from his body. The effects on his body though can be seen as his Vitality drops from 2000 to 1,500. Notwithstanding, the avatar again jumps to a new body, that of NPC 2 and gains yet even a higher amount of Magical Power abilities and Vitality (250/5000, respectively). Again however, the avatar is forced to except the current state of health, which in this example, is 40 of 50.
Referring now to FIGS. 6A-6C , a new encounter occurs wherein the avatar, having taken-over the body of NPC 2 from the previous encounter, now possesses the new Magical Power abilities and Vitality (250/500, respectively) along with the NPC 2 health level at 40 of 50. The avatar encounters two opposing characters (NPC 3 ) and (NPC 4 ), each having their own defined quantities of Health and their own set of obtainable quantities of Magical Power abilities and Vitality that cannot be used by either character, but which can be taken by the avatar if he chooses to take-over the body of one or the other of the two characters NPC 3 and NPC 4 . In FIG. 6B it shows that the avatar has opened the spigot of Magical Power to a certain new higher level than before (150 of 250), but which does not exceed the avatar's new higher Magical Power abilities, for casting a Magical Spell against NPC 4 that kills him. The depletion of his Vitality is also shown as dropping from 5000 to 4000. In FIG. 6C , it shows the same character encounter as that of FIGS. 6A-6B , with NPC 4 dead, and wherein the avatar has tapped into the spigot of Magical Power to a certain even new higher level than before (225 of 250), which still does not exceed the avatar's newest level of Magical Power abilities, for casting a Magical Spell against NPC 3 , which makes NPC 3 believe that he is about to die, even though his Health has not been depleted (no damage to NPC 3 body) from its original level. This causes the NPC 3 Soul and Spirit to depart from his body, but the Vitality of the avatar is depleted further down to 2000 from 5000.
Referring to FIGS. 7A-7D , yet another new encounter occurs for the avatar, having taken-over the body of NPC 3 from the previous encounter, he now possesses the new Magical Power abilities and Vitality (1,000/15,000, respectively) along with the NPC 3 health level at 50 of 50, since no damage to the NPC 3 body had occurred. The avatar encounters three opposing characters (NPC 5 ), (NPC 6 ) and (NPC 7 ) each having their own defined quantities of Health and their own set of obtainable quantities of Magical Power and Vitality that cannot be used by any of the non-player characters, but which can be taken by the avatar if he chooses to take-over the body of any one or the three encountered characters. In FIG. 7B it shows that the avatar has opened the spigot of Magical Power to a certain new higher level than before (600 of 1,000), but which does not exceed the avatar's new higher Magical Power abilities, for casting a Magical Spell against NPC 5 that kills him and in the process rips his skeleton from his body for use as Bone Armor to protect the avatar against the other two encountered characters. However, there has been some significant level of depletion to the avatar's Vitality because of the opening of the spigot to such a large level or relative percentage.
Thereafter though, as shown in FIG. 7C , the avatar, with his Bone Armor in place, taps into the spigot of Magical Power to a fairly low level (75 of 1,000), which is more than adequate for casting a Magical Spell against NPC 3 , which kills him, but which depletes the avatar's Vitality by very little (only down to 10,900 from the previous level of 11,000). Then, as shown in FIG. 7D , the avatar directs his attention to NPC 7 and again taps into the spigot of Magical Power to a fairly low level (100 of 1,000) to quickly kill NPC 7 , which also has very little effect on the avatar's Vitality (down to 10,750 from the previous amount of 10,900).
Referring now to FIG. 8 , this diagram illustrates that in the method of the present invention that an avatar possessing extremely high levels of Vitality (100,000) and Magical Power abilities (10,000), can continually cast relatively effective (albeit a trickle as compared to the levels he could cast) magic over long periods of time while barely affecting his Vitality (a negligible level, at best) over one week (depleted only by 100 when casting Magical Power at a level of 200), one month (depleted only by 400 when casting the same Magical Power) or even one year (depleted only by 4,800 when again casting the same Magical Power).
Referring to FIGS. 9 and 10 , an alternate embodiment of the representation of the avatar's magical powers and how they affect his body is shown (i.e., how it is displayed to the game player by a third party perspective view). In particular, a visual representation (like a glow), emanates from the back of the neck of the player character. The glow is almost completely invisible when the spigot is at a minimal setting. It then transitions to a large bright flare when completely open. The glow radiates outward like white glowing veins through the body. This method is used as a combination of factors through the player character and any follow cameras. On the game controller, or on any other computing input device, as the spigot opens the camera is affected by the use of shake (along with player controller rumble), motion blur and depth of field. All these elements combine to give the sense of power utilized when opening up the spigot for the third party perspective alternate embodiment.
The Spell Spigot is what the player uses in the video game utilizing the method of the present invention to determine the size and power rating of the spell that they can cast. The spigot is opened and closed by affecting pressure on any one of a number of different buttons on a typical game console controller or other computing input device. The Spell Spigot itself is limited by the body type that the player inhabits—either from a very lowly drunk (extremely limited) up to a highly powerful Archmage (full power). The Spell Spigot is also directly tied to the lifespan of the body as it drains the life force when a player casts a spell. The more that the spigot is open, the more powerful the spell becomes but also the faster the drain on the current body life force (leading to a shorter lifespan). Examples of such where illustrated in FIGS. 4A through 7D . It should be noted that in the preferred embodiment, visually the Spell Spigot will be accomplished with the use of 2D HUD (“head-up display”) elements for the player to decipher. Only in the alternate embodiment of the third person perspective will all the elements be imbedded in the playable character on the video display screen, as discussed above and as shown by way of example in FIGS. 9 and 10 .
Further to the Spell Spigot, it essentially has two functions: (1) the Size of the Effect (the visual effects); and (2) the Absolute Power Rating (the damage inflicted). The Spell Spigot has a Spigot Cap that limits how much the player may open the spigot which is determined by what type of body the player has chosen to inhabit. By way of example, a street dwelling drunk has a very low Spigot Cap while a Mage has a very high Spigot Cap.
Referring now to FIG. 11 , an example of Absolute Power Rating is shown, wherein regardless of the actual numerical value that will be implemented of true damage inflicted, the power rating is deterministic. Once a game player recognizes each type of body, they will then understand that a Drunk Type isn't as good as a Thief Type. In a preferred embodiment there are nine power rating levels. However, alternate embodiments permit a greater or lesser number of power rating levels if so needed to accommodate a greater or lesser number of game character body types. In the preferred embodiment of FIG. 11 , there are Drunks, Prostitutes, Thieves, General Population, Armed Guards, Warriors, Brutes, Mages and Master Mages.
The Size of the Effect used visually in the alternate embodiment of the third person perspective changes as the game player opens the spigot to higher levels. The actual look of the effect, or the effect itself, does not necessarily matter, as there will be many magical spells that work in the same manner and display the same size and type of effect.
Referring now to FIG. 12 , a Relative Power Value is established between each character type, which is the actual numbers that are used to calculate damage inflicted upon an opponent and damage received to the avatar. These numbers can include a multitude of varying ranges and are not visible to the game player in a video game utilizing the method of the present invention. FIG. 12 (400 to 490 points) is merely illustrative of one of a plurality of numerical ranges.
Referring to FIG. 13 , the Body Life Span (also known as Vitality) and the Body Health are both illustrated. The Relative Power Value used by the game player is directly connected to draining the magic power from the inhabited body's total amount of magic power. This type of magic power is referred to as the Lifespan and losing this Lifespan is referred to as the Body Drain. The body's actual health (from taking physical damage through physical attacks) is a separate piece of functionality. Neither of these two items can be refilled; once it is used up, it's gone. The player must find another body to inhabit to regain Body Life Span and Body Health. In the alternate embodiment third person perspective, as the Lifespan is drained from the body, it is represented to the game player by the game player's character's body deteriorating. The body starts by looking “normal” and upon draining, the body slowly morphs down to a mummified skeleton. When the body gets close to being destroyed, it begins to smoke and then eventually catches on fire. If the player empties out the Body Lifespan, the body is destroyed and the player suffers whatever penalty the game designers create, such as reverting to a lowering being with less power.
The deterioration effect, as described above, is also used in the first person perspective preferred embodiment. However, only those body parts that can be seen from such first person perspective show the effect.
Further, equivalent steps can be substituted for ones set forth herein to achieve the same results in the same way and in the same manner. | A game apparatus and game control method for controlling and representing magical ability and power of a player character, in an action power control program is provided. The game apparatus and game control method permits the accessing of an unlimited level of magical power available to the player character by affecting a control button on the input device, which then allows for a determination to be made on a proper amount of the unlimited level of magical power based upon the player character's known abilities and vitality to be used, which then in turn permits utilization of said proper amount of the unlimited level of magical power against at least one other character within the video game to obtain a desired result against said at least one other character before a detrimental effect causes a penalty to the player character. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 10/888,195, filed Jul. 8, 2004, which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to integrated circuit memories. More particularly, this invention relates to the timing of data and clock signals of read operations in dynamic random access memories (DRAMs).
[0003] A DRAM is a form of semiconductor random access memory (RAM) commonly used as main memory in computers and other electronic systems. DRAMs store information in arrays of integrated circuits that include capacitors. High speed DRAMs, known as synchronous DRAMs (SDRAMs), use clocks to synchronize control and data signal transfers.
[0004] SDRAMs often transmit a clock signal along with the data produced from a read request. The clock signal is used by the receiving circuitry to determine when to sample the incoming data. In order to ensure accurate sampling, the data and output clock signals must satisfy certain timing specifications. Two important specifications are t_first and t_last.
[0005] The t_first specification defines the time between an output clock edge and the first bit transition on the data bus. This value is restricted to a range greater than a certain value, where the value depends on the size of the output clock period (t_clk). In a double data rate (DDR) system, where data transitions occur on both the rising and falling edges of the output clock, the optimal sampling time is the midpoint between two consecutive clock edges. Therefore, meeting the t_first specification ensures that a data transition occurs sufficiently after a first optimal sampling time.
[0006] In contrast, the t_last specification defines the time between an output clock edge and the last bit transition on the data bus. This value is usually restricted to a certain fixed range, e.g., less than 300 picoseconds. Meeting the t_last specification ensures that a data transition occurs sufficiently before a second optimal sampling time.
[0007] Assuming a DDR SDRAM system, the ideal timing scenario would have data transitions perfectly time-aligned with the output clock edges. In this ideal case, t_first would be t_clk/2 and t_last would be 0. If the data transitions occurred sufficiently after their corresponding clock edges, the t_first specification would be met, but the t_last specification might be violated. On the other hand, if the data transitions occurred sufficiently before their corresponding clock edges, the t_last specification would be met, but the t_first specification might be violated. Therefore, in a real-world system where some amount of skew is inevitable, meeting both specifications typically involves a tradeoff.
[0008] A problem arises when the output clock frequency is increased. As the clock period becomes shorter, meeting the t_first and t_last specifications becomes more difficult. In particular, the physical delay associated with outputting data from an array, referred to as t_delay, often becomes a limiting factor.
[0009] Normally, there is a certain latency, referred to as t_lat, involved in memory read operations. t_lat is defined as the amount of time between the start of a read instruction and the first valid edge of the output clock. Typically, t_lat is a certain multiple of the clock period, such as 2*t_clk.
[0010] Ideally, t_delay should be less than t_lat, so the outgoing data is latched until the first output clock edge. At that edge, the data is output onto the final data bus, resulting in substantially simultaneous signal transitions. However, if t_delay is greater than t_lat, as can happen when t_clk is very short, the data will be output as soon as it is ready, which can be skewed from the output clock edge by a significant amount. When that happens, it is quite possible to violate either the t_first or the t_last specification, or even both.
[0011] In view of the foregoing, it would be desirable to align an output clock with associated data when t_delay is greater than t_lat in order to ensure more reliable compliance with timing specifications. This permits more robust data retrieval and contributes to overall system reliability.
SUMMARY OF THE INVENTION
[0012] In accordance with this invention, circuitry and methods are provided that align an output clock with associated data when t_delay is greater than t_lat. In an exemplary embodiment of the invention, a circuit is introduced into the output clock path. This circuit is designed to track t_delay and introduce a matching delay into the output clock path when needed. This forces the output clock to transition at the same time as the outgoing data.
[0013] In many known memory devices, t_delay is caused partly by analog sense amplifier circuitry, which amplifies small voltage signals to comply with power source voltage levels. Tracking circuits of the invention may comprise similar sense amplifier circuitry in order to provide a matching delay.
[0014] The invention therefore advantageously tracks the value of t_delay and introduces a corresponding delay into the output clock path when appropriate. This adjustment improves system reliability by facilitating accurate data retrieval from the SDRAM.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
[0016] FIG. 1 is a block diagram of a typical SDRAM architecture;
[0017] FIG. 2 is a timing diagram illustrating various timing parameters of the SDRAM of FIG. 1 ;
[0018] FIG. 3 is a timing diagram illustrating a typical read operation;
[0019] FIG. 4 is a timing diagram illustrating a faulty read operation with a short clock period;
[0020] FIG. 5 is a block diagram of an illustrative SDRAM architecture in accordance with the invention;
[0021] FIG. 6 is a block diagram of another illustrative SDRAM architecture in accordance with the invention;
[0022] FIG. 7 is a timing diagram illustrating a corrected read operation in accordance with the invention;
[0023] FIG. 8 is a circuit diagram of a typical clock output buffer;
[0024] FIG. 9 is a timing diagram illustrating the operation of the clock output buffer of FIG. 8 ;
[0025] FIG. 10 is a circuit diagram of an illustrative t_delay model in accordance with the invention;
[0026] FIG. 11 is a circuit diagram of an illustrative clock output buffer in accordance with the invention;
[0027] FIG. 12 is a timing diagram illustrating operation of the invention with a relatively low clock frequency;
[0028] FIG. 13 is a timing diagram illustrating operation of the invention with a relatively high clock frequency; and
[0029] FIG. 14 is a block diagram of a system that incorporates the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIG. 1 shows a typical SDRAM architecture. It comprises an SDRAM 102 and a memory controller 104 . SDRAM 102 includes a memory array 106 , read circuit 108 , and delay locked loop (DLL) 110 . Read circuit 108 and DLL 110 accept external clock signal CLK_IN. At each edge of CLK_IN, read circuit 108 examines the contents of incoming bus CMD, and determines whether a memory operation (e.g., a read or a write) is required. If so, it communicates the necessary information to memory array 106 for execution. This information can include, for example, a read command and a memory address. DLL 110 generates a clock signal with the same frequency as CLK_IN, whose phase is locked to that of CLK_IN.
[0031] If a read operation is requested by read circuit 108 , memory array 106 will send the appropriate data to data sense amp 112 . A word of data can include any number of bits, such as 4, 8, 16, or 32. The embodiment shown in FIG. 1 uses a 4-bit data bus. Data sense amp 112 amplifies the received data to a suitable voltage level, usually determined by the power supply voltage. Thereafter, the amplified data is transmitted to data output buffer 114 , which stores the data in a memory element, such as a latch. When data output buffer 114 receives a valid clock transition from DLL 110 , it sends the data to memory controller 104 by way of signal DATA. When a read operation is requested by read circuit 108 , clock output buffer 116 transmits signal CLK_OUT to memory controller 104 . Controller 104 uses CLK_OUT to determine when to sample data values from signal DATA. Transitions of signal CLK_OUT are determined by the output of DLL 110 .
[0032] FIG. 2 shows several signals relevant to the invention. CLK_IN is the external clock transmitted to SDRAM chip 102 . CLK_OUT is the output of clock output buffer 116 . As shown, CLK_OUT transitions at substantially the same times as signal CLK_IN. DATA[3] through DATA[0] are the four bits transmitted through data output buffer 114 . Assuming a DDR system, DATA[3] through DATA[0] will transition at both rising and falling clock edges. In the example shown, DATA[3] tends to be the first bit signal to transition in a given cycle, while DATA[0] is the last to transition.
[0033] The waveforms illustrate several timing parameters relevant to the invention. For example, t_clk is the period of one cycle of CLK_IN, and equivalently, one cycle of CLK_OUT. t_first is the time measured from an edge of CLK_OUT to the first DATA transition corresponding to that edge. As shown, the first transition occurs on signal DATA[3]. If the first DATA transition is before the relevant edge of CLK_OUT, then t_first will have a negative value. In contrast, t_last is the time measured from an edge of CLK_OUT to the last DATA transition corresponding to that edge. In this example, the last transition occurs on DATA[0]. If the last DATA transition is before the relevant edge of CLK_OUT, then t_last will have a negative value.
[0034] The optimal time for memory controller 104 to sample the bus DATA is halfway between consecutive edges of CLK_OUT, for instance at times 202 and 204 . Because it is desirable for the DATA signals to be as stable as possible around these sampling times, restrictions are placed on t_first and t_last to ensure data signal integrity.
[0035] The time t_first is usually specified as being greater than a certain value, where the value depends on t_clk. Satisfying this specification ensures that there are no DATA transitions immediately after DATA is sampled, such as at time 202 . On the other hand, t_last is usually specified as being less than a certain fixed value, which is independent of t_clk. Satisfying this specification ensures that there are no DATA transitions immediately before DATA is sampled, such as at time 204 .
[0036] These two specifications, however, can result in conflicting conditions between CLK_OUT and DATA. For example, FIG. 2 shows all DATA transitions occurring at or slightly after the corresponding edge of CLK_OUT. In this case, the t_first specification is easily satisfied, and there is ample time between DATA sampling and the first subsequent DATA transition. However, the t_last specification may be violated if the DATA transitions drift too far after the CLK_OUT edge. Conversely, when DATA transitions occur slightly before the corresponding CLK_OUT edge, the t_last specification is easily satisfied, but the t_first specification may be violated. Therefore, a tradeoff is involved and care must be taken to satisfy both specifications by having the DATA transitions aligned with the CLK_OUT edges as precisely as possible.
[0037] FIG. 3 shows the timing of a typical read operation. Note that signal bus CMD is included, along with the signals shown in FIG. 2 . At time 302 , read circuit 108 observes a READ command on the CMD bus. At this time, both CLK_OUT and DATA have undefined values. A read request is transmitted to memory array 106 , which returns the appropriate data. The data is passed through data sense amp 112 and into data output buffer 114 , where it is latched. The time that elapses during this process is referred to as t_delay. As shown in FIG. 2 , t_delay has a value of less than 2*t_clk.
[0038] Similarly, there is a certain amount of latency involved in generating a suitable CLK_OUT transition. This latency, referred to as t_lat, is often a fixed multiple of t_clk. FIG. 3 illustrates a t_lat of 2*t_clk. Thus, two full clock cycles elapse from the detection of a read request (at time 302 ) to the first valid transition of CLK_OUT (at time 306 ). When this transition occurs, data output buffer 114 transmits its stored data to memory controller 104 , and the transitions of DATA are substantially aligned with the corresponding edge of CLK_OUT. Thus, as long as t_delay is less than t_lat, data output buffer 114 will be able to output DATA in response to receiving an edge of CLK_OUT.
[0039] FIG. 4 shows another read request, involving the same signals as FIG. 3 . However, in this case t_clk has been shortened, for example, to increase the rate of data throughput. As a result, t_lat is scaled down by a corresponding amount. In fact, t_lat is reduced to an amount shorter than t_delay, which does not vary with t_clk. Thus, data output buffer 114 receives the first valid edge of CLK_OUT before it receives any data, and opens its latch in response to that edge. As a result, DATA will transition as soon as the appropriate data arrives from the memory array without waiting for a clock edge. As shown in FIG. 4 , this results in a large skew between signals CLK_OUT and DATA. In particular, transitions of DATA occur very close to sampling time 402 , and both the t_first and the t_last specifications are violated. In other examples, the transitions of DATA might violate only one (or neither) of the t_first and t_last specifications. This unpredictability leads to reduced data integrity in the system.
[0040] FIG. 5 shows an SDRAM architecture in accordance with the invention. It comprises SDRAM 502 and memory controller 504 . SDRAM 502 includes memory array 506 , read circuit 508 , DLL 510 , data sense amp 512 , data output buffer 514 , and clock output buffer 516 . In addition, SDRAM 502 includes a t_delay model 518 in accordance with the invention, placed between read circuit 508 and clock output buffer 516 . This t_delay model introduces a delay comparable to that of memory array 506 and data sense amp 512 during a read transaction. In a preferred embodiment, t_delay model 518 includes data sense amp circuitry similar to that of data sense amp 512 .
[0041] FIG. 6 shows another SDRAM architecture in accordance with the invention. It comprises SDRAM 602 and memory controller 504 . SDRAM 602 includes memory array 506 , read circuit 508 , DLL 510 , data sense amp 512 , data output buffer 514 , clock output buffer 516 , and t_delay model 520 . In this embodiment, t_delay model 520 is placed between DLL 510 and clock output buffer 516 . Thus, signal CLK_OUT is shifted when appropriate by delaying the output of DLL 510 .
[0042] FIG. 7 illustrates the timing of a read operation that incorporates the invention. As in FIG. 4 , t_clk is sufficiently short so that t_lat is less than t_delay. Recall that without the invention, CLK_OUT would transition at time 704 , two clock periods after the start of the read operation at time 702 . However, because of the delay introduced by t_delay model 518 , CLK_OUT now produces its first edge at time 706 , substantially time-aligned with the first transition of DATA. Therefore, CLK_OUT and DATA are effectively synchronized with each other, and are not in danger of violating the t_first and t_last specifications. As a result, memory controller 504 can reliably receive data from the SDRAM.
[0043] Note that as a result of the invention, CLK_OUT may not be phase-aligned with CLK_IN. This shifting of CLK_OUT may be undesirable, and indeed may violate other timing specifications not discussed. However, because the signal CLK_OUT is used mainly as a reference for memory controller 504 , its relationship with CLK_IN is considered less important than its relationship with DATA.
[0044] FIG. 8 shows the structure of a typical clock output buffer 816 , which may be used as clock output buffer 116 of FIG. 1 . Clock output buffer 816 includes inverter 802 , NOR gate 804 , NAND gate 806 , NAND gate 808 , NOR gate 810 , inverter 812 , transmission gates 814 , 816 , 818 , and 820 , inverters 822 , 824 , 826 , 828 , 830 , 832 , 834 , and 836 , PMOS transistor 838 , and NMOS transistor 840 .
[0045] Inverters 802 and 812 accept input signal READ from read circuit 108 . Signal READ is usually a logical 1 when a read command has been issued and a logical 0 otherwise. Note that one input of respective gates 804 and 806 is tied to logical 0 (GND), while one input of respective gates 808 and 810 is tied to logical 1 (Vdd). These connections emulate corresponding connections in data output buffer 114 . The corresponding nodes in data output buffer 114 are connected to differential output signals of data sense amp 112 . These signals may be sent through parasitic routing before reaching data output buffer 114 .
[0046] Input signal DLL_RISE is applied to transmission gates 814 and 816 , rendering the gates active when DLL_RISE is high. DLL_RISE pulses high when the output of DLL 110 undergoes a rising transition. Similarly, input signal DLL_FALL is applied to transmission gates 818 and 820 and pulses high when the output of DLL 110 undergoes a falling transition.
[0047] When input READ is low, the output of NOR gate 804 is low, the output of NAND gate 806 is high, the output of NAND gate 808 is high, and the output of NOR gate 810 is low. Thus, when either DLL_RISE or DLL_FALL pulse high, activating the corresponding transmission gates, a logical 1 is applied to the gate of PMOS transistor 838 and a logical 0 is applied to the gate of NMOS transistor 840 . In other words, both transistors are rendered nonconductive, and output signal CLK_OUT takes on an undefined value.
[0048] When signal READ is high, the outputs of NOR gate 804 and NAND gate 806 are also high, while the outputs of NAND gate 808 and NOR gate 810 are both low. If DLL_RISE pulses high, activating transmission gates 814 and 816 , PMOS transistor 838 is rendered conductive and NMOS transistor 840 is rendered nonconductive, yielding a CLK_OUT value of logical 1. Inversely, if DLL_FALL pulses high, activating transmission gates 818 and 820 , PMOS transistor 838 is rendered nonconductive and NMOS transistor 840 is rendered conductive, yielding a CLK_OUT value of logical 0.
[0049] FIG. 9 is a timing diagram illustrating the operation of clock output buffer 816 when input signal READ is high. Signal CLK_IN is the external input clock, to which the output of DLL 110 is substantially phase-aligned. DLL_RISE pulses high when CLK_IN undergoes a rising transition and DLL_FALL pulses low when CLK_IN undergoes a falling transition. In one embodiment, the pulses of DLL_RISE and DLL_FALL have a width that is slightly less than ¼ t_clk (or equivalently, ½ of a clock pulse width). As shown, signals DLL_RISE and DLL_FALL generate a CLK_OUT signal with a frequency and phase that are substantially equal to those of signal CLK_IN.
[0050] FIG. 10 shows an exemplary embodiment of t_delay model 518 according to the invention. T_delay model 518 includes NAND gate 1002 , inverter 1004 , NAND gate 1006 , parasitic circuit 1008 , inverters 1010 and 1012 , transmission gate 1014 , and inverters 1016 and 1018 . Parasitic circuit 1008 may include capacitors, resistors, and the like, introducing a delay that is substantially equal to that undergone by signal DATA as it passes out of memory array 106 and through data sense amp 112 . In one embodiment, parasitic circuit 1008 may include sense amplification circuitry.
[0051] T_delay model 518 accepts input signals DSA_ENABLE, CLK_OUT_RESET, and DLL_LAT. Signal DSA_ENABLE corresponds to a signal that enables data sense amp 512 . Signal CLK_OUT_RESET pulses high in response to the end of a DLL_RISE pulse. Signal DLL_LAT corresponds to a signal used in the path of signal DATA, which is at least partly responsible for the latency t_lat described above. Note that inputs DSA_ENABLE and DLL_LAT are used to emulate timing constraints experienced by signal DATA. This effectively aligns CLK_OUT and DATA in accordance with the invention.
[0052] When input signal CLK_OUT_RESET pulses high, the output of NAND gate 1006 goes high. Thus, when DLL_LAT pulses high, output CLK_DELAYED takes on a value of logical 1. After the CLK_OUT_RESET pulse has passed, CLK_OUT_RESET returns to a low state. If DSA_ENABLE subsequently pulses low, rendering the output of NAND gate 1002 high, then both inputs of NAND gate 1006 are high, resulting in a gate output of low. When a DLL_LAT pulse is received, output CLK_DELAYED takes on a value of logical 0. Then, a high pulse on CLK_OUT_RESET may be used to pull the value of CLK_DELAYED high, while a low pulse on DSA_ENABLE may be used to pull the value of CLK_DELAYED low.
[0053] FIG. 11 shows the structure of an exemplary embodiment of clock output buffer 516 according to the invention. Clock output buffer 516 is substantially similar to clock output buffer 816 , and analogous circuit elements have reference numbers that differ by 400 . The main structural differences between the two circuits relate to the use of signal CLK_DELAYED. The input of NOR gate 1104 and the input of NAND gate 1106 that were previously tied to GND are now tied to signal CLK_DELAYED. Similarly, the input of NAND gate 1108 and the input of NOR gate 1110 that were previously tied to Vdd are also tied to signal CLK_DELAYED. All other connections are substantially identical between the two circuits.
[0054] As before, a READ value of logical 0 results in an undefined CLK_OUT value, given an appropriate pulse of DLL_RISE or DLL_FALL. However, now a READ value of logical 1 will yield one of two scenarios, depending on the value of CLK_DELAYED. If CLK_DELAYED is low, then the output of all four logic gates 1104 , 1106 , 1108 , and 1110 will be high. Thus, a pulse of DLL_RISE or DLL_FALL will result in a CLK_OUT value of logical 1. On the other hand, if CLK_DELAYED has a value of logical 1, all four logic gates 1104 , 1106 , 1108 , and 1110 will output a logical 0. In this second scenario, a pulse of DLL_RISE or DLL_FALL will result in a CLK_OUT value of logical 0. Thus, switching CLK_DELAYED to one logical value results in switching CLK_OUT to the opposite logical value.
[0055] FIG. 12 illustrates the operation of signals in FIGS. 10 and 11 with a relatively low CLK_IN frequency. As before, all pulses (e.g., of signals DSA_ENABLE, DLL_RISE, CLK_OUT_RESET, DLL_FALL, and DLL_LAT) preferably have a width of slightly less than ¼ t_clk (or equivalently, ½ of a clock pulse width). Also, recall that the output of DLL 510 is substantially aligned in frequency and phase with signal CLK_IN.
[0056] A rising edge of signal CLK_IN will generate a high pulse of signal DLL_RISE. The end of that pulse will generate a pulse of signal CLK_OUT_RESET which, as described above, results in a CLK_DELAYED value of logical 1. A rising edge of signal CLK_IN also generates a low pulse on signal DSA_ENABLE which, as described above, results in a CLK_DELAYED value of logical 0. Thus, signal CLK_DELAYED has a substantially similar frequency to signal CLK_IN, but is delayed in phase. Note that the end of a pulse of signal DLL_FALL will result in a pulse of DLL_LAT, which activates a transmission gate that drives the value of CLK_DELAYED, as described above.
[0057] In FIG. 12 , the frequency of CLK_IN is sufficiently low. Therefore, pulses of DLL_RISE (e.g., in time period 1202 ) will coincide with intervals in which CLK_DELAYED has a value of logical 0. As described above, this will result in a CLK_OUT value of logical 1. On the other hand, pulses of DLL_FALL (e.g., in time period 1204 ) will coincide with intervals in which CLK_DELAYED has a value of logical 1. As described above, this will result in a CLK_OUT value of logical 0. Since CLK_DELAYED holds its value throughout the duration of DLL_RISE and DLL_FALL pulses, signal CLK_OUT transitions in response to a rising edge of DLL_RISE or DLL_FALL. This behavior results in a CLK_OUT signal that is substantially phase-aligned with signal CLK_IN. In other words, if t_lat is greater than t_delay, as illustrated in FIG. 3 , then incorporating the invention advantageously does not alter the timing of CLK_OUT.
[0058] FIG. 13 illustrates a scenario where the frequency of CLK_IN is relatively high. (Some signals that were shown in FIG. 12 have been omitted for clarity.) In this case, a rising edge of DLL_RISE coincides with a high value of CLK_DELAYED. Therefore, CLK_OUT simply remains low as a result of the rising edge of the DLL_RISE pulse. However, sometime during the DLL_RISE pulse (e.g., during time period 1302 ), CLK_DELAYED switches from high to low, causing CLK_OUT to switch from low to high. Similarly, the rising edge of a DLL_FALL pulse coincides with a low value of CLK_DELAYED, allowing CLK_OUT to remain high. However, during the DLL_FALL pulse (e.g., during time period 1304 ), CLK_DELAYED switches from low to high, causing CLK_OUT to switch from high to low. Thus, in contrast to the scenario shown in FIG. 12 , the CLK_OUT transitions are not substantially aligned to rising edges of DLL_RISE and DLL_FALL. Rather, they are substantially aligned with transitions of CLK_DELAYED, which has been shifted from CLK_IN by a delay comparable to that of signal DATA. Therefore, as illustrated in FIG. 7 , in scenarios where t_lat is less than t_delay, the invention delays signal CLK_OUT by an amount that preferably substantially aligns the phases of CLK_OUT and DATA. In particular, the alignment occurs in a way that satisfies the t_first and t_last timing specifications, facilitating accurate data sampling at the memory controller.
[0059] Note that the embodiments described herein and shown are illustrative. The invention is applicable to other types of memories, devices, and circuits. For instance, t_delay can be created by a wide variety of circuitries other than those shown. One example involves the use of several processing stages, some coupled tightly to memory array 106 or 506 , and some applied mostly as post-processing modules. Post-processing can include encoding, decoding, or other data manipulation. Similarly, DLL 110 can be replaced by another synchronization circuit, such as a phase-locked loop (PLL) or ring counter delay. In addition, the number of bits in the signal bus DATA can be different than that shown, as can the number of cycles in t_lat. For instance, t_lat can be set to 2.5*t_clk, so that CLK_OUT would ideally produce its first transition at a falling edge of CLK_IN.
[0060] Other embodiments can also be used for t_delay model 518 and clock output buffer 516 . For instance, the transmission gates could be replaced by simple AND gates. Alternatively, the gates could be replaced with NAND gates while removing one inverter from the output chain of each gate. More generally, the polarity of many circuit elements could be reversed, along with the polarity of the incoming or outgoing signals if appropriate. Furthermore, instead of emulating the behavior of circuitry in the DATA path such as sense amp 512 , t_delay model 518 could simply introduce a delay through a series of buffers. It can also include more complex logic that would allow flexible adjustment of its timing behavior. In fact, the invention need not be applied in the context of an SDRAM transmitting data to a memory controller. It can be used in any situation where timing skew is introduced by shortened clock periods or other causes.
[0061] FIG. 14 shows a system that incorporates the invention. System 1400 includes a plurality of SDRAM chips 1402 , a processor 1401 , a memory controller 504 , input devices 1404 , output devices 1406 , and optional storage devices 1408 . SDRAM chips 1402 may be configured as either SDRAM 502 or 602 and may respectively include t_delay model 518 or t_delay model 520 . Either t_delay model aligns the data and clock signals transferred to memory controller 504 , shifting the clock signal when appropriate. Data and control signals are transferred between processor 1401 and memory controller 504 via bus 1410 . Similarly, data and control signals are transferred between memory controller 504 and SDRAM chips 1402 via bus 1412 . Input devices 1404 can include, for example, a keyboard, a mouse, a touch-pad display screen, or any other appropriate device that allows a user to enter information into system 1400 . Output devices 1406 can include, for example, a video display unit, a printer, or any other appropriate device capable of providing output data to a user. Note that input devices 1404 and output devices 1406 can alternatively be a single input/output device. Storage devices 1408 can include, for example, one or more disk or tape drives.
[0062] Thus it is seen that circuits and methods are provided for aligning an output clock with associated data when the output clock period is relatively short. One skilled in the art will appreciate that the invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims which follow. | Circuits and methods are provided for aligning data read from a memory with an output clock signal when the memory is operated at very high clock frequencies. To align data and clock signals when needed, delay is added to the output clock signal during the read operation. This alignment allows various timing specifications to be met when they would otherwise be violated, therefore improving data integrity in the system. | 6 |
BACKGROUND
[0001] The present invention relates to surface texturing to improve light trapping in solar cells, and more specifically, to low cost surface texturing of a Si containing substrate to form inverted pyramids using chemical etching and a low quality dielectric layer.
[0002] Texturing and anti-reflection coatings are commonly used to increase the efficiency of light absorption in solar cells. Upright pyramid formation on the surface of mono-crystalline silicon wafers is a standard technique for texturing the surface to maximize light absorption into a solar cell. It is well known that, by texturing a solar cell surface, photon utilization, light trapping or quantum efficiency can be improved by as much as 20% compared to a solar cell with a flat polished surface. Hemispherical reflectance of 10 to 13% has been reported from the upright pyramids formed by anisotropic chemical etching. The density of upright pyramids and their geometry both affect the light trapping efficiency. To achieve uniform and dense upright pyramids, isopropanol (IPA) can be added into alkaline etching solutions.
[0003] In order to achieve inverted pyramid patterns, photolithography followed by anisotropic etching is a standard sequence. Even if a more effective textured surface with less reflectance can be achieved by this method, the photolithography step adds to the cost of the process.
BRIEF SUMMARY OF THE INVENTION
[0004] In accordance with the present invention, a method for forming a textured surface on a Si containing substrate is described comprising forming a dielectric layer on the surface having a plurality of pinholes through the dielectric layer, anisotropic etching the surface through the pinholes to form inverted pyramid patterns and removing the dielectric layer. One embodiment of the invention provides a random distribution of inverted pyramid patterns having a hemispherical reflectance of less than 13%.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0005] These and other features, objects, and advantages of the present invention will become apparent upon consideration of the following detailed description of the invention when read in conjunction with the drawing in which:
[0006] FIG. 1 is a cross-section view of a structure having a Si layer or Si containing layer and a porous oxide and/or nitride dielectric layer with a high density of pinholes thereon.
[0007] FIG. 2 is a cross-section view of a structure after etching the upper surface of a Si layer or of a Si containing layer through a porous oxide and/or nitride dielectric layer.
[0008] FIG. 3 is a cross-section view of the structure of FIG. 2 after removing the porous oxide and/or nitride layer.
DETAILED DESCRIPTION
[0009] A method is described to form inverted pyramid patterns on a Si or Si containing surface with minimum process cost. The method offered does not require extensive etching of Si materials and a cost-inefficient photolithography step. The method for generating an inverted pyramid pattern on a Si surface is achieved through depositing one or more low quality porous dielectric layers on a Si surface followed by anisotropic etching of the Si surface with an alkaline solution where it penetrates the low quality porous dielectric layer or layers. A high density of pinholes having been formed in a low quality dielectric layer or layers is used as a mask for anisotropic etching. A random distribution of inverted pyramids are then formed in the Si or Si containing surface having a hemispherical reflectance of less than 13%.
[0010] Referring now to the drawing, FIGS. 1 through 3 illustrate the process flow to form inverted pyramid patterns on a Si or Si containing surface. FIG. 1 is a cross-section view of structure 10 having a substrate 12 which may, for example, comprise Si, a Si containing material, a glass, a metal or a polymer. A layer 14 of Si or a Si containing crystalline material is formed over substrate 12 . Layer 14 has an upper surface 15 which may be initially smooth. A smooth Si or Si-containing surface is a surface having a surface roughness of less than 1 nm root mean square (RMS). Surface 15 , if layer 14 is Si, may have a (100) crystal orientation.
[0011] A dielectric layer 18 is formed on crystalline silicon surface 15 of layer 14 . Dielectric layer 18 contains pores or pinholes 20 and functions as a mask layer for etching. Dielectric layer 18 may be low density, low quality, and/or porous and may be SiO 2 , SiN x or combinations of SiO 2 and SiN x . Typically, dielectric oxides or nitrides deposited using plasma enhanced chemical vapor deposition (PECVD) are less dense than those formed by other methods such as by thermal oxidation, atomic layer deposition (ALD), low pressure chemical vapor deposition (LPCVD) and sputtering. In other words, PECVD oxides or nitrides may include more pores or pinholes 20 in dielectric layer 18 . The density of pores or pinholes 20 in dielectric layer 18 may be greater than 10 6 pinholes/cm 2 and can be controlled by manipulating the deposition parameters of PECVD. For example, PECVD deposition parameters of low temperature in the range from 25° C. to 250° C., low power density in the range from 1 mW/cm 2 to 100 mW/cm 2 , and low pressure in the range from 10 mtorr. to 1000 mtorr. leads to the deposition of porous or low quality oxides/nitrides which include a high density of pores or pinholes 20 . The other methods mentioned above can also be used as long as the density of pinholes can be greater than 10 6 pinholes/cm 2 .
[0012] FIG. 2 is a cross-section view of structure 10 ′ which is formed by chemically etching structure 10 . Structure 10 with porous oxides/nitrides as dielectric layer 18 as shown in FIG. 1 may be dipped into an alkaline solution such as KOH, tetra methyl ammonium hydroxide (TMAH) or NH 3 OH for a time in the range from 10 sec to 20 min to anisotropically etch surface 15 of layer 14 which may be originally smooth. The temperature of the anisotropic etching process, which includes the temperature of the etching solution, may be in the range from 23° C. for a slow etch rate to an aqueous alkaline solution boiling temperature of about 100° C. for a fast etch rate. The etching time of the anisotropic etching should be less than the time required for growing inverted pyramid patterns that impinge or overlap an adjacent inverted pyramid on the surface.
[0013] The etching solution passes or penetrates through pores or pinholes 20 in layer 18 , widens up original pinholes 20 shown as 20 ′ in FIG. 2 , and reaches surface 15 of layer 14 to anisotropically etch Si or Si containing surface 15 of layer 14 to form inverted pyramid patterns having a depth in the range from 100 nm to 10 μm and a width in the range from 200 nm to 20 μm. Therefore, increasing the density of pores or pinholes 20 in layer 18 in the range from 10 6 /cm 2 to 10 8 /cm 2 achieves a higher density of inverted pyramids in the same range from 10 6 inverted pyramids/cm 2 to 10 8 inverted pyramids/cm 2 since surface 15 ′ of layer 14 ′ is exposed to the etching solution through pores or pinholes 20 ′ in dielectric layer 18 ′ forming inverted pyramids. Dielectric layer 18 may have a thickness in the range from 10 nm to 100 nm. The thickness of dielectric layer 18 such as an oxide must be thick enough in the range from 10 nm to 100 nm so as not to be removed during the anisotropic etching process, and yet not too thick in the range from 100 nm to 1 μm prohibit the etching solution from penetrating through pinholes 20 in dielectric layer 18 . After finishing anisotropic etching of Si surface 15 ′ comprised of inverted pyramid patterns, Si surface 15 ′ of layer 14 ′ is ready to serve as a textured surface for solar cell applications.
[0014] It should be noted that pinholes 20 in dielectric layer 18 are not necessarily physical openings in dielectric layer 18 at the time dielectric layer 18 is deposited. For example, some or all of pinholes 20 may comprise pinhole-sized regions in dielectric layer 18 that are less resistant than the rest of the dielectric layer to the anisotropic etch used to etch layer 14 , with the result that some or all of physical openings 20 ′ would be formed at early stages of the anisotropic etch, rather than being present originally.
[0015] FIG. 3 is a cross-section view of structure 10 ″ after removing porous oxide and/or nitride layer 18 ′ shown in FIG. 2 . Layer 18 ′ can be removed by etching with hydrofluoric acid followed by rinsing Si or Si containing surface 15 ′ with deionized (DI) water to provide a clean textured Si or Si containing surface 15 ′ comprised of inverted pyramid patterns.
[0016] While there has been described and illustrated a method for forming a textured Si surface comprised of inverted pyramid patterns via anisotropic etching through a porous dielectric layer containing pores or pinholes, it will be apparent to those skilled in the art that modifications and variations are possible without deviating from the broad scope of the invention which shall be limited solely by the scope of the claims appended hereto. | A low cost method is described for forming a textured Si surface such as for a solar cell which includes forming a dielectric layer containing pinholes, anisotropically etching through the pinholes to form inverted pyramids in the Si surface and removing the dielectric layer thereby producing a high light trapping efficiency for incident radiation. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to compounds of cyclic lipopeptide antibiotic locillomycin (Locillomycin-A, Locillomycin-B, Locillomycin-C) and methods for making and using to the treatment of infections to fungi, bacteria and virus.
BACKGROUND OF THE INVENTION
[0002] The discovery and application of a cyclic lipopeptide antibiotic started in the 40s of the 20 th century, followed by a wide spread of research and application in the areas of medicine, agriculture and animal husbandry and industry due to their very effectiveness to treat infections of fungi, bacteria and virus, and good hemolytic performance. Some of them are of even active anticancer agents. The cyclic lipopeptide antibiotics are mainly derived from microorganisms, especially from Bacillus , and since then, more than 20 different types of them being discovered and used worldwide. These antibiotics have a common structure comprised by a core cyclic peptide with 7 to 10 amino acids and an exocyclic acyl group of hydrophobic fatty acid moiety. According to the chemical structure, they are grouped into 1) Surfacin, which is illustrated as follows:
[0003] Surfactin Family
[0000]
[0000] Variants Length and branching of the acyl chain Esperin** L-Glu-L-Leu-D-Leu-L-Val-L-Asp-D-Leu-L-Leu-COOH Lichenysin*** L-XL -L-XL -D-Leu-L-XL -L-Asp-D-Leu-L-XL i-C -ai-C n-C i-C ai-C Pumilacidin L-Glu-L-Leu-D-Leu-L-Leu-L-Asp-D-Leu-L-XP Surfactin L-Glu-L-XS -D-Leu-L-XS -L-Asp-D-Leu-L-XS i-C n-C i-C ai-C ** the β-carboxyl of Asp5 is engaged in the lactone *** or halobacillin XL = Gln or Glu; XL = Leu or Ile; XL and XL = Val or Ile; XP = Val or Ile; XS = Val, Leu or Ile; XS = Ala, Val, Leu or Ile; XS = Val, Leu or Ile n, liner indicates data missing or illegible when filed
2) Iturin, which is illustrated as follows:
[0004] Iturin Family
[0000]
[0000] Bacillomycin D L-Asn-D-Tyr-D-Asn-L-Pro-L-Glu-D-Ser-L-Thr n-C ,i-C ,ai-C Bacillomycin F L-Asn-D-Tyr-D-Asn-L-Glu-L-Pro-D-Asn-L-Thr i-C ,i-C ,ai-C Bacillomycin L L-Asp-D-Tyr-D-Asn-L-Ser-L-Gln-D-Ser-L-Thr n-C ,i-C ,ai-C Bacillomycin LC* L-Asn-D-Tyr-D-Asn-L-Ser-L-Gln-D-Ser-L-Thr n-C ,i-C ,ai-C ,i-C Iturin A L-Asn-D-Tyr-D-Asn-L-Gln-L-Pro-D-Asn-L-Ser n-C ,i-C ,ai-C Iturin A L-Asn-D-Tyr-D-Asn-L-Gln-L-Pro-D-Asn-L-Ser n-C ,i-C Iturin C L-Asp-D-Tyr-D-Asn-L-Gln-L-Glu-D-Asn-L-Ser n-C ,i-C ,ai-C Mycosubtilin L-Asn-D-Tyr-D-Asn-L-Gln-L-Pro-D-Ser-L-Asn n-C ,i-C ,ai-C *or bacillopeptin indicates data missing or illegible when filed
3) Fengycin, which is illustrated as follows:
[0005] Fengycin Family
[0000]
[0000]
Fengycin A**
L-Glu-D-Orn-D-Tyr-D-
ai-C 15 , i-C 16 ,
αThr-L-Glu-D-Ala-L-
n-C 16
Pro-L-Gln-L-Tyr-L-Ile
Fengycin B**
L-Glu-D-Orn-D-Tyr-D-
ai-C 15 , i-C 16 ,
αThr-L-Glu-D-Val-L-
n-C 16 ,C 17
Pro-L-Gln-L-Tyr-L-Ile
Plipastatin A
L-Glu-D-Orn-L-Tyr-D-
n-C 16 , ai-C 17
αThr-L-Glu-D-Ala-L-
Pro-L-Gln-D-Tyr-L-Ile
Plipastatin B
L-Glu-D-Orn-L-Tyr-D-
n-C 16 , ai-C 17
αThr-L-Glu-D-Val-L-
Pro-L-Gln-D-Tyr-L-Ile
**double bond between carbons 2-3, 3-4, or 13-14 were reported for some acyl chains
[0006] The Surfacin family has a polar molecule structure, which is characterized by a core cyclic peptide with 7 amino acid residues and an exocyclic acyl group of β-hydroxyl fatty acid moiety with 13 to 15 carbon atoms. It demonstrates a strong performance of hemolysis and inhibitions of bacterium, virus and cancer cell activities by acting on the phospholipid bilayer of cell membrane. Due to the variability of 7 amino acid residues in the core cyclic peptide, this family provides varieties of antibiotics including Surfacin from Bacillus subtilis, Pumilacidin from Bacillus pumilus and lichenysin from Bacillus licheniformis.
[0007] The Iturin family is characterized by a chemical structure comprising of a core cyclic peptide with 7 amino acid residues and an exocyclic acyl group of β-Amino fatty acid moiety with 14 to 17 carbon atoms. It manifests a strong performance of hemolysis and inhibitions of fungus activity by affecting on the surface tension of the cell membrane to form micro pores which cause the leakage of electrolyte and other important ions. However, it shows weak effects on virus and bacteria. This family of antibiotics, including 9 isomers of Iturin-A, Iturin-C, Iturin-D, Iturin-E, Bacillomycin-D, Bacillomycin-F, Bacillomycin-L, Bacillomycin-Lc and Mycosubtilin, is mainly derived from Bacillus subtilis strains and their neighbor species.
[0008] The Fengycin family is characterized by a chemical structure comprising of a core cyclic peptide with 10 amino acid residues and an exocyclic acyl group of either saturated or unsaturated β-hydroxyl fatty acid moiety with 14 to 18 carbon atoms. It manifests less effective on the performance of hemolysis than Surfacin family and Iturin family, but more effective on the inhibitions of fungus activity and weaker on the inhibitions of bacteria and virus. This family of antibiotics, including 4 isomers of Fengycin-A, Fengycin-B, Plipastatin-A, Plipastatin-B, is mainly derived from Bacillus subtilis strains and their neighbor species.
[0009] This invent provides newly discovered cyclic lipopeptide antibiotic derivatives from the fermentation of Bacillus subtilis Bs916 (CGMCC No. 0808: Classification number in China General Microbiological Culture Collection Center). These derivatives have new structures, which are totally different from known cyclic lipopeptide antibiotics of Surfacin, Iturin and Fengycin, or the report of known antibiotics, and demonstrate strong antibiotic activities against fungi, bacteria and virus. Experiments revealed that the new derivatives had very effectiveness on the inhibition of fungi, bacteria and virus activities, and low side effect, good bioavailability and preparation adaptability, which are all desired characteristics for the potential application.
[0010] By the intensive research over the long history since the first discovery of antibiotics, there are tens of thousands of antibiotics in application worldwide. However, pathogens having antibiotic resistance for controlling previously treatable infectious become increasingly common Obviously, there is an urgent need for new antibiotics with novel mechanism of action. The present invention provides all related advantages for such antibiotics.
DETAILED DESCRIPTION OF THE INVENTION
[0000]
1. The present invention provides three compounds of cyclic lipopeptide antibiotic locillomycin, defined as Locillomycin-A, Locillomycin-B and Locillomycin-C thereof, according to structural formulae (II):
[0000]
[0012] The definitions are determined according to their chemical structures acquired from the analysis of biochemistry, chromatogram, spectrum and mass spectrum.
[0013] The present invent defined the derivatives are in the physical form of a white powder, and in the chemical form of a core cyclic peptide with an attachment of a fatty acid herein, the general chemical composition, after reaction, is C n H m NO, wherein the combinations of n and m can be and only be one of the three: n=13 and m=25, or n=14 and m=27, or n=15 and m=29. The “core cyclic peptide” is referred to a chemical structure comprising nine amino acid residues with at least one exocyclic amino acid terminal providing a point of attachment to the straight carbon chain defined above. The nine amino acid residues are connected with a sequence of 1 Thr, 2 D-Gln, 3 L-Asp, 4 L-Gly, 5 L-Asn, 6 L-Asp, 7 L-Gly, 8 L-Tyr, 9 L-Val herein, the β-hydroxy- of the 1 Thr reacted with the carboxyl of the 9 L-Val to form the core cyclic peptide structure via an ester bond. The carboxyl of the fatty acid reacted to the exocyclic amino acid emanating from the 1 Thr to form an amide bond. The derivatives can easily dissolve in methanol and dimethyl sulfoxide, but weakly dissolve in water and ethanol. The differences of the chemical structure among the Locillomycin-A (13 carbon atoms), Locillomycin-B (14 carbon atoms) and Locillomycin-C (15 carbon atoms) only come from the different length of the long-chain acyl group, specifically a methylene (—CH 2 ) varietion in the side chain of the fatty acid so that Locillomycin-A (C 52 H 79 N 11 O 18 ), Locillomycin-B (C 53 H 81 N 11 O 18 ) and Locillomycin-C(C 54 H 83 N 11 O 18 ).
[0014] The present invent provides newly discovered cyclic lipopeptide antibiotic derivatives from the fermentation of Bacillus subtilis Bs916 (CGMCC No. 0808: Classification number in China General Microbiological Culture Collection Center, registered on 30 Sep. 2002).
[0015] The present invent follows a route steps below to make and use the compounds thereof,
1, A method for producing Locillomycin-A, Locillomycin-B and Locillomycin-C by fermentation: the fermentation is characterized by culturing Bacillus subtilis Bs916 (CGMCC No. 0808: Classification number in China General Microbiological Culture Collection Center, registered on 30 Sep. 2002) in two stages: firstly, culturing Bs916 in tubes containing LB liquid medium at 37° C. and shaking at 200 r/m on a shaker for 24 hours; secondly, transferring the medium from the first stage into bottles containing LB liquid medium at 28° C. and shaking at 180 r/m on a shaker for 72 hours, then collecting all media to supply to the next route for processing. 2, The separation and purification of the compounds of Locillomycin-A, Locillomycin-B and Locillomycin-C: The processes of separation and purification are characterized by collecting all the fermentation media according to the first step into centrifuge tubes and centrifuging at 5000 r/m for 30 minutes, prior to transferring supernatant into new tubes and adjusting pH to 2.8 and staying at room temperature over night. The supernatant then is centrifuged at room temperature and 8000 r/m for 25 minutes to precipitate, which is followed by two extractions over 48 hours with pure methanol and filtered through a 0.22 μm membrane filter. The filtrate is diluted with deionized water to methanol concentration (v:v) of 30%, and adjusted pH to 7.0, and gravitationally passed through an Amino (NH 2 ) solid phase extraction (Agilent Technologies, Amino (NH 2 )-Box, 6 ml tubes, 500 mg) at room temperature. The subsequent stationary phase is rinsed at room temperature by 10 ml of gradient eluent of a mixture, which is prepared first with deionized water in pure methanol (v/v=50/50), followed by pure methanol, and third by formic acid/methanol v/v=0.5/99.5, then by formic acid/methanol v/v=1/99, and finally by formic acid/methanol v/v=2/98. The eluent of the final rinse with formic acid/methanol v/v=2/98 is collected, and prior to gravitationally passing through a LC-18 solid phase extraction (Agilent Technologies, Supelclean LC-18, 3 ml tubes, 500 mg) at room temperature and adjusting pH to 7.0, drying with pure nitrogen blow, and diluting with deionized water to methanol concentration (v:v) of 30%. The subsequent stationary phase is rinsed at room temperature with 9 ml of gradient eluent of methanol-water solution, which is prepared first with deionized water in pure methanol (v/v=70/30), followed by deionized water/pure methanol (v/v=60/40), third with deionized water/pure methanol v/v=50/50), forth with deionized water/pure methanol v/v=40/60), fifth with deionized water/pure methanol v/v=30/70), finally with deionized water/pure methanol v/v=20/80). The eluents from solutions of deionized water/pure methanol v/v=50/50 and v/v=40/60 are collected, and prior to gravitationally passing through a LC-18 solid phase extraction (Agilent Technologies, Supelclean LC-18, 3 ml tubes, 500 mg) again at room temperature and drying with pure nitrogen blow, and diluting with deionized water to methanol concentration (v:v) of 30%. The subsequent stationary phase is rinsed at room temperature with 30 ml of gradient eluent of methanol-water solution, which is prepared first with deionized water in pure methanol (v/v=64/36), followed by deionized water/pure methanol (v/v=62/38), third with deionized water/pure methanol v/v=60/40), forth with deionized water/pure methanol v/v=58/42), fifth with deionized water/pure methanol v/v=56/44), fifth with deionized water/pure methanol v/v=54/46), fifth with deionized water/pure methanol v/v=52/48), fifth with deionized water/pure methanol v/v=50/50), finally with deionized water/pure methanol v/v=48/52). The eluent from deionized water/pure methanol v/v=60/40 contains compound Locillomycin-A. The eluent from deionized water/pure methanol v/v=56/44 contains compound Locillomycin-B. The eluent from deionized water/pure methanol v/v=52/48 contains compound Locillomycin-C. The eluents are separately dried by pure nitrogen blow and further vacuum dried to obtain final white powder-type compounds. 3, A method for analyzing the compounds of Locillomycin-A, Locillomycin-B and Locillomycin-C: In this step, the process is characterized by using HPLC on a C-18 column (5 μm; 250 by 4.6 mm; VYDAC 218 TP; VYDAC, Hesperia, Calif.) with the acetonitrile-water-trifluoroacetic acid solvent system (50:50:0.5 [vol/vol/vol]) at a flow rate of 0.5 ml min −1 . The retention times of 9.0 minutes, 13.0 minutes and 17.8 minutes and UV-visible spectrum at 230 nm are used to identify the Locillomycin-A, Locillomycin-B and Locillomycin-C respectively. 4, A method for appraising the structure of the compounds of Locillomycin-A, Locillomycin-B and Locillomycin-C: In this step, the process is characterized by the system analysis of data derived from UV spectra, amino acid identification, Edman degradation protein sequencing, 1 H-NMR, 13 C-NMR, 13 C-edited HSQC, HMBC, COSY, TOCSY, NOESY and/or ROESY. This process is detailed in the section of Example 5. 5, Determination of Antibiotic function for Locillomycin-A, Locillomycin-B and Locillomycin-C: In this step, the process is characterized by antimicrobial experiments, which are conducted by mixing Locillomycin-A, Locillomycin-B and Locillomycin-C separately into different plates containing LB medium and, then, inoculating pathogenic fungi, bacteria and virus into the plates, followed by incubation at 28° C. to check the effectiveness of antifungal ( rhizoctonia solani infectious), antibacterial (rice bacterial leaf spot pathogen infectious) functions. The experiments revealed that Locillomycin-A, Locillomycin-B and Locillomycin-C have strong antibiotic activities for inhibition of fungi and bacteria. 6, Test on compositions of acceptable carrier, excipient, diluent for treating infectious of a fungus, or a bacterium, or a virus, or combinations of fungi, bacteria and virus using Locillomycin-A, Locillomycin-B and Locillomycin-C: The acceptable carrier, excipient, diluent refer to as inertia materials to compose either solid, or semi solid, or liquid which can make into powders, tablets, dispersible powders, capsules, suppositories, cream and gel forms in pharmaceutical application. For solid forms, the acceptable carrier, excipient, diluent can be one of, or combinations of, diluent, flavoring agent, solubilizer, lubricant, suspending agent, binder, bulking agent and/or encapsulating material, in certain embodiments of which, they can be one, or combinations of magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, yellow addicted gum, methyl cellulose, sodium carboxymethyl cellulose, low boiling wax and cocoa butter. For powder forms, the acceptable carrier, excipient, diluent can be mixed with 5%-70% (w/w) of bioactive antibiotics, which is micronized in physical size. The liquid forms of the acceptable carrier, excipient, diluent refer to solutions, suspensions and emulsions such as injectable preparations of water and propylene glycol solution for parenteral administration, of which, pH and isotonic property can be adjusted easily. The liquid remedy can also be in the form of polyethylene glycol solution for oral medication after adjusted with coloring agent, flavoring agent, stabilizer and thickener. Other forms of preparation including dispersing bioactive Locillomycin-A, Locillomycin-B and Locillomycin-C in a viscous material such as natural or synthetic gums, or methyl cellulose, or methyl cellulose sodium acid are also acceptable. The doses are normally in the a range of 1 to 1000 mg active antibiotics per unit of delivery carrier, although the forms and compositions can vary. 7, Using Locillomycin-A, Locillomycin-B and Locillomycin-C in the compositions to treat infectious of fungi, bacteria and virus: In the embodiments of present invention, including treatments to the infectious of fungi, bacteria and virus, the results demonstrated a strong effectiveness of antibiotics and wide application possibilities.
BRIEF DESCRIPTION OF THE DRAWING
[0023] FIG. 1 . HPLC (High Performance Liquid Chromatographic) peak patterns of Locillomycin-A, Locillomycin-B, Locillomycin-C homologues
[0024] FIG. 2 . HPLC peak patterns of Locillomycin-A
[0025] FIG. 3 . HPLC peak patterns of Locillomycin-B
[0026] FIG. 4 . HPLC peak patterns of Locillomycin-C
[0027] FIG. 5 . UV spectrum of Locillomycin-A
[0028] FIG. 6 . UV spectrum of Locillomycin-B
[0029] FIG. 7 . UV spectrum of Locillomycin-C
[0030] FIG. 8 Amino acid analysis of Locillomycin-A, Locillomycin-B, Locillomycin-C by gas chromatography
[0031] FIG. 9 . DL-amino acid analysis of Locillomycin-A, Locillomycin-B, Locillomycin-C by HPLC
[0032] FIG. 10 . Edman degradation sequencing Locillomycin-A, Locillomycin-B, Locillomycin-C
[0033] FIG. 11 . Mass spectrum of Locillomycin-A
[0034] FIG. 12 . Mass spectrum of Locillomycin-B
[0035] FIG. 13 . Mass spectrum of Locillomycin-C
[0036] FIG. 14 . Tandem mass spectrum of Locillomycin-A
[0037] FIG. 15 . Tandem mass spectrum of Locillomycin-B
[0038] FIG. 16 . Tandem mass spectrum of Locillomycin-C
[0039] FIG. 17 . 1 H-NMR spectrum of Locillomycin-A in 90% H 2 O/10% D 2 O
[0040] FIG. 18 . TOCSY spectrum of Locillomycin-A in 90% H 2 O/10% D 2 O
[0041] FIG. 19 . ROESY spectrum of Locillomycin-A in 90% H 2 O/10% D 2 O
[0042] FIG. 20 . 13 C-edited HSQC spectrum of Locillomycin-A in 90% H 2 O/10% D 2 O
[0043] FIG. 21 . 1 H-NMR spectrum of Locillomycin-B in CD 3 OH
[0044] FIG. 22 . 13 C-NMR spectrum of Locillomycin-B in CD 3 OH
[0045] FIG. 23 . 13 C-DEPT spectrum of Locillomycin-B in CD 3 OH
[0046] FIG. 24 . 1 H- 1 H COSY spectrum of Locillomycin-B in CD 3 OH
[0047] FIG. 25 . TOCSY spectrum of Locillomycin-B in CD 3 OH
[0048] FIG. 26 . ROESY spectrum of Locillomycin-B in CD 3 OH
[0049] FIG. 27 . 13 C-edited HSQC spectrum of Locillomycin-B in CD 3 OH
[0050] FIG. 28 . HMBC spectrum of Locillomycin-B in CD 3 OH
[0051] FIG. 29 . 1 H-NMR spectrum of Locillomycin-C in CD 3 OH
[0052] FIG. 30 . 13 C-NMR spectrum of Locillomycin-C in CD 3 OH
[0053] FIG. 31 . 1 H- 1 H COSY spectrum of Locillomycin-C in CD 3 OH
[0054] FIG. 32 . TOCSY spectrum of Locillomycin-C in CD 3 OH
[0055] FIG. 33 . ROESY spectrum of Locillomycin-C in CD 3 OH
[0056] FIG. 34 . 13 C-edited HSQC spectrum of Locillomycin-C in CD 3 OH
[0057] FIG. 35 . HMBC spectrum of Locillomycin-C in CD 3 OH
[0058] FIG. 36 . Sequential assignment and spin system identification of the cyclic peptide
[0059] FIG. 37 Important NOE and HMBC signals for the determination of site of the long chain acyl group
[0060] FIG. 38 . The antifungal activities of Locillomycin-A against Fusarium oxysporum
[0061] FIG. 39 . The inhibition activities of Locillomycin-A, Locillomycin-B, Locillomycin-C against Porcine epidemic diarrhea virus (PEDV)
METHODS OF MAKING AND USING THE SAME
[0062] The following embodiments provide demonstrations of, but not the limitations of, the present invention:
Example 1
The fermentation of Bacillus subtilis Bs916
[0063] All together, 80 liters of medium were collected by culturing Bacillus subtilis Bs916 in tubes containing LB liquid medium (10 g tryptone, 5 g yeast extraction, 5 g NaCl per Liter Liquid) at 37° C. and shaking at 200 r/m on a shaker for 24 hours; followed by transferring the medium into bottles each containing 5 ml of the LB liquid medium at 28° C. and shaking at 180 r/m on a shaker for 72 hours.
Example 2
Removal of Impurities from the Culturing Medium to Acquire Semi-Purified Antibiotic Mixture
[0064] Impurities are removed by centrifuging the collected medium at 5000 r/m for 30 minutes, prior to transferring supernatant into new tubes and adjusting pH to 2.8 and staying at room temperature over night. The supernatant then is centrifuged at room temperature and 8000 r/m for 25 minutes to precipitate, which is followed by two extractions over 48 hours with pure methanol and filtered through a 0.22 μm membrane filter to acquire 200 ml of semi-purified antibiotic mixture.
Example 3
Separation of Locillomycin-A, Locillomycin-B, Locillomycin-C from Semi-Purified Antibiotic Mixture
[0065] The antibiotic mixture is diluted with deionized water to methanol (v:v) concentration of 30%, and adjusted pH to 7.0, and gravitationally passed through an Amino (NH 2 ) solid phase extraction (Agilent Technologies, Amino (NH 2 )-Box, 6 ml tubes, 500 mg) at room temperature. The subsequent stationary phase is rinsed at room temperature by 10 ml of gradient eluent of a mixture, which is prepared first with deionized water in pure methanol (v/v=50/50), followed by pure methanol, and third by formic acid/methanol v/v=0.5/99.5, then by formic acid/methanol v/v=1/99, and finally by formic acid/methanol v/v=2/98. The eluent of the final rinse with formic acid/methanol v/v=2/98 is collected, and prior to gravitationally passing through a LC-18 solid phase extraction (Agilent Technologies, Supelclean LC-18, 3 ml tubes, 500 mg) at room temperature and adjusting pH to 7.0, drying with pure nitrogen blow, and diluting with deionized water to methanol (v:v) concentration of 30%. The subsequent stationary phase is rinsed at room temperature with 9 ml of gradient eluent of methanol-water solution, which is prepared first with deionized water in pure methanol (v/v=70/30), followed by deionized water/pure methanol (v/v=60/40), third with deionized water/pure methanol v/v=50/50), forth with deionized water/pure methanol v/v=40/60), fifth with deionized water/pure methanol v/v=30/70), finally with deionized water/pure methanol v/v=20/80). The eluents from solutions of deionized water/pure methanol v/v=50/50 and v/v=40/60 are collected, which contained Locillomycin-A, Locillomycin-B and Locillomycin-C mixture about 80 ml at purity of 94.4%.
[0066] The collected mixture was diluting with deionized water to methanol (v:v) concentration of 30%, then dried with pure nitrogen blow followed by to gravitationally pass through a LC-18 solid phase extraction (Agilent Technologies, Supelclean LC-18, 3 ml tubes, 500 mg) again at room temperature. The subsequent stationary phase is rinsed at room temperature with 30 ml of gradient eluent of methanol-water solution, which is prepared first with deionized water in pure methanol (v/v=64/36), followed by deionized water/pure methanol (v/v=62/38), third with deionized water/pure methanol v/v=60/40), forth with deionized water/pure methanol v/v=58/42), fifth with deionized water/pure methanol v/v=56/44), fifth with deionized water/pure methanol v/v=54/46), fifth with deionized water/pure methanol v/v=52/48), fifth with deionized water/pure methanol v/v=50/50), finally with deionized water/pure methanol v/v=48/52). The eluent from deionized water/pure methanol v/v=60/40 contains compound Locillomycin-A about 12 mg at purity of 95.7%. The eluent from deionized water/pure methanol v/v=56/44 contains compound Locillomycin-B about 10 mg at purity of 97.8%. The eluent from deionized water/pure methanol v/v=52/48 contains compound Locillomycin-C about 14 mg at purity of 98.8%. The eluents are separately dried by pure nitrogen blow and further vacuum dried to obtain final white powder-type compounds.
Example 4
Analyze the Compounds Using HPLC
[0067] The final white powder-type compounds were analyzed using HPLC on a C-18 column (5 μm; 250 by 4.6 mm; VYDAC 218 TP; VYDAC, Hesperia, Calif.) with the acetonitrile-water-trifluoroacetic acid solvent system (50:50:0.5 [vol/vol/vol]) at a flow rate of 0.5 ml min −1 . The retention times of 9.0 minutes, 13.0 minutes and 17.8 minutes and UV-visible spectrum at 230 nm were used to identify the Locillomycin-A, Locillomycin-B and Locillomycin-C respectively.
Example 5
Appraise the Chemical Structures of the Compounds
[0068] The final white powder-type compounds were appraised by system analysis with data acquired from UV spectra, amino acid identification, Edman degradation protein sequencing, 1 H-NMR, 13 C-NMR, 13 C-edited HSQC, HMBC, COSY, TOCSY, NOESY and/or ROESY. The main physical and chemical properties of Locillomycin-A, Locillomycin-B and Locillomycin-C are listed in Table 1.
[0000]
TABLE 1
Main physical and chemical properties of Locillomycin-A, Locillomycin-B and
Locillomycin-C
Locillomycin-A
Locillomycin-B
Locillomycin-C
Color and Shape
White Powder
White Powder
White Powder
Molecule Formula and
C 52 H 80 N 11 O 18
C 53 H 82 N 11 O 18
C 54 H 84 N 11 O 18
Molecule Weight
MW = 1145.6
MW = 1159.6
MW = 1173.6
UVλmax nm
230, 280
230, 280
230, 280
Retention Time (HPLC)
9.0 min
13.0 min
17.8 min
Solubility
Methanol, Dimethyl
Methanol, Dimethyl
Methanol, Dimethyl
Sulfoxide, Water
Sulfoxide, Water
Sulfoxide, Water
ESI-MS
1146.6 [M + H]
1160.6 [M + H]
1174.6 [M + H]
[0069] Characterization of all derivatives of Locillomycin (Locillomycin-A, Locillomycin-B, Locillomycin-C) was demonstrated by the signal assigning process and determining the molecular structure of the Locillomycin-C as an example. The assigning process started from connecting the fingerprint area of the ROESY spectrum of Locillomycin-C(H α : 3.6-4.9 ppm, H N : 7.4-8.8 ppm) as shown in the left panel of FIG. 36 . Then the TOCSY spectrum was used to identify the different spin systems of the amino acid residues (shown in the right panel of FIG. 36 ). By using these two spectra, we concluded that there were nine residues in the compound of the Locillomycin-C, which are consistent to the sequencing result of the same derivative. These amino acid residues are connected with a sequence of Thr1-Gln2-Asp3-Gly4-Asn5-Asp6-Gly7-Tyr8-Val9. The characteristic cross peaks of the side chain amide to 3 protons in the ROESY spectrum were used to differentiate the Asn to Asp residues. Several Thr1 to Val9 interactions observed in the ROESY spectrum (solid-line arrows in FIG. 37 ) show that these two residues are close in space, indicating a cyclic structure connected end-to-end. From the large peaks around 1.2-1.4 ppm in the 1 H spectrum, we conclude that a long alkyl group is attached to the cyclic peptide structure.
[0070] By using a 13 C-edited (CH 2 negative, CH 3 , CH positive) HSQC spectrum, protonated carbons were assigned after the assignment of most of the protons. So far, all known pieces of the compound contributed to 13 carbonyl signals while we observed 14 carbonyl signals in the 13 C spectrum. This indicated that there must be a carbonyl group in the long alkyl chain of this compound. The analysis of the HMBC spectrum resolved that this carbonyl signal was 177.27 ppm. The HMBC spectrum also had a cross peak between this carbonyl carbon and amide proton of the Thr1 (dotted-line arrow in FIG. 37 ). When cross peak of beta protons of Thr1 (5.48 ppm) to carbonyl group of Val9 (171.32 ppm) was observed in the HMBC, there was no cross peak observed from amide proton of Thr1 to carbonyl of Val9 ( FIG. 37 ). What was more, beta proton of Thr1 also showed interactions to alpha and beta protons of Val9 in the ROESY spectrum ( FIG. 36 ). From the above information, we could be able to figure out the attached site of the alkyl chain together with the carbonyl group (actually a long chain acyl group) and the pattern of the end-to-end connection of Thr1 to Val9 ( FIG. 36 ). From the chemical shift information provided by the 1 H and 13 C spectra and connectivities provided by the ROESY, TOCSY and HMBC spectra, we could predict the structure of the long chain acyl group as shown in FIG. 36 . We concluded the number of CH 2 groups by comparing our resolved structure pieces of the compound and its molecular weight from the Mass Spectrum and confirmed this number by the integration of the 1 H spectrum of the multi-CH 2 area. No branching was identified from NMR or MS. Thus, the molecular structure of the Locillomycin-C was identified by a complex analysis of its biochemical, chromatographical and different types of spectral data.
[0071] As noted above, the present invention provides cyclic lipopeptide antibiotic derivatives thereof, and uses thereof. The cyclic lipopeptide antibiotic derivatives of the present invention have a “core cyclic peptide” including at least one exocyclic amino acid indicated by a dashed line, which is illustrated as follows:
[0000]
[0072] In the above core cyclic peptide moiety, the dashed line emanating from the exocyclic amino acid indicates the point of attachment of a straight carbon chain herein, the general chemical composition is C n H m NO, wherein the combinations of n and m can be and only be one of the three: n=13 and m=25, or n=14 and m=27, or n=15 and m=29. The cyclic lipopeptide antibiotic derivatives of the present invention thus are defined as locillomycin lipopeptide antibiotics, and according to their carbon chain properties, further as Locillomycin-A (C 13 H 25 NO), Locillomycin-B (C 14 H 27 NO) and Locillomycin-C(C 15 H 29 NO). In this embodiment, the compounds of locillomycin lipopeptide antibiotic are derived from fermentation of Bacillus subtilis Bs916 (CGMCC No. 0808: Classification number in China General Microbiological Culture Collection Center), and followed by a process of purification.
[0073] As used herein, “locillomycin lipopeptide antibiotic” refers to an antibiotic comprising a cyclic peptide core that includes an exocyclic amino acid having a side chain with a primary fatty acid moiety.
[0074] As for Locillomycin-A and Locillomycin-B, analysis of NMR and MS spectra showed that they have an identical core cyclic peptide as to the Locillomycin-C (see the attached FIGS. 1 , 2 , 3 , 5 , 6 , 8 , 9 , 11 , 12 , 14 , 15 , and 17 to 28 ), except for a different molecular weight by 14 Dalton between each of the derivatives [Locillomycin-A (C 13 H 25 NO)<Locillomycin-B (C 14 H 27 NO)<Locillomycin-C(C 15 H 29 NO)], which comes from the different length of the long-chain acyl group. And their determination process will not be detailed here in this invention.
[0000] The NMR data of Locillomycin-A in H 2 O/D 2 O (90%/10%) is shown in Table 2.
[0000] TABLE 2 NMR data of Locillomycin-A (in 90% H 2 O/10% D 2 O) C′ residue α (ppm) β (ppm) h N (ppm) others (ppm) (ppm) Cyclic peptide (Chemical shifts of protons with corresponding carbon chemical shifts in the parentheses) T1 N/A (N/A) 5.50 (74.34) 8.34 γ: 1.15 (18.78) N/A Q2 4.36 (55.73) 1.91, 2.05 (30.52) 8.03 γ: 2.25 (33.53); Cδ: — (N/A); N/A ε: 6.73, 7.50 D3 4.64 (N/A) 2.62, 2.69 (41.28) 8.62 Cγ: — (N/A) N/A G4 3.90, 3.95 (45.53) — 8.35 — N/A N5 4.54 (55.18) 2.79 (38.68) 8.63 Cγ: — (N/A); δ: 6.93, 7.68 N/A D6 4.64 (N/A) 2.60, 2.72 (40.73) 8.51 Cγ: — (N/A) N/A G7 3.90, 3.99 (45.06) — 7.89 — N/A Y8 4.52 (58.44) 2.93, 3.08 (39.00) 7.82 Cγ: — (N/A); δ: 7.11 (N/A); N/A ε: 6.79 (N/A); Cζ: — (N/A) V9 4.23 (61.46) 1.99 (33.07) 7.76 γ: 0.77 (20.22), 0.75 (20.71) N/A long-chain acyl group (Chemical shifts of protons with corresponding carbon chemical shifts in the parentheses, in ppm) 1′ — (N/A) 2′ 2.49 (38.37) 3′ 1.62 (28.16) 4′-11′ 0.98~1.20 (30.7-32.7) 12′ N/A (N/A) 13′ 0.77 (13.69) note: —: no such nucleus; N/A: assignment not available
The NMR data of Locillomycin-B in CD 3 OH is shown in Table 3 (the chemical shifts of CD 3 OH are taken as references, 1 H, 3.3 ppm, 13 C: 49 ppm),
[0000] TABLE 3 The NMR data of Locillomycin-B (in CD 3 OH) H N C′ α (ppm) β (ppm) (ppm) others (ppm) (ppm) Cyclic peptide (Chemical shifts of protons with corresponding carbon chemical shifts in the parentheses) T1 4.75 (57.63) 5.44 (71.93) 8.38 γ: 1.21 (16.73) 171.26 Q2 4.36 (54.06) 1.91, 2.06 (29.38) 8.06 γ: 2.23 (31.87); Cδ: — (177.69); 173.43 ε: 6.82, 5.54 D3 4.71 (52.00) 2.77, 2.86 (36.40) 8.70 Cγ: — (174.13) 173.97 G4 3.93, 3.83 (43.94) — 8.17 — 172.70 N5 4.55 (53.58) 2.74, 2.84 (36.95) 8.64 Cγ: — (174.29); δ: 6.99, 7.67 174.39 D6 4.67 (52.76) 2.89 (35.78) 8.49 Cγ: — (174.00) 173.52 G7 3.96 (43.61) — 8.13 — 172.22 Y8 4.47 (57.69) 2.94, 3.14 (37.29) 7.87 Cγ: — (129.49); δ: 7.16 (131.17); 174.08 ε: 6.70 (116.25); Cζ: — (157.25) V9 4.17 (60.41) 2.07 (30.87) 7.57 γ: 0.84 (19.18), 0.89 (18.71) 171.44 long-chain acyl group (Chemical shifts of protons with corresponding carbon chemical shifts in the parentheses, in ppm) 1′ — (177.48) 2′ 2.41 (36.81) 3′ 1.64 (27.14) 4′-12′ 1.23~1.35 (30.3-31.3) 13′ 1.30 (23.75) 14′ 0.89 (14.47) note: —: no such nucleus; N/A: assignment not available
The NMR data of Locillomycin-C in CD 3 OH is shown in Table 3 (the chemical shifts of CD 3 OH are taken as references, 1 H, 3.3 ppm, 13 C: 49 ppm),
[0000] TABLE 4 The NMR data of Locillomycin-C (in CD 3 OH) H N C′ α (ppm) β (ppm) (ppm) others (ppm) (ppm) Cyclic peptide (Chemical shifts of protons with corresponding carbon chemical shifts in the parentheses) T1 4.75 (57.43) 5.48 (72.14) 8.33 γ: 1.19 (16.79) 171.08 Q2 4.30 (54.68) 1.98, 2.04 (29.09) 8.01 γ: 2.25 (32.07); Cδ: — (177.74); 173.24 ε: 6.65, 7.64 D3 4.63 (53.04) 2.65, 2.69 (39.81) 8.56 Cγ: — (177.37) 174.97 G4 3.92, 3.80 (43.90) — 8.20 — 173.10 N5 4.51 (54.14) 2.76 (37.14) 8.74 Cγ: — (174.41); δ: 6.96, 7.83 174.36 D6 4.56 (53.53) 2.65, 2.76 (38.57) 8.47 Cγ: — (177.55) 174.51 G7 4.09, 3.93 (43.46) — 8.04 — 172.49 Y8 4.41 (58.05) 2.98, 3.12 (37.43) 7.92 Cγ: — (129.49); δ: 7.16 (131.23); 174.05 ε: 6.69 (116.35); Cζ: — (157.24) V9 4.22 (59.99) 2.07 (31.19) 7.53 γ: 0.84 (19.176), 0.88 (18.61) 171.32 long-chain acyl group (Chemical shifts of protons with corresponding carbon chemical shifts in the parentheses, in ppm) 1′ — (177.27) 2′ 2.41 (36.84) 3′ 1.63 (27.14) 4′-13′ 1.2~1.4 (30.3-31.0) 14′ 1.28 (23.69) 15′ 0.86 (11.71) note: —: no such nucleus; N/A: assignment not available
The 2 nd degree MS characteristics of molecule mass, relative abundance, molecule formula and speculated sequence of fragment of Locillomycin-A are summarized in Table 5.
[0000] TABLE 5 The 2 nd degree MS characteristics of the fragment of Locillomycin-A Molecule Relative Molecule Weight Abundance Formula Sequence 212.1 53 C 13 H 26 O 1 N 1 CH 3 (CH 2 ) 11 CONH 221.1 105 C 11 H 13 N 2 O 3 Gly-Tyr 244.1 74 C 9 H 14 N 3 O 5 Gln-Asp 280.3 268 C 14 H 22 N 3 O 3 Tyr-Val 297.1 51 C 17 H 33 N 2 O 2 Thr(Link) 301.3 50 C 11 H 17 N 4 O 6 Gln-Asp-Gly 336.3 60 C 15 H 18 N 3 O 6 Asp-Gly-Tyr 397.4 55 C 22 H 41 N 2 O 4 Val-Thr(Link) 398.2 63 C 21 H 40 N 3 O 4 Thr(Link)-Gln 402.1 54 C 14 H 20 N 5 O 9 Asp-Gly-Asn-Asp 415.4 81 C 15 H 23 N 6 O 8 Gln-Asp-Gly-Asn 459.2 47 C 16 H 23 N 6 O 10 Asp-Gly-Asn-Asp-Gly 507.1 72 C 21 H 27 N 6 O 9 Gly-Asn-Asp-Gly-Thr 530.2 277 C 19 H 28 N 7 O 11 Gln-Asp-Gly-Asn-Asp 587.1 106 C 21 H 31 N 8 O 12 Gln-Asp-Gly-Asn-Asp- Gly 622.2 97 C 25 H 32 N 7 O 12 Asp-Gly-Asn-Asp-Gly- Tyr 640.4 74 C 31 H 54 N 5 O 9 Val-Thr(Link)-Gln-Asp 688 69 C 36 H 58 N 5 O 8 Tyr-Val-Thr(Link)-Gln 721.2 83 C 30 H 41 N 8 O 13 Asp-Gly-Asn-Asp-Gly- Tyr-Val 732.1 49 C 37 H 58 N 5 O 10 Asp-Gly-Tyr-Val- Thr(Link) 750.3 51 C 30 H 40 N 9 O 14 Gln-Asp-Gly-Asn-Asp- Gly-Thr 849.4 193 C 35 H 49 N 10 O 15 Gln-Asp-Gly-Asn-Asp- Gly-Tyr-Val 860.5 52 C 42 H 66 N 7 O 12 Tyr-Val-Thr(Link)- Gln-Asp-Gly 884.4 50 C 38 H 62 N 9 O 15 Thr(Link)-Gln-Asp- Gly-Asn-Asp-G1y3 975.6 41 C 46 H 71 N 8 O 15 Asp-Gly-Tyr-Val-Thr (Link)-Gln-Asp 983.6 47 C 43 H 71 N 10 O 16 Val-Thr(Link)-Gln- Asp-Gly-Asn-Asp 1146.6 404 C 52 H 80 N 11 O 18 locillomycin A + H
Thr(link): represent the amino of a Thr reacted with the fatty acid (CH 3 (CH 2 ) 11 COOH) to form amide bond. The 2″ degree MS characteristics of molecule mass, relative abundance, molecule formula and speculated sequence of fragment of Locillomycin-B are summarized in Table 6.
[0000] TABLE 6 The 2 nd degree MS characteristics of the fragment of Locillomycin-B Molecule Relative Molecule Weight Abundance Formula Sequence 221 47 C 11 H 13 N 2 O 3 Gly-Tyr 244 87 C 9 H 14 N 3 O 5 Gln-Asp 287.1 48 C 10 H 15 N 4 O 6 Asn-Asp-Gly 336.1 81 C 15 H 18 N 3 O 6 Asp-Gly-Tyr 402.4 56 C 14 H 20 N 5 O 9 Asp-Gly-Tyr-Asp 415 54 C 15 H 23 N 6 O 8 Gln-Asp-Gly-Asn 507.3 61 C 21 H 27 N 6 O 9 Gly-Asn-Asp-Gly-Tyr 587.2 99 C 21 H 31 N 8 O 12 Gln-Asp-Gly-Asn-Asp-Gly 603.9 76 C 33 H 55 N 4 O 6 Gly-Tyr-Val-Thr(Link) 622 130 C 25 H 32 N 7 O 12 Asp-Gly-Asn-Asp-Gly-Tyr 721.2 94 C 30 H 41 N 8 O 13 Asp-Gly-Asn-Asp-Gly- Tyr-Val 750.1 45 C 30 H 40 N 9 O 14 Gln-Asp-Gly-Asn-Asp- Gly-Tyr 832.1 63 C 41 H 66 N 7 O 11 Asn-Asp-Gly-Tyr-Val- Thr(Link) 849.3 233 C 35 H 49 N 10 O 15 Gln-Asp-Gly-Asn-Asp- Gly-Tyr-Val 898.7 89 C 39 H 64 N 9 O 15 Thr(Link)-Gln-Asp-Gly- Asn-Asp-Gly 917.5 80 C 44 H 69 N 8 O 13 Gly-Asn-Asp-Gly-Tyr- Val-Thr(Link) 940.1 50 C 42 H 70 N 9 O 15 Val-Thr(Link)-Gln-Asp- Gly-Asn-Asp 1160.6 366 C 53 H 82 N 11 O 18 locillomycin B + H
Thr(link): represent the amino of a Thr reacted with the fatty acid (CH 3 (CH 2 ) 12 COOH) to form amide bond. The 2 nd degree MS characteristics of molecule mass, relative abundance, molecule formula and speculated sequence of fragment of Locillomycin-C are summarized in Table 7.
[0000] TABLE 7 The 2nd degree MS characteristics of the fragment of Locillomycin-C Molecule Relative Molecule Weight Abundance Formula Sequence 172.2 62 C 6 H 10 N 3 O 3 Gly-Asn 221 190 C 11 H 13 N 2 O 3 Gly-Tyr 230.1 49 C 8 H 12 N 3 O 5 Asn-Asp 244 303 C 9 H 14 N 3 O 5 Gln-Asp 287.1 181 C 10 H 15 N 4 O 6 Asn-Asp-Gly 301.2 106 C 11 H 17 N 4 O 6 Gln-Asp-Gly 326 87 C 19 H 36 N 1 O 3 Thr(Link) 336 94 C 15 H 18 N 3 O 6 Asp-Gly-Tyr 344.1 50 C 12 H 18 N 5 O 7 Gly-Asn-Asp-Gly 402.2 69 C 14 H 20 N 5 O 9 Asp-Gly-Asn-Asp 415.2 100 C 15 H 23 N 6 O 8 Gln-Asp-Gly-Asn 425.2 79 C 24 H 45 N 2 O 4 Val-Thr(Link) 450.1 65 C 19 H 24 N 5 O 8 Asn-Asp-Gly-Tyr 459.1 51 C 16 H 23 N 6 O 10 Asp-Gly-Asn-Asp 507.1 59 C 21 H 27 N 6 O 9 Gly-Asn-Asp-Gly-Tyr 530 124 C 19 H 28 N 7 O 11 Gln-Asp-Gly-Asn-Asp 553 192 C 29 H 53 N 4 O 6 Val-Thr(Link)-Gln 569.3 99 C 28 H 49 N 4 O 8 Thr(Link)-Gln-Asp 587 79 C 21 H 31 N 8 O 12 Gln-Asp-Gly-Asn-Asp-Gly 588.4 72 C 33 H 54 N 3 O 6 Tyr-Val-Thr(Link) 622.1 72 C 25 H 32 N 7 O 12 Asp-Gly-Asn-Asp-Gly 716.1 52 C 38 H 62 N 5 O 8 Tyr-Val-Thr(Link)-Gln 849.2 165 C 35 H 49 N 10 O 15 Gln-Asp-Gly-Asn-Asp-Gly-Tyr-Val 912.2 61 C 40 H 66 N 9 O 15 Thr(Link)-Gln-Asp-Gly-Asn-Asp-Gly 931.8 60 C 45 H 71 N 8 O 13 Gly-Asn-Asp-Gly-Tyr-Val-Thr(Link) 1174.6 69 C 54 H 84 N 11 O 18 LocillomycinC + H
Thr(link): represent the amino of a Thr reacted with the fatty acid (CH 3 (CH 2 ) 13 COOH) to form amide bond.
[0075] The HPLC analysis revealed the locillomycin derivatives have a core cyclic peptide with amino acid residues sequentially as L-Thr, D-Gln, L-Asp, L-Gly, L-Asn, L-Asp, L-Gly, L-Tyr and L-Val.
Example 6
Experiment on Anti-Fungus with Locillomycin-A, Locillomycin-B and Locillomycin-C
[0076] The anti-fungi experiment, with 6 treatments of different drug concentration and three replicates each treatment and sterile water as blank check, was conducted by mixing Locillomycin-A, Locillomycin-B and Locillomycin-C separately into different plates containing LB medium and, then, inoculating pathogenic fungi in the center of the plates, followed by incubation at 28° C. to check the effectiveness of antifungal function. The criteria of the effectiveness were defined as the size of orthogonal cross diameter of the pathogen growth. The experiments revealed that Locillomycin-A, Locillomycin-B and Locillomycin-C have strong antibiotic activities for inhibition of fungi (Table 8).
[0000]
TABLE 8
The effects of Locillomycin-A, Locillomycin-B and Locillomycin-C
on Pathogenic fungi
Locillomycin A
Locillomycin B
Locillomycin C
Pathogenic
IC 50
IC 90
IC 50
IC 90
IC 50
IC 90
Fungi
(μg/ml)
(μg/ml)
(μg/ml)
(μg/ml)
(μg/ml)
(μg/ml)
Rhizoctonia
15.5
45.9
13.8
40.6
12.4
38.6
solani
Fusarium
12.5
56.3
11.6
48.9
10.3
46.8
oxysporum
Fusarium
25.4
>100
22.6
>100
21.7
>100
graminearum
Example 7
Experiment on Anti-Bacterium with Locillomycin-A, Locillomycin-B and Locillomycin-C
[0077] The anti-bacterium experiment, with sterile water as blank check, was conducted by mixing different doses of Locillomycin-A, Locillomycin-B and Locillomycin-C separately into different plates containing LB medium and, then, evenly inoculating rice bacterial leaf spot pathogen onto the surface of the plates, followed by inverted incubation at 28° C. to check the effectiveness of antifungal function. The criteria of the effectiveness were defined as the minimum inhibition concentration (MIC) in the non-bacterium colony plate of the pathogen growth. The experiments revealed that the MIC of Locillomycin-A was 6.3 μg/ml; Locillomycin-B was 5.8 μg/ml; and Locillomycin-C was 5.4 μg/ml. The results demonstrated that Locillomycin-A, Locillomycin-B and Locillomycin-C have strong antibiotic activities for inhibition of bacterium growth.
Example 8
Experiment on Anti-Virus with Locillomycin-A, Locillomycin-B and Locillomycin-C
[0078] The anti-virus experiment was designed using Porcine Epidemic Diarrhea Virus (PEDV) as an indicator; conducted on a 24-well plate containing a single layer of Vero cell in each well, which was infected with PEDV at a multiplicity of infection (MOI), and incubated at 37° C. After one hour, different concentrations of mixtures of Locillomycin-A, Locillomycin-B and Locillomycin-C were introduced to treatments, and continuously incubated at 37° C. for 36 hours. At the end of the experiment, RNA of the virus was extracted from the wells, and quantified with fluorescent qPCR. The results revealed that the PEDV infection could be effectively inhibited by locillomycin mixture especially that of concentration at the 10 μg/ml, which reduced the virus copy by 300 times. | This invention provides new cyclic lipopeptide antibiotic Locillomycin (Locillomycin-A, Locillomycin-B, Locillomycin-C) that display very strong antifungal, antibacterial, antivirus activities in a variety of contexts in vitro; methods of making and using the compounds, wherein Locillomycin-A, Locillomycin-B and Locillomycin-C are derived and purified from the culture of Bacillus subtilis Bs916. | 0 |
BACKGROUND OF THE INVENTION
[0001] The present invention pertains to a means of synchronizing the rotary shear and cutoff at order change in the dry end conversion of a corrugated web. In particular, the invention relates to a method for achieving a continuous web order change with the associated order change waste minimized and cut and slit so as to reduce potential for jam-up as it exits the cutoff knife into a stacking system.
[0002] In a corrugator dry end, where a corrugated paperboard web is longitudinally scored and slit into multiple parallel output webs (or “outs”), the outs are directed through one or more downstream cutoff knives which cut the output webs into selected sheet lengths. When two cutoff knives are used, they are vertically separated and each is capable of cutting the full corrugator width web. A web selector positioned downstream of the slitter/scorer divides the outs into two groups, one of which is directed to the upper cutoff knife and the other to the lower cutoff knife. Order changes must be effected while the upstream corrugator wet end continues to produce and deliver the continuous web to the slitter/scorer. An order change will typically result in a change in widths of the output webs, requiring redirection of at least a central portion of the web from one knife level to the other and possibly changes in edge trim widths as well.
[0003] The prior art has developed a gapless or plunge-style order change for corrugated dry ends utilizing double level cutoff knives. In this system, there are two slitter/scorer stations immediately adjacent to one another in the direction of web movement and through both of which the web travels. At order change, one slitter/scorer, operating on the currently running order, will lift out of operative engagement with the web, and the other slitter/scorer, which is set to the new order alignment, plunges down into operative engagement with the web. The result is a small order change region of corrugated web with overlapping slits and scores.
[0004] To effectuate such a gapless order change, a means must be provided to accommodate redirection of the central portion of the web in the web selector device from one knife level to the other. In U.S. Pat. No. 5,496,431, a laterally adjustable cutting tool, positioned over the center of the web, makes a cut in the order change region connecting the inner-most slit in the currently running order to the inner-most slit in the new order to allow a repositioning of the web directing forks in the web selector device.
[0005] In one embodiment of the above identified patent, the inner-most slits on the old and new orders are connected by a running diagonal cut to provide smooth transition in the output webs directed to the upper and lower cutoff knives. With this concept, there is a requirement to have overlapping slits on the outer edges of the web to allow straight lateral cut across the slits for a trim width change. Internal slits can be offset in the order change region in the running web direction, or overlapped. If the slits are offset, then the width of the scrap piece emerging from the cutoff knife may be wider than the individual outs on one level of the knife, creating a problematic situation upon discharge of the stack form that level. If the slits are overlapped, then there is potential for creation of small pieces, some of which have diagonal cuts that may not fit nicely on top of the stack onto which the cut sheets are directed.
[0006] In another embodiment of the above identified patent, the innermost slits of the old and new orders are connected by a lateral cut that requires the overlap of the innermost slits. By overlapping all slits, it is possible that the scrap associated with the order change region will emerge from the cutoff knife slit to the width of the old order sheets and a length shorter than the old order sheets so that these sheets are simply discharged into the top of the last stack in the old order, where they can be removed by the operator. Unfortunately, it is equally likely that several small odd-sized pieces may be created that will not have a stack to land on and that create high probability of a stacker jam-up. By only overlapping the innermost slits to create an opportunity for redirection of the webs at the web selector table and by controlling the cutoff knife to stop cutting prior to the order change region in the old order and after the order change region has passed on the new order it is possible to avoid the creation of small odd-sized pieces. The scrap piece created with this technique is typically larger than the sheets cut on the expiring order. In this case, the order change region scrap will not fit onto the top of the stack unless the stacker backstop is backed away when the scrap piece enters the stacker. This is problematic in that moving the backstop away to accommodate the long scrap sheet can allow sheets to cascade off the top of the stack onto the stacker lift.
[0007] To solve problems associated with order change region scrap removal, diverter systems have been installed after the cutoff knife. These knife diverters have been problematic because the space between cutoff knife levels constrains the distance between top and bottom knife diverters, making jam clearing very difficult. Diverting small pieces, some of which may have diagonal cuts, is also very challenging.
[0008] Another means of achieving a gapless order change while accommodating redirection of the central portion of the web in the web slitter device from one level to the other using a plunge slitter/scorer with two slitter/score stations is taught in U.S. Pat. No. 6,137,381. In this patent, a means of partially severing transversely across the web at a position prior to the slitter/scorer is utilized. The partial web sever is comprised of a transverse slit extending inwardly from one lateral edge that severs at least a portion of the web representative of the larger of the total width of the running and new order widths of one of the upper or lower output web portions. The innermost running order and new order output webs of the other of said upper and lower output web portions remain at least partially uncut by said transverse slit.
[0009] The partial web sever order change will result in that portion of the old order web that is cut by the transverse slit to accelerate away from the new order due to cutoff knife overspeed as soon as the transverse slit exits the slitter/scorer. This old order output web will be of the exact width of the expiring order and will be cut to length with the exception of a short tail scrap piece that will fit onto the top of the stack. The output web that has not been severed may have a change in the number and width of the outs from the old order to the new order. To prevent a small piece of scrap from being created at the end of the last cuts in the old order on this web, the cutoff knife must be biased to cut upstream of the transverse cut on this last cut of the old order. This approach prevents a short scrap piece from being created that may jam up. When doing this, a sheet is created with a leading edge that is not square under certain circumstances. This can also cause a jam-up at the stacker.
SUMMARY OF THE INVENTION
[0010] In accordance with the present invention, a means of synchronizing the placement of the partial web sever in accordance with U.S. Pat. No. 6,117,381 relative to the cuts of the old order outs and the subsequent sensing of the web sever on the continuous web portion of the order change allows all of the scrap associated with the order change region to be slit to the exact width of the old order outs and cut to length that will fit on the top of the stack of the old order outs. The method of the present invention utilizes a shear apparatus that creates the transverse slit for the partial web sever order change based upon an algorithm that first places the web sever relative to the last cut in the order in the unsevered portion of the web such that the partial web sever lies within a distance greater than or equal to the maximum reaction of the cutoff knife profile controller (normally 18 inches) from the end of the order. This insures that a high-speed photo eve that is pre-positioned cross-corrugator to sense the web width change portion created by the partial web sever is able to provide a signal to the knife controller that allows the knife to cut on the web sever position to within very close accuracy.
[0011] Having determined that the partial web sever will be so positioned, the actual position of the partial web sever will then be chosen to correspond to the exact end of the order of the web portion associated with the shear sever. This approach will insure that the knife in the level with the continuous web will be able to synchronize upon width change sense to the end of the order and the level with web sever will be able to end the order upon the exact length of the sheets being cut. The result of this partial web sever shear and knife synchronization is that all of the order change segment scrap will be able to fit onto the top of the stack slit to the width of the outs on the level with the continuous web and the order with the partial web sever will also be slit to width and cut to the exact length of the sheets being cut on that level. The first sheets in the new order on both levels will normally have overlapping slits, making them scrap sheets. These sheets will protect the bottom of this stack and are normally considered scrap sheets at any rate.
[0012] The use of a photo eye to sense the width change on the continuous web portion in the order change region and the ability to synchronize the knife to cut on this width change position solves the problem of order change segment scrap not being of the width or length to go out onto the top of the stack on that level. The ability to synchronize the partial web sever position to the end of the order on that web with the partial web sever creates sheets of the same width and length on that level. The order change segment waste will therefore fit onto the top of the old order stack and at the bottom of the new order stack with scrap being of equal or less length and equal width of all outs being slit. There are no diagonal pieces, no small scrap pieces, and no over-width or over-length pieces than can cause jam-ups in the stacker or knife.
[0013] The invention as described can also be applied to solving the problem of ill-conditioned scrap associated with the center lateral cut implementation of U.S. Pat. No. 5,496,431. With the order change strategy described in that patent, webs going to both the upper and lower knife levels are continuous webs. At the order change region, there can be, and typically is, a change in the width and number of outs going to both knife levels. With the present invention, the lateral cut is synchronized with the last cut in the order of either the upper or lower knife level to place it so that it lies within a distance greater than, or equal to, the maximum reaction of the cutoff knife profile controller from the end of the order. This insures that a high-speed photo eye, prepositioned cross-corrugator so as to sense the web width change portion created by the center lateral cut, is able to provide a signal to the knife controller that allows the knife to cut on top of the center lateral cut to within very close accuracy.
[0014] Having determined that the center lateral cut will be so positioned, the actual position of the center lateral cut will then be chosen to either correspond to the exact end of the order of the alternative upper or lower web level or to a position upstream so that a high-speed photo eye that is pre-positioned cross-corrugator to sense the web width change position created by the center lateral cut on this web level is able to provide a signal to the knife controller that allows this knife level to also cut on the center lateral cut to within very close accuracy.
[0015] This strategy of placing the location of the center lateral cut by synchronizing it to the cutoff knife cuts and then subsequently sensing the web width changes in the upper and lower knife level webs to cut uniquely on the center lateral cut with the cutoff knife on both levels of web allows the scrap created in the order change region to be of the same width and number of outs so that all scrap can fit on top of the stack without jam-up.
[0016] The basic method of the present invention is applicable to a corrugator dry end in which a gapless order change is effected through the use of a plunge-type slitter-scorer. In such a corrugator, the conventional components include a slitter-scorer that is operable to provide longitudinal slit lines and score lines in a continuous corrugated paperboard web as it passes through the slitter-scorer. The slit lines divide the web into a plurality of output webs of selected widths. A pair of vertically separated cut-off knives downstream of the slitter-scorer receive the output webs and cut them into sheets of selected lengths. The knives typically include an upper knife and a lower knife, upstream of which is positioned a web selector device to selectively separate the output webs along a common innermost slit line into an upper output web portion and a lower output web portion for the respective upper and lower knives. The present invention, performed on a corrugator of the foregoing type, includes the steps of (1) determining an order change location in the web that defines the transition from a running (or old) order to a new order of a selected one of the upper and lower output web portions, (2) partially severing the web upstream of the web selector device to provide a generally transverse slit at the order change location, the transverse slit being positioned such that it will connect the common innermost slit line of the running order web portions and the common innermost slit line of the new order web portions as those slit lines are subsequently made downstream, (3) adjusting the slitter-scorer in an order change region of the web that includes the order change location to terminate the running order slit and score lines and to begin the new order slit and score lines, (4) after separating the output web portions, sensing a transverse edge of a web portion defined by the transverse slit and generating an edge location signal, and (5) operating one of the cut-off knives in response to the traverse edge location signal to cut one of the web portions on the line of the transverse slit.
[0017] When the method of the present invention is applied to an order change strategy described in U.S. Pat. No. 6,137,381, the step of partially severing the web comprises slitting the web from one edge to the farthest of the common innermost slit lines. The sensing step comprises sensing the transverse edge of the output web portion associated with the unslit edge of the web. The method may include the step of slitting the web from the edge nearest to said farthest of the common innermost slit lines. The step of partially severing the web preferably comprises slitting the web from the edge of the web containing the narrower of the upper and lower output web portions of the running order and new order output webs. In the preferred embodiment of this method, the sensing step comprises (1) mounting a laterally positionable sensor adjacent each upper and lower output web portion upstream of each respective knife, and (2) positioning the sensor between the innermost slit line of the selected running order and new order web portions. The mounting step preferably comprises mounting the sensor at a distance upstream of the respective knife at least as great as a distance comprising the product of a knife reaction time and a web speed.
[0018] When applied to an order change system of the type described in U.S. Pat. No. 5,496,431, the step of partially severing the web comprises slitting the web intermediate the opposite edges of the web. This method also preferably includes the steps of (1) sensing a transverse edge of the other web portion defined by the transverse slit and generating a second edge location signal, and (2) operating the other cut-off knife in response to said second edge location signal to cut the other web portion on the line of the transverse slit.
[0019] In accordance with a modified method for minimizing scrap in a gapless order change for a corrugator of the type described above, the method is particularly adapted to take into consideration the minimum length of sheets that the knives are capable of cutting and includes the steps of (1) determining an order change region in the web that defines the transition from a running order to a new order in which the common slit line separating running order upper and lower output web portions is offset laterally from the common slit line separating the new order upper and lower output web portions, (2) determining an order change location in the order change region for the last knife cut for each of the running order upper and lower output web portions, (3) partially severing the web upstream of the web selector device to provide a generally transverse slit in the order change region and at the order change location or upstream of the order change location by a distance at least equal to the minimum sheet length to subsequently connect the common slit line of the running order web portions and the common slit line of the new order web portions, (4) adjusting the slitter-scorer in the order change region to terminate the running order slit end score lines and to begin the new order slit and score lines, (5) after separating the output web portions, sensing a transverse edge of one of the output web portions defined by the transverse slit and generating an edge location signal, and (6) operating one of the cut-off knives in response to the edge location signal to cut an output web portion on the line of the transverse slit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is a schematic side elevation of a corrugator dry end modified to incorporate the apparatus and to practice the method of the present invention.
[0021] [0021]FIG. 2 is a schematic top plan view showing the order change sequence in a traveling paperboard web processed by the apparatus and method of the present invention.
[0022] [0022]FIG. 3 is a plan view of a rotary shear apparatus specially adapted for use with the method of the present invention.
[0023] FIGS. 4 - 6 are schematic top plan views of end of order knife cut strategies for the lower output web portions of the order change sequence shown in FIG. 2.
[0024] [0024]FIGS. 7 a - 7 d are schematic top plan views showing a modified order change sequence in which the partial web sever is made from the opposite edge of the web including the outs associated with the bottom level knife.
[0025] [0025]FIG. 8 is a perspective view of the lower level knife 24 shown in FIG. 1, including the photo eye detection system used to provide the synchronized order change strategy of the present invention.
[0026] [0026]FIG. 9 is a schematic top plan view of the order change shown in FIG. 2 illustrating system adjustments made to modify the end of order cuts to accommodate the minimum sheet length cut capability of the knives.
[0027] [0027]FIGS. 10 a and 10 b show an order change strategy similar to FIG. 2, but with a modified transverse slit provided in accordance with the teaching of another prior art method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring to FIG. 1, a continuous corrugated paperboard web 10 enters a corrugator dry end 11 from an upstream wet end (not shown) where the component webs are processed, glued together and cured for dry end processing. The dry end system shown is adapted to process order changes by using a gapless plunge type system of the present invention. While an order is running, the continuous web 10 passes through a slitter-scorer station 9 , including a slitting station 12 having two pairs of upper and lower slitting tools 13 and 16 , and a scoring station 15 having two pairs of scoring tools 14 and 17 . However, only one pair of slitting tools 13 and one pair of scoring tools 14 is in operative engagement with the web 10 while the order is being run, except for a brief period of overlap during order change. The other pairs of slitting tools 16 and scoring tools 17 are inoperative and, as shown, are withdrawn from operative contact with the web. In the slitting station 12 and the scoring station 15 , the web 10 is provided with longitudinal score lines (not shown) and longitudinal slit lines 18 , which are shown schematically in various order patterns in the webs of FIGS. 2 , 4 - 7 , 9 and 10 . The continuous longitudinal slits 18 define a series of output webs or outs 20 which continue downstream into a cut-off knife 21 where the webs are cut into selected length sheets 22 . The sheets 22 are conveyed downstream into a stacker (not shown) or other suitable collecting device.
[0029] In the system shown in FIG. 1, a two level or duplex cut-off knife 21 includes an upper cut-off knife 23 and a lower cut-off knife 24 . Each of the knives 23 and 24 is capable of processing any arrangement of outs 20 up to the full width of the web 10 . However, two cut-off knives are typically utilized to enable two independent sheet orders to be processed simultaneously, where the sheet lengths and widths may vary considerably between running orders. Thus, one set of upper output web portions 25 is directed to the upper cut-off knife 23 and a set of lower output web portions 26 is directed into the lower cut-off knife 24 . The output webs 20 exiting the slitter-scorer station 9 are separated vertically in a web selecting device 27 in which selectively positionable forks in an array extending across the full width of the web 10 are positioned to direct the respective upper and lower output web portions 25 and 26 to the correct cut-off knife 23 or 24 . The forks in the web selector 27 are thus selectively positioned to direct the respective output web portions 25 and 26 onto upper and lower slider tables 19 and 29 which support the outs and direct them into their respective knives 23 and 24 . In FIG. 2, for example, the current running order 28 is comprised of a single upper output web 25 also identified as U 1 and a pair of lower output webs 26 , each identified as L 1 . Furthermore, the FIG. 2 example shows that an order change will result in an immediately following new order 30 comprising a single upper output web U 2 , substantially wider than running order output web U 1 , and a pair of lower output webs L 2 , each narrower in width than either of the running order lower output webs L 1 .
[0030] In the schematic system shown in FIG. 1, an upstream rotary shear 32 is shown for use in a gap-type order change or a plunge style order change system. Shear 32 incorporates a unique construction and, as schematically shown in FIGS. 3 a and 3 b , is comprised of upper and lower solid non-rotating center shafts 57 , around which two pairs of upper and lower cylindrical shells 56 a and 56 b are rotatably carried. Thus, each cylindrical shell 56 a or 56 b , coaxially mounted on one shaft 57 , is carried by an outer bearing 53 a or 53 b and an inner bearing 54 a or 54 b . In this manner, each cylindrical shell 56 a and 56 b can be rotated independently of the other. The axial space between adjacent cylindrical roll shells 56 a and 56 b can be made very small, i.e. 0.0125 inch (3 mm) or less. Separate motors 55 a and 55 b drive respective shell pairs 56 a and 56 b . The shell pairs 56 a and 56 b are provided with helical knife blades 58 a and 58 b , respectively, to partially or fully sever the web 10 running through the shear 32 . Motors 55 a and 55 b can be electrically timed and servo-controlled so that both cylinder pairs 56 a and 56 b can be powered to completely sever web 10 across its full width for a gap-type order change. Alternately, control signals can be generated to activate only motor 55 a operating upper and lower cylinder pair 56 a or motor 55 b operating upper and lower cylinder pair 56 b to create a partial web sever in the form of the transverse slit 33 shown in FIG. 2. The sum of the cross machine width of shear cylinders 56 a and 56 b is wider than web 10 and, preferably, the shear 32 can be side shifted on tracks 59 so that the transverse slit (e.g. 33 ) can be made slightly more than half the width of web 10 . The space between cylinder shells 56 a and 56 b can be directly aligned from the upper knife to the lower, or axially offset. Also, the cylinder pair 56 a and 56 b could be locked together for simultaneous cutting either electrically by synchronizing the servomotor drives or by selectively mechanically locking the cylinders together (and using a single motor 55 ). By using two motors, a partial web sever could be effected on either side of the shear. Using one motor, allows a partial sever to be made on only the driven side of the shear. The knife blade pairs 58 a and 58 b may be provided with continuous cutting edges or may comprise serrated blades.
[0031] In an alternate arrangement, two rotary shears (not shown), each capable of cutting in from an opposite edge of the web by slightly more than half the width of the web, could be used to create a partial web sever from either side of the web. Such separate shears would be located offset from each other in the direction of web travel. The transverse slit 33 of FIG. 2 defines the approximate longitudinal center of an order change region 34 where the slitting and scoring tools 13 and 14 operating on the running order 28 are retracted and the slitting and scoring tools 16 and 17 , preset to handle the new order 30 , are “plunged” into operative engagement with the web 10 . Thus, as shown in the center transitional view in FIG. 2, the order change region 34 , carrying the transverse slit 33 , exits the slitter-scorer with overlapping slit lines 18 from the running order 28 and the new order 30 . This region will also include overlapping score lines (not shown) from the running and new orders.
[0032] The substantial increase in width of the upper output web U 2 in the new order 30 from the upper output web U 1 of the running order 28 requires that a portion 39 of the width of the immediately adjacent output web L 1 of the running order 28 be diverted from the lower knife level 24 to the upper knife level 23 in order to effect the order change. The transverse slit 33 provides a break in the web 10 which allows the selector forks in the web selecting device 27 to be repositioned to redirect the web portion 39 defining the transition from running order web L 1 to new order web L 2 However, a portion 43 of innermost running order web L 1 is not severed by the transverse slit 33 and is connected to the innermost output web L 2 of the new order 30 . The order change is, therefore, effected at the slitter-scorer with no gap and with a continuous web (output web portions L 1 and L 2 ) into the lower cut-off knife 24 .
[0033] In the righthandmost transitional view of FIG. 2, the transverse slit 33 may be synchronized exactly with the end of the running order 28 such that the tailout end 35 of running order output web U 1 coincides with the slit 33 . A gap 36 between the transverse slit 33 and the tailout end 35 is formed as web U 1 accelerates away from web U 2 as a result of the overspeed of the pull roll at downstream knife 23 . However, because it will normally not be possible to also attain exact synchronization of the transverse slit 33 and the subsequent knife cut defining the end of the order for the lower output webs L 1 , an alternate end of order knife cut strategy needs to be considered. This is shown in FIGS. 4, 5 and 6 which are taken from FIG. 2, but show only the lower output web portions L 1 and L 2 of the running and new orders 28 and 30 , respectively. In these figures, the running order and new order sheet lengths provided by the downstream lower cutoff knife 24 , are defined by the transverse dash lines and are designated, respectively, S 1 and S 2 . It is important to assure that the end of order knife cut 70 (defining the transition from sheets S 1 to S 2 ) is biased to assure that it occurs upstream of the transverse slit 33 . This is shown in FIG. 4. Otherwise, if the knife cut defining the tailout end of running order webs L 1 is biased to the downstream side of slit 33 , as shown in FIG. 5, a short scrap piece 72 would be cut in the tail of the innermost output web portion L 1 of the running order that could result in a jam-up.
[0034] Depending upon the relative widths and numbers of outs in the running and new orders, scrap pieces or ill-conditioned leading edges of new order pieces can be created that jam the knives or the downstacker during the order change process. For example, FIG. 7 a shows an order with a single output web U 1 to the upper level knife 23 and two output web portions L 1 to the lower level knife 24 on the running order 45 . Correspondingly, there are two output web portions U 2 to the upper level knife and one output web portion L 2 to the lower level knife on the new order 46 . In this example, the partial web sever provided by transverse slit 44 is taken in a manner to completely sever the lower output web portions L 1 while leaving a continuous web directed to the knife in the upper level. FIGS. 7 b - 7 d show only the upper output web portions U 1 and U 2 of the running new orders, respectively. In these Figures, the running order and the new order sheet lengths, provided by the downstream upper cutoff knife 23 , are defined by transverse lines and are designated, respectively, S 1 and S 2 . In FIG. 7 b , the end of order knife cut 76 occurs downstream of the transverse slit 44 . The first sheet S 2 in the new order 46 located at the innermost position in the new order output web portion U 2 , has a protuberance 81 that may cause this sheet S 2 to skew when it hits the back stop of the stacker, causing a stacker jam-up. In FIG. 7 c , the end of order knife cut 77 occurs upstream of the transverse slit 44 . Knife cut 77 creates a small piece 83 which will go into the stacker with the last sheet S 1 of the running order output web U 1 . Since there is no stack onto which this small piece 83 can be stacked in the downstacker, it will drift down alongside the stack of sheets S 1 into the stacker lift, become wedged between the lift rollers and cause ajam-up. Alternately, small piece 83 could jam-up in the cutoff knife 23 .
[0035] As illustrated by the foregoing examples, there is a high potential for jam-up if the last cut in the running order on the continuous web portion U of the order change either leads or lags the partial web sever defined by the transverse slit 44 . These problems are alleviated by synchronizing the last cut in the running order U 1 with the partial web sever transverse slit 44 .
[0036] Referring again to FIG. 6 which shows the end of order transition between the lower output web portions L 1 and L 2 in FIG. 2, the last cut 73 in the running order L 1 is synchronized with transverse slit 33 , resulting in scrap pieces 71 and 72 that are slit to the exact width of running order sheets S 1 and are of a length shorter than running order sheets S 1 , so that they fit onto the top of the stacks created in the down stacker.
[0037] Comparing the foregoing end of order synchronization with that described above for the order change problems described with respect to FIGS. 7 b and 7 c , FIG. 7 d shows an end of order synchronization in accordance with the present invention. In FIG. 7 d , running order last cut 78 is synchronized with transverse slit 44 , resulting in a scrap piece 79 that is slit to the exact width of the running order sheets S 1 in the upper output web portion U 1 and cut to a length shorter than running order sheets S 1 , so that it will fit onto the top of the stack in the downstacker. New order sheets S 2 are also cut squarely so that they will fit against the downstacker backstop without skewing (as would occur in the FIG. 7 b situation previously described).
[0038] The apparatus required to synchronize the last cut 78 in FIG. 7 d or 73 in FIG. 6 with the transverse slit 44 or 33 , respectively, defining the order change location is a high speed photocell 61 shown in FIG. 8. The description of the FIG. 8 apparatus which follows will utilize the order change scheme shown in FIG. 6 wherein the lower output web portions L 1 and L 2 are directed to the lower cutoff knife 24 . The high speed photocell 61 is mounted on a transverse positioning track 63 in knife 24 (it being understood that an identical photocell system may also be mounted on upper cutoff knife 23 for use when the last order change cut is effected at that level). The photocell 61 is moved prior to order change by a positioning motor 62 to a transverse position along track 63 such that it can detect an edge of the web defined by the transverse slit 33 which defines a transition from board to no board (or in the FIG. 7 d order change scheme, from no board to board) as the order change region progresses through the cutoff knife. The cutoff knife controller 65 receives an input signal from high speed photocell 61 and causes a change in the profile control outputs to knife motor 66 such that the knife cuts on line 73 exactly coincident with the transverse slit 33 . A problem associated with controlling the knife to cut precisely on transverse slit 33 is that there must be a minimum distance 69 between the next-to-last sheet cut 70 and the last sheet cut 73 , so that the knife can react quickly enough to synchronize the cut 73 with transverse slit 33 .
[0039] To ensure that this synchronization is possible, it is necessary to place transverse slit 33 relative to the second-to-last cut 70 by having the system controller 65 “look ahead” in the order as shown in FIG. 9. FIG. 9 shows phantom cut lines associated with the running order 28 for the upper output web portion U 1 and the lower output web portions L 1 as they will subsequently occur in the respective cutoff knives 23 and 24 as the end of the order approaches the knives. In FIG. 9, cut line 91 defines the nominal order end based on the requirement to make N cuts (S N sheets) in upper level output web portion U 1 . If the transverse slit 33 had been placed to coincident with cut line 91 , then the distance from the next-to-last sheet cut 96 on the lower output webs L 1 and the last sheet cut 91 on the upper output web U 1 would have been distance 92 . This distance is too small to have allowed the lower level knife 24 to react quickly enough to a signal from photocell 61 to cut on cut line 91 . To provide adequate reaction time, the transverse slit 33 could be placed to coincide with upper order cut line 95 in which case the upper level running order would be overrun by one sheet S N+1 . In that case, the distance from the next-to-last cut line 96 to the last cut line 95 would be distance 93 , nearly a full sheet length L 1 on the lower level running order. Over running the order by a second sheet S N+2 would place the transverse slit 33 , as shown in FIG. 9, with a distance between the next-to-last cut line 70 and the transverse slit 33 equal to the length 94 . This length would exceed that required for the reaction time of lower cutoff knife 24 to respond to sensing an edge of the web defined by transverse slit line 33 by the high speed photocell 61 , so that the final cut 73 on the lower level running order web could be placed to coincide with the transverse slit 33 . Length 94 would also be substantially less than length 93 and would be chosen to minimize the length of the last sheets, which constitute waste sheets, in lower level running order L 1 .
[0040] Other criteria could be used for choosing placement of the transverse slit line 33 relative to the phantom cut lines shown in FIG. 9 of the running upper and lower output web portions U 1 and L 1 , if such criteria are consistent with the overall objective of insuring that the high speed photocell 61 can sense the web width change (e.g. at 33 in FIG. 8) between the running and new orders and subsequently cause the last cut 73 on the continuous web portion L 1 of the order to be coincident with the transverse slit line 33 defining the order change location so that all waste sheets at the end of the order are slit to the width of the running order such that jam-ups due to waste sheets at order change are eliminated and that the length of these waste sheets is minimized.
[0041] The apparatus and methods described herein for minimizing waste at order change and avoiding odd shaped or small size scrape pieces that can cause jam-up at order change applies as well to order changes made using the methods described in U.S. Pat. No. 5,496,431. The order change pattern of FIG. 2 is shown in FIGS. 10 a and 10 b with a transverse slit 133 placed in the interior of the order change region as taught in the above identified patent. With this order change strategy, both upper and lower output web portions U and L are continuously threaded up to their respective upper and lower knife levels. The web directed to the lower knife level would look exactly as that shown in FIGS. 4, 5 and 6 . Placement of the transverse slit relative to the phantom cut lines in the running order web portions would be accomplished in the same manner described for placement of transverse slit lines 33 or 44 described above. For this embodiment of the invention, a high speed photo cell similar to photocell 61 in FIG. 8 would also be located in the upper level knife 23 . This photocell would be positioned transversely across the knife to sense the web width discontinuity created by transverse slit 133 at the order change location as shown in FIG. 10 b . The transverse slit would normally (but not necessarily) be placed coincident with the last cut in the upper level running order U 1 . That being the case, the knife would have reaction time to respond to the web width transition detected by the high speed photocell and cause the last cut of the running order to be placed coincident with the transverse slit 133 . This would ensure that there were no small pieces that were outside the width of the running order that could cause knife or stacker jam-up. | A system is provided for synchronizing the end of order cutoff for a plunge slit order change on a corrugator that minimizes scrap and cuts the end order sheets to a length and width such that jam-ups at order change are eliminated. The system detects a transverse edge discontinuity immediately prior to end of order cutoff and, in conjunction with a prior calculation comparing sheet lengths and order end positions between upper and lower webs, positions an upstream transverse partial web slit at an optimum order end position such that the entire web is ultimately cut on the partial sever at an optimum position for scrap minimization and scrap sheet size and shape. | 8 |
TECHNICAL FIELD
This invention relates to systems that employ vacuum pressure for holding print media as the media is advanced through a hard copy device such as a printer.
BACKGROUND AND SUMMARY OF THE INVENTION
An inkjet printer includes one or more ink-filled pens that are mounted to a carriage in the printer body. Normally, the carriage is scanned across the width of the printer as paper or other print media is advanced through the printer. Each ink-filled pen includes a printhead that is driven to expel droplets of ink through an array of nozzles in the printhead toward the paper in the printer. The timing and nominal trajectory of the droplets are controlled to generate the desired text or image output and its associated quality.
As the sheet of print media is advanced through the printer, it must be secured so that high-resolution printing can occur. One method of holding the sheet is to direct it against an outside surface of a moving carrier such as perforated drum. Suction is applied to the inside surface of the carrier for holding the sheet against the moving carrier. The carrier is arranged to move the sheet into and out of a location adjacent to the pens that apply the ink to the sheet.
It is important to apply the proper level of suction to a system like the one just described. The suction, or vacuum pressure (here the term “vacuum” is used in the sense of a pressure less than ambient), must be applied at a level sufficient for ensuring that the sheet of print media remains in contact with the carrier. For example, should the edges of the sheet lift from the carrier as a result of too little vacuum pressure, there is a likelihood that the pen will collide with the edge, which is quite undesirable. Also, the vacuum pressure level must be high enough to hold the sheet flat, to eliminate wrinkling or cockling of the sheet during printing.
If the vacuum pressure level is too high, the surface of the sheet may become deformed in the vicinity of the perforations. As a result, the ink droplets will not strike the surface of the sheet as intended, and print quality will suffer. Also, power is wasted if the vacuum level is unnecessarily high.
Moreover, when liquid ink is applied to the sheet, it is important to ensure that the vacuum pressure level is not so high as to draw the ink completely through the sheet, such that the ink appears on the other side as an undesirable effect known as “strike through.”
The foregoing considerations concerning vacuum levels are complicated by differences in the physical characteristics of the variety of print media that can be handled by modern printers. The print media can be thin, relatively lightweight cut paper, relatively thick or stiff media known as transparencies, heavy photo stock, etc. Also, media having the same thickness will not necessarily deform by the same amount for a given vacuum pressure level. For example, a sheet of transparency type media having a given thickness will not deform by the same amount as a sheet of paper having the same thickness. In short, one level of vacuum pressure will not be appropriate for the wide variety of print media available to a user.
The present invention is directed to a system for controlling or regulating the vacuum hold pressure in a printer based upon the sensed stiffness of the print media that is directed through the printer.
In one preferred embodiment of the invention, the deflection of the print media is sensed before or as the media reaches the carrier. The vacuum pressure level is regulated in response to this deflection measure, thereby to have applied to that particular media a level of vacuum pressure that is best (remove cockle, avoid strike through, etc.) for that media.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a print media carrier of a printer, which carrier is adaptable for use with the vacuum-hold control system of the present invention.
FIG. 2 is a side view of the media carrier, including media handling and sensing components of the present invention.
FIG. 3 an enlarged view of a media stiffness sensing station component of the present invention.
FIG. 4 is a block diagram of the present system.
FIG. 5 is a side view of the media carrier depicting an another preferred embodiment of a media stiffness sensing station of the present invention.
FIG. 6 is a diagram of another preferred embodiment of a media stiffness sensing technique in accord with the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIGS. 1 and 2, one preferred embodiment of the present invention is operable with a printer media carrier, such as a drum 20 , that is supported by a shaft 22 within a printer. The drum 20 preferably has a circumference of about 50 cm, although any of a variety of drum sizes will suffice.
An endless drive belt 24 engages a gear 28 that is fixed to one end of the drum 20 . That belt also engages a drive pulley 26 (FIG. 2 ). In a preferred embodiment, a motor (not shown) continuously drives the pulley 26 to rotate the drum whenever a printing operation is carried out.
The other end of the drum shaft 22 is hollow. A vacuum line 30 enters the hollow interior of the drum 20 through the shaft 22 . The shaft has openings inside the drum to enable fluid communication between the end of the vacuum line and the drum interior. The other end of the vacuum line 30 is connected to a regulated vacuum system 35 (FIG. 4 ).
The vacuum is applied to the interior of the drum as a mechanism for securing print media, such as a sheet of paper 32 , to the drum 20 as the paper is advanced through the printer over the drum. To this end, the drum is perforated with vacuum ports 34 that extend between the interior surface 25 of the drum and the outer surface 36 of the drum. The suction present in the ports 34 secures to the drum outer surface 36 the paper 32 that is directed into contact with the drum, as is described next.
FIG. 2 illustrates in somewhat simplified fashion a portion of the path of the paper 32 through the printer. It is noteworthy here that although the print medium will be hereafter referred to as “paper”, any of a number of materials can be used as the medium in such printers, such as thin, relatively lightweight cut paper, relatively thick or stiff media known as transparencies, heavy photo stock, etc. As will be described, the present invention provides for regulating the vacuum system 35 so that a level of suction is applied by the vacuum system to match the physical characteristics of the paper; namely, the stiffness of the paper.
The paper 32 is picked from an input tray and driven into the paper path in the direction of arrow 40 . The leading edge of the paper is fed into the nip between a drive roller 42 and an idler or pinch roller 44 . Upon exiting the rollers 42 , 44 , the paper moves across a station 41 that senses the stiffness of the paper as described more fully below. From there the paper 32 is driven in a controlled manner into contact with a curved guide 46 that, in cooperation with guide rods 48 , directs the leading edge of the paper 32 into tangential contact with the exterior surface 36 of the drum 20 .
As the vacuum ports 34 of the drum rotate into contact with the paper 32 , the suction established between the paper and drum secures (“loads”) the paper to the drum, and the drum continues to rotate in the direction of arrow 50 . The guide rods are retracted from contact with the paper as soon as the paper is loaded. The paper 32 on the drum is moved to a location adjacent to one or more pens 52 of the printer. The pens are controlled to apply ink to the paper during a printing operation.
Once the printing operation respecting a particular sheet of paper is complete (the paper may be rotated past the pens several times to complete the operation) the paper is removed from the drum. This can be carried out by the controlled, temporary movement of guide prongs 21 (FIG. 2) that pivot about a post 23 into circumferential grooves 37 that are formed in the drum. This redirects the paper from the drum to a conveyor belt 39 that delivers the paper to a collection tray.
In one preferred embodiment of the present invention, the thickness of the paper 32 may be detected just before the paper 32 reaches the station 41 . To this end, a lever 54 is connected at one end to the shaft 56 of the pinch roller 44 . The lever has pivotally connected between its ends a pivot 58 , which is a fixed point relative to the printer. The remote end 60 of the lever has mounted to it an electrode 62 that faces another electrode 64 that is aligned with the first electrode 62 and is mounted to a fixed, electrically insulated pad 66 in the printer.
A deformable, conductive member 68 is located between and in contact with the two electrodes 62 , 64 . The member 68 is made of conductive rubber in which the electrical conductivity changes in proportion to the pressure applied to it. In this regard, a low voltage is applied via lead 75 to the movable electrode 62 by the vacuum controller 80 (FIG. 4 ). The controller is discussed more below. Another lead 76 connects the fixed electrode 64 with the vacuum controller. Thus, the magnitude of the signal appearing on line 76 to the vacuum controller corresponds to that applied on line 75 , as affected by changes in the shape (i.e., conductivity) of the deformable member 68 .
As the leading edge 70 of a sheet of paper 32 passes between the drive roller 42 and the pinch roller 44 , the pinch roller 44 is lifted (arrow 72 ) by an amount corresponding to the thickness of the paper. As a result, the lever 54 rotates about pivot 58 such that the remote end 60 of the lever moves downwardly (arrow 74 ) and compresses the conductive member 68 . The attendant change in the conductivity of the member 68 varies the signal appearing on line 76 (hereafter referred to as the thickness signal) to the vacuum controller 80 . The location of the pivot 58 is selected to multiply the distance of roller 44 movement by an amount sufficient to provide measurable changes in the compression of the conductive member 68 .
As the paper 32 passes across the station 41 a measure of its stiffness is made and provided to the vacuum controller 80 . In this regard, the paper is deliberately deflected at the station 41 and a non-contact-type sensor 43 senses the amount of deflection. The particulars of one embodiment of the station 41 are best considered in connection with the detail view of FIG. 3 .
The paper 32 is moved across the surface 45 of a platform 47 that makes up part of the station 41 . The platform is the upper wall of an elongated, substantially hollow, bar-like member that extends across the width of the paper, perpendicular to the path of the paper. The underside of the station has at least one tubular stub 49 (FIG. 2) that is in fluid communication with the hollow interior of the station. The other end of the stub 49 is connected to a vacuum line 51 that connects (FIG. 4) with a constant level vacuum source that is discussed more below.
The vacuum pressure in the station 41 is communicated via one or more ports 53 to a channel 55 that is recessed in the surface 45 of the platform 47 (FIG. 3 ). The channel can be any of a variety of shapes, and need not extend across the width of the paper. In one preferred embodiment, the channel is generally rectangular, with its long sides extending in a direction parallel to the width of the paper 32 (i.e., into the plane of FIG. 3 ). The depth of the channel 55 (that is, the depth of the recess from the surface 45 ) is preferably about 10 to 12 mm. As noted, many other channel sizes will suffice for permitting deflection of at least part of the paper.
While part of the advancing paper 32 spans the channel 55 , the suction in the channel causes the paper to deflect from the generally planar orientation (shown as dashed line 57 ) it would assume in the absence of the applied suction. The sensor 43 is located adjacent to the channel 55 and senses the amount of deflection of the part of the paper that spans the channel.
In particular, the non-contact type sensor 43 may be an optical type, including a light emitter 59 and an array of light detectors 61 . The emitter 59 and detectors 61 are spaced apart. Light is directed via a beam 63 to be incident on the center of the channel, thereby to be reflected from the paper 32 . Depending upon the amount of deflection of the paper 32 , different ones of the array of detectors 61 will receive different amounts of light reflected from the paper. (Alternatively, a single light detector would receive a different amount of light, depending upon the amount of paper deflection.)
For instance, when the paper is deflected as shown in FIG. 3, the reflected light beam 65 strikes a different area in the light detector array than does a beam 67 that is reflected from a non-deflected surface 57 of the paper 32 . Thus, different values of an output signal (hereafter referred to as the stiffness signal) will appear on the output lead 69 of the sensor 43 , which signal is provided to the vacuum controller 80 .
The vacuum controller 80 monitors the stiffness signal, as well as the above-described thickness signal, and adjusts the level of vacuum applied to the drum via line 30 . In this regard, the vacuum controller 80 may be incorporated into the overall printer controller and include suitable analog to digital converters for receiving and processing the just described stiffness and thickness signals.
The vacuum controller 80 is also provided with suitable drivers for controlling via line 82 a conventional electronically controlled pneumatic valve 84 . The valve 84 is connected to the vacuum line 30 that extends between a constant level vacuum source 88 and the drum 20 . The valve 84 is also interconnected between the line 30 and an atmospheric vent 90 . The valve is controlled by the controller 80 (as noted, in response to the thickness and stiffness signal) to open the vent 90 by an amount sufficient to alter (lower) the vacuum pressure in the line 30 , hence in the interior of the drum 20 . In this regard, the vacuum controller includes a look-up table or the like to correlate the stiffness signal and the thickness signal to the desired valve adjustment. This table can be empirically derived through tests of various media types.
One of ordinary skill will appreciate that there are many other ways available for adjusting the vacuum level applied to the drum. For instance, the vacuum source itself could be controllable (such as be varying fan speed) to increase or decrease the level as needed in response to the stiffness signal and the thickness signal.
Although separate thickness measuring mechanisms (lever 54 , electrodes 62 , 64 etc.) were described earlier, another preferred embodiment of the present invention employs the components associated with the station 41 to serve a dual purpose of measuring thickness of the paper 32 in conjunction with the stiffness (i.e., deflection) of the paper, thereby eliminating the need for separate mechanisms for measuring these two paper characteristics.
With particular reference to FIG. 3, the thickness of the paper 32 can be measured by the sensor 43 while no vacuum pressure is applied to the channel 55 (hence the uppermost surface of the paper 32 takes the planar orientation shown at 57 ). In this regard, the sensor may be first calibrated in any of a number of ways, such as by sensing the non-deflected thickness of a paper having a known thickness.
Calibration of the sensor is not required. That is, a true thickness measure is not required for the vacuum control aspects of the present invention. The comparison of the measurements of the non-deflected paper surface (vacuum off) and of the deflected surface (vacuum applied) suffices for controlling the vacuum level. Thus, even though the sensor output signal corresponding to the non-deflected paper surface is characterized as a “thickness” signal, one will appreciate that the thickness of the paper need not, in fact, be determined to implement this embodiment of the present invention.
As mentioned, the deflection of the paper is measured after the vacuum pressure is applied (via the source 88 through vacuum line 51 ) to the channel 55 . In short, the vacuum pressure is cycled off and on during the time a particular sheet of paper spans the channel 55 . To this end, the vacuum line 51 that extends from the vacuum source to the station is equipped with a electronically controlled valve 81 (FIG. 4) that is opened and closed by the vacuum controller 80 via control line 83 . The valve 81 vents the line 51 to atmosphere when that valve is closed. Suction is applied to the line (hence to the channel 55 ) when the valve is opened.
Thus, for a given sheet of paper, a reflected light beam 67 (refer to FIG. 3) received on the detectors of the array 61 while the vacuum pressure in the channel is absent (i.e., valve 81 is closed) represents the thickness (or location of the non-deflected surface) of the paper, and a reflected light beam 65 received on the detectors of the array 61 while the vacuum pressure in the channel is present (i.e., valve 81 is open) represents the deflection of the paper. Therefore, the signal appearing on the sensor output lead 69 varies in time between the above defined thickness signal and stiffness signal.
It will be appreciated that, as another alternative, a separate, non-contact type sensor 43 could be employed as a paper thickness-measuring sensor. That is, a sensor otherwise like that 43 shown in FIG. 3 could be located adjacent to the platform 47 away from the channel 55 so that the part of the paper 32 underlying that second sensor remains supported on the surface 45 of the platform. As a result, only a paper thickness signal is generated by that second sensor.
FIG. 5 represents an alternative approach to the present invention whereby the deflection station is incorporated into the paper carrier component of the system. In this embodiment, the carrier is a drum 120 in which one of the flat end walls 85 is stationary. The curved surface 136 of the drum is sealed to but rotatable around the periphery of that wall 85 . The other end wall of the drum is connected to a shaft and pulley arrangement for rotating the drum in a manner as described above.
A pair of partitions 87 divides the interior of the drum 120 into two sectors. The partitions are rigid plates that are fixed to the end wall 85 . The inner radial edges of the partitions are formed of resilient, low friction material that makes a sealing engagement with, and slides along, the rotating shaft 122 . The outer radial edges of the partitions similarly slide against the inner surface 125 of the carrier 120 .
An inlet port 89 extends through the end wall 85 between the partitions 87 . That port 89 is connected with the vacuum line 51 (FIG. 4.) As a result, the sector 91 of the drum interior is provided with a relatively high level of suction that, as will be explained, is useful for both loading the paper 132 onto the drum 120 and for measuring the thickness and stiffness of that paper.
In response to the thickness and stiffness measure, the controller 80 controls the vacuum applied to the other sector 93 of the drum interior. That other sector 93 is the one underlying the pens 152 of the printer and, therefore, the vacuum level within that sector 93 is controlled or regulated to remain within the desired range discussed above for removing cockle, avoiding strike through, etc., for the particular sheet of paper 132 .
As shown in FIG. 5, the surface 136 of the drum 120 is provided with groups of ports and channels 155 that substantially match the port 53 and channel 55 made in the platform 47 of the previously described station 41 (FIG. 3 ). In one preferred embodiment, groups of the ports and channels 155 are spaced apart and distributed evenly around the surface 136 of the drum.
A sensor 143 that substantially matches the earlier-described sensor 43 is mounted to the printer and located outside the high-vacuum sector 91 . The light emitter of this sensor is directed toward the drum surface and, therefore, applies on its output a stiffness signal whenever a channel 155 (with paper spanning the channel) passes next to the sensor 143 .
The controller 80 receives the stiffness signal from the sensor 143 . Also as the channel 155 is rotated away from the sensor 143 , the beam emitted by the sensor strikes a non-deflected part of the paper 132 . Thus, the sensor output alternates between the stiffness signal and the thickness signal. For a given sheet of paper, the controller treats the received signal having the greater magnitude (most deflection) as the stiffness signal and the other as the thickness signal. In instances where no paper is carried by the drum, the signal returned by the sensor is outside of a predetermined threshold (which threshold is established by a calibration process using an empty drum) and the signal is ignored.
The stiffness and thickness signals are then processed as described above to control the vacuum level in the sector 93 of the drum underlying the pen 152 . In this regard an inlet 101 is provided through the end wall 85 and connected to the vacuum line 30 (FIG. 4 ). The suction level in sector 93 , therefore, is controlled in a like manner as that of the drum interior as described above in connection with the earlier embodiment.
It will be appreciated that in the just described embodiment (FIG. 5) the high level of vacuum pressure applied to the sector 91 where the paper 132 is first brought into contact with the drum 120 is useful for ensuring that the paper is properly drawn (loaded) onto the drum. This is in addition to the use of the high-level vacuum pressure for deliberately deflecting the paper to obtain the stiffness measure.
Although a non-contact type deflection mechanism and sensor is preferred, it is contemplated that other mechanisms may be employed. For instance, a contact type mechanical probe and associated sensor is shown as an alternative embodiment in FIG. 6 .
The embodiment of FIG. 6 employs a platform 99 that substitutes for the platform 47 described above. No vacuum pressure is applied to this platform. Rather, a single channel 101 is formed in the upper surface 103 of the platform. The paper 32 is directed across this surface 103 . An elongated probe 105 is normally suspended above the channel 101 . In one embodiment a ferromagnetic part 107 of the probe is held against an electromagnet 109 , that is turned on and off by the printer controller. When the electromagnet is tuned off (which occurs while the paper is beneath the probe), the probe 105 is released and moves toward the paper in a vertical path defined by annular guide members 111 .
The probe weight deflects the paper 32 as the tip of the released probe contacts it. The amount of paper deflection (relating to the overall distance that the probe travels) is measured as described next.
An optical sensor 100 measures the probe movement in deflecting the paper. The upper end 113 of the probe carries a plate 102 . The plate has a surface 104 that faces the emitter 106 (such as an infrared emitter) and detector 108 (such as a photodiode) of the optical sensor 100 . The surface 104 is coated with reflective material in a pattern where the width of the material, hence the intensity of the emitter light reflected back to the detector, varies in the direction of movement of the probe end 113 (up and down in FIG. 6 ). As a result, the output from the sensor 100 , which is applied to the vacuum controller (the stiffness signal) varies with the probe movement, which, as described, correlates to a preferred vacuum pressure level to be applied to the drum interior. It will be appreciated that many other mechanical type sensors can be used to deflect the paper and quantify the deflection in a manner such as just described.
Although preferred and alternative embodiments of the present invention have been described, it will be appreciated by one of ordinary skill that the spirit and scope of the invention is not limited to those embodiments, but extend to the various modifications and equivalents as defined in the appended claims.
For example, there may be fewer or more perforations or channels in the drum as compared to what is depicted in the drawings. Also, the drum need not be a rigid, cylindrical member. For instance, the drum may be more like a porous conveyor belt of any given configuration. | A system for regulating the vacuum hold pressure in a printer based upon the stiffness of the print media that is directed through the printer. In one embodiment, the stiffness of a sheet of media is detected before or as the sheet reaches the carrier. The vacuum pressure level is thus regulated in response to the stiffness measurement of the sheet, thereby to have applied to that particular media a level of vacuum pressure that prevents problems that arise when pressure levels are too low (for example, inadvertent shifting of the paper) or too high (for example, paper deformations that reduce print quality). A sensing technique for alternatively sensing stiffness and paper thickness is also provided. | 1 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/016,050, filed Dec. 21, 2007, which is incorporated herein by reference in its entirety.
FIELD
[0002] The present disclosure relates to high purity apparati, e.g., magnetic hard disk drives, and more specifically, to coatings for particle reduction in such apparati.
BACKGROUND
[0003] In magnetic disk drives and other high purity applications, particle contamination can cause a host of failure mechanisms. In these applications, it is highly desirable to minimize particles present in manufacturing and during application. Magnetic disk drives typically comprise a number of precisely dimensioned operating parts, e.g., spacers, disk clamps, e-blocks, cover plates, base plates, actuators, voice coils, voice coil plates, etc. These components can all be potential sources of particles. During drive operation, the head typically flies over the media at a spacing of about 100 Å. This spacing is decreasing with increasing areal density, making the reduction and prevention of particle generation ever more critical. Particles at the head disk interface can cause thermal asperities, high fly writes, and head crashes; any of these are detrimental to performance of a disk drive.
[0004] U.S. Pat. Publ. No. 2003/0223154 (Yao) discloses prevention of particle generation by encapsulation with a coating “made of a soft and tenacious material, such as gold, platinum, epoxy resin, etc.” U.S. Pat. Publ. No. 2002/0093766 (Wachtler) discloses the use of adhesive-backed heat shrinkable conformal films to protect against particle generation. U.S. Pat. No. 6,671,132 (Crane et al.) discloses the use of metal or polymeric coatings. U.S. Pat. No. 7,035,055 (Kikkawa et al.) discloses the use of resin coatings. U.S. Pat. No. 6,903,861 (Huha et al.) discloses the use of certain polymer coatings as an encapsulant for microactuator components. PCT Publ. No. WO 2006/074079 (Kehren et al.) discloses the use of fluoropolymers comprising reactive pendant groups for particle suppression coatings.
[0005] Particles within hard drive assemblies can lead to friction and localized hot spots, which in turn can lead to failure of the hard drive and loss of the data magnetically encoded with it. One approach to this issue has been use of electroplated nickel as a particle suppression coating on the cover to the hard drive. However, nickel has tripled in price between about 2001 and about 2006. Also, the requirement to electroplate the hard drive cover leads to more steps in assembly than coating and curing of a low surface energy coating onto the hard drive assemblies, the electroplating process entails use of potentially hazardous materials, and particles shed from such coated parts are very hard, i.e., nickel particles, that can readily cause significant damage to the media and read/write head(s).
[0006] E-coats or electophoretically-deposited coatings are also used as particle suppression coatings but it can be difficult to obtain uniform coatings (necessitating some post coating machining). In addition, outgassing related to uncured monomers or absorption of hydrocarbons into the coatings that later outgas into the drive is encountered.
SUMMARY
[0007] The need exists for cheaper, more conveniently applied, high performance particle reduction coatings. Provided are improved coatings for particle suppression from substrates with oxide surfaces such as metals, e.g., aluminum, copper, stainless steel, etc., plastics, glass, ceramics, silicon, etc. The provided coatings can be applied with simple techniques (e.g., dip coating and thermal cure), exhibit thermal stability, can be formed in substantially uniform thin (e.g., from about 0.1 to about 5.0 microns) layers over complex substrate topographies. The coatings are clean (i.e., low outgassing, low extractable ions), are resistant to typical cleaning processes (e.g., aqueous and solvent-based cleaning solutions with or without ultrasonic treatment), are environmentally benign (i.e., delivered with solvents such as segregated hydrofluoroethers), have a good safety profile, and provide relatively superior cost-to-benefit performance as compared to the current industry method of nickel coating. The provided coatings may also provide corrosion protection.
[0008] The provided coatings comprise a thin polymer coating with reactive pendant groups having crosslinking functionality and superior ability to anchor to the substrate surface to suppress particle shedding from substrate surfaces. These particles can be from the substrate material or materials left over from processing and/or incomplete cleaning. This coating, in essence, forms a net over the surface of the substrate holding in particles, which otherwise could shed from the substrate.
[0009] In one aspect, provided is a substrate that includes a coating on at least a portion of said substrate wherein said coating comprises a fluorinated acrylate random copolymer having the following general formula:
[0000] XA w B x C y D z T
[0000] where X is the initiator residue or hydrogen, A represents units derived from one or more divalent fluorochemical acrylate monomers, B represents units derived from one or more divalent acrylate monomers with a functional group, C represents units derived from one or more non-fluorinated divalent acrylate monomers with a hydrocarbon group, D represents units derived from one or more curatives, T represents a functional terminal group or X defined as above, w is an integer from 1 up to about 200, x is an integer from 1 up to about 300, y is an integer from 1 up to about 100, and z is an integer from 0 up to about 30, and
wherein C is selected from the group consisting of monomers whose homopolymer has a glass transition temperature of less than or equal to 20° C.
[0010] In another aspect, provided is a method of reducing particulate contamination that includes providing at least one of a hard disk drive assembly, a MEMS device, a process equipment for electronics or a printed circuit card assembly, and applying a coating on at least a portion of the assembly of at least one of a hard disk drive assembly, a MEMS device, a process equipment for electronics or a printed circuit card assembly, wherein the coating comprises a fluorinated acrylate random copolymer having the following general formula:
[0000] XA a B b C c D d T e
[0000] where X is the initiator residue or hydrogen, A represents units derived from one or more divalent fluorochemical acrylate monomers, B represents units derived from one or more divalent acrylate monomers with a functional group, C represents units derived from one or more non-fluorinated divalent acrylate monomers with a hydrocarbon group, D represents units derived from one or more curatives, T represents a functional terminal group or X defined as above, a+b+c+d+e=1, 0.20≦a≦0.90, 0.05≦b≦0.25, 0.05≦c≦0.65, 0.0005≦d≦0.03, and 0.0025≦e≦0.20, wherein a, b, c, d, and e are weight percentages of A, B, C, D, and T, respectively, and wherein C is selected from the group consisting of monomers whose homopolymer has a glass transition temperature of less than or equal to 20° C.
[0011] In brief summary, the provided substrates, coatings, and methods comprise the reaction product of specified fluorochemical monomers and hydrocarbon monomers wherein the coating is at least partially cured in situ on the substrate. When at least partially cured in place, such coatings can provide surprisingly good performance as particle reduction coatings on substrates. Incorporation of hydrocarbon segments into the backbone of the copolymer has been surprisingly found to improve the particle suppression performance of the subject coatings and increase the resistance of resultant coatings to cleaning processes, particularly those processes used on electronics components such as ultrasonic cleaning processes. The provided coatings offer many advantages including but not limited to the ease of obtaining thin, uniform coating on complex surfaces, good safety and environmental properties, and resultant coatings that exhibit low surface energy. The provided coatings provides particle suppression coatings that are of relatively lower cost, provide improved resistance to cleaning, improved particle suppression performance. Improved handling and abrasion resistance has also been observed.
[0012] As used herein, “acrylate” can also be understood to mean “methacyrlate”; and “pendant” refers to end groups and side groups.
GLOSSARY
[0013] As used herein the following abbreviations have the indicated meanings:
A174 is 3-trimethoxysilane propyl methacrylate; AA is acrylic acid; BA is butyl acrylate; BuMA is butyl methacrylate; EHA is 2-ethyl hexyl acrylate; FBSEA is C 4 F 9 SO 2 N(CH 3 )CH 2 CH 2 OC(O)CH═CH 2 which can be made by the procedure of Examples 2A and 2B of PCT Application No. WO01/30873A (Savu et al.) which is incorporated herein by reference in its entirety; FBSEMA is C 4 F 9 SO 2 N(CH 3 )CH 2 CH 2 OC(O)C(CH3)═CH 2 which can be made by the procedure as Examples 2A and 2B of PCT Application No. WO01/30873A; HFE is hydrofluoroether; HFPOMA is hexafluoroproplyene oxide methacrylate which can be made by the procedure of Preparative Example 3 of U.S. Pat. No. 6,995,222 (Buckanin et al.) which is incorporated herein by reference in its entirety; IOA is iso-octyl acrylate; MMA is methylmethacrylate; MPTS is 3-mercaptopropyl trimethoxysilane; and PFPHMA is heptafluorobutyl methacrylate (i.e., CF 3 CF 2 CF 2 CH 2 OC(O)C(CH3)=CH 2 ) which can be made by the procedure described in PCT Application No. WO 02/16517 (Savu et al.) at page 15, lines 8-29, which is incorporated herein by reference in its entirety.
[0027] The above summary is not intended to describe each disclosed embodiment of every implementation of the present invention. The brief description of the drawing and the detailed description which follows more particularly exemplify illustrative embodiments.
DETAILED DESCRIPTION
[0028] In the following description, it is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense.
[0029] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range.
[0030] In one embodiment, coatings of the invention comprise fluorinated acrylate copolymer compounds of the following general formula:
[0000] XA w B x C y D z T
[0000] where X represents the residue of an initiator or hydrogen, A represents units derived from one or more divalent fluorochemical acrylate monomers, B represents units derived from one or more divalent acrylate monomers with a functional group, C represents units derived from one or more non-fluorinated divalent acrylate monomers with a hydrocarbon group (preferably BA), D represents units derived from one or more curatives, e.g., acidic acrylate (preferably acrylic acid), and T represents a functional terminal group or X as described above. The curative, D, may be present in the copolymer or may be provided as an external catalyst. The copolymer can be random, i.e., the order of the A, B, C and D segments is random though it will be understood that some local portions may exhibit a more block copolymer structure. The number average molecular weight of the copolymer is from about 500 to about 50,000, preferably from about 1000 to about 10,000.
[0031] The values w, x, y and z are as follows: w is an integer from 1 up to about 200, x is an integer from 1 up to about 300, y is an integer from 1 up to about 100, and z is an integer from 0 up to about 30 wherein the ratio of z:(x+1) is from 0 up to less than about 0.3. The ratio of the sum of (w+y):x is greater than about 1 and less than about 20, preferably greater than about 2 and less than about 8. The ratio of y:w is typically from 0 up to less than 7, preferably greater than about 0.2 and less than about 1.5. This ratio is also limited by solubility of the resultant copolymer. If the ratio is too high, the resultant copolymer will no longer be sufficiently soluble in HFE making such embodiments more difficult to use. Co-solvents can help extend this ratio. At relatively higher ratios, the resultant coating may subject to increased tendency to absorb and later emit, e.g., outgas, organic contaminants.
[0032] A can be derived from fluorinated acrylic monomers, preferably FBSEA, PFPHMA, and HFPOMA. Other suitable fluorinated monomers may be used instead or in addition to the preferred materials listed here if desired. In some embodiments, A is a unit derived from a monomer having the formula,
[0000] R f QOC(═O)C(R)═CH 2
[0000] where R f is a perfluoroalkyl or perfluoropolyether group having 1 to 30 carbon atoms, Q is a divalent linking group selected from the group consisting of —(CH 2 ) n —, —(CH 2 ) n — SO 2 N(R′)—, and —(CH 2 ) n N(R″)C(═O)—, where R′ is —C n H (2n+1) , n is an integer from 1 to 6, and R″ is hydrogen or CH 3 .
[0033] B can derived from a functionalized divalent acrylate monomer, e.g., silane-containing propyl acrylate or ethyl acrylate, epoxy acrylate, or a divalent urethane acrylate. A preferred example is A174. B can serve to provide crosslinking between polymers as well as bonding to the substrate.
[0034] The hydrocarbon segments, i.e., C in the formula above, impart improved softness to the resultant copolymer making the resultant particle suppression coating more resistant to thermal stresses and mechanical stresses. The C segment can be derived from monomers that are preferably those whose homopolymer has a low T g , i.e., less than or equal to about 20° C. Illustrative examples of monomers suitable for use as C segments suitable for use in the present invention include methyl acrylate (CH 2 ═CHCOOCH 3 , T g =9 to 15° C.), butyl acrylate (CH 2 ═CHCOOC 4 H 9 , T g =−54° C. as reported in 4th Edition Polymer Handbook, L. E. Nielsen, Mechanical Properties of Polymers, Reinhold, N.Y., 1962), isooctyl acrylate (T g =−45° C. as reported in 4th Edition Polymer Handbook, A. R. Monahan, J. Polym. Sci. A-1, 4, 2381 (1966), and ethyl hexyl acrylate (T g =−50° C. as reported in 4th Edition Polymer Handbook, A. R. Monahan, J. Polym. Sci. A- 1, 4, 2381 (1966), and butyl methacrylate (T g =20° C. as reported in Encyclopedia Polymer Science and Technology, Vol. 3, p. 251, John Wiley and Sons Publishers). The C segment preferably does not contain a reactive group. The C segment also preferably exhibits effective solubility in fluorocarbon solvents which are used in the preparation process of the random acrylic copolymer before cross-linking. Typically, HFEs are preferred for this purpose as their use offers a number of processing and environmental advantages as well as allows for thin uniform coatings even on complex surfaces. If desired, blends of fluorocarbons solvents with organic solvents (i.e. ethyl acetate, IPA, etc.) can be used to extend the range of C monomer segments that can be used.
[0035] To improve the curing performance, the polymer precursor composition may optionally include one or more curatives, i.e., D in the formula. Illustrative examples include acidic acrylates, e.g., acrylic acid, methacrylic acid, carboxy propyl acrylate, carboxylic acids, and sulfonic acids, e.g., 2-acrylamido-2-methylpropane sulfonic acid. The curative may be fluorinated or not as desired. Use of a curative is generally preferred; because it is incorporated into the reaction product, there is typically no outgassing.
[0036] When D is 0, the curing rate of the coating material may be enhanced as desired by addition of effective amounts of suitable catalyst depending upon the selection of reactive groups, parameters of the substrate, desired processing conditions, etc. For example, for coatings made using a perfluoropolyether silanes may be catalyzed using such agents as KRYTOX 157 FSL perfluoropolyalkylether carboxylic acid from DuPont.
[0037] T can be a functionalized terminal group, e.g., a silane. T can be derived from a chain transfer agent. A preferred agent is MPTS.
[0038] A free radical initiator is generally used to initiate the polymerization or oligomerization reaction. Commonly known free-radical initiators can be used and examples thereof include azo compounds, such as azobisisobutyronitrile (AIBN), azo-2-cyanovaleric acid and the like, hydroperoxides such as cumene, t-butyl and t-amyl hydroperoxide, dialkyl peroxides such as di-t-butyl and dicumylperoxide, peroxyesters such as t-butyl peroctoate, t-butylperbenzoate and di-t-butylperoxy phthalate, diacylperoxides such as benzoyl peroxide and lauroyl peroxide. Additionally, it is contemplated that compounds that generate free radicals or acidic and radical species upon exposure to actinic radiation can also be used to initiate the polymerization reaction. Examples of such species include IRGACURE 651 and DAROCUR 1173 available from Ciba.
[0039] Preferably, the substrate and coating are selected such that the coating can be anchored to the substrate surface via covalent bonding. The reactive pendant groups, i.e., silane groups, on the molecule can contribute to this desired bonding performance. In addition, while we do not wish to be bound by this theory, it is believed that the coating may provide superior corrosion protection as the silane groups react with bonds sites on the substrate that would otherwise be susceptible to corrosion reactions.
[0040] The coating thickness may be on the order of or substantially smaller than the size of the particles being held on the substrate, e.g., coating thickness in the range of from about 0.01 to about 1.0 micron as compared to an average particle size in the range of from about 0.1 to more than 5 microns. In the presence of water, alkoxy groups can react with the functional groups of the B and/or T unit to form a silanol group on the polymer. The silanol group can react with other silanol groups, thus crosslinking the polymer, and in the case of oxide surfaces (e.g., aluminum, copper, silicon, ceramic materials, etc.), covalently bonding the polymer to the surface.
[0041] An illustrative method of coating substrates in accordance with the invention is as follows:
[0042] a) mixing the precursor materials described above, i.e., initiator, acrylates, curative (if any), etc. in a suitable solvent, e.g., a hydrofluoroether and reacting the precursor materials to yield a coating composition containing the random copolymer;
[0043] b) applying the coating composition to desired portions of a substrate (any suitable coating technique can be used);
[0044] c) evaporating the solvent to leave the random copolymer on the substrate (an advantage of HFE solvents is that they will evaporate quickly);
[0045] d) elevating the temperature, e.g., to from about 100° C. to about 150° C., to cause the coating to cross link and build adhesion to the substrate.
[0046] In some applications it is preferred to use a two stage curing process. In this case, step d) is divided into two steps. In the first step, the coated substrate is cured so that the coating is tack-free, but has remaining reactive pendant groups. The coated substrate may then be run through additional processing. This may include addition of tapes, labels, epoxies or “form-in-place-gaskets”. In the second step, the coated substrate is completely cured. This two stage cure can improve the adhesion of tapes, labels, epoxies and “form-in-place-gaskets. The curing in each step is preferably done at elevated temperatures. It has also been observed that superior results are typically achieved if the coating is cured by heating at a relatively lower temperature for longer time than if cured by heating at a higher temperature for shorter time, e.g., at about 120° C. rather than about 150° C. Subsequent adhesion to articles with coatings of the invention can be improved by wiping with a fluorochemical solvent shortly before bonding.
[0047] In another embodiment, provided is a method of reducing particulate contamination that includes providing at least one of a hard disk drive assembly, a MEMS device, a process equipment for electronics or a printed circuit card assembly; and applying a coating on at least a portion of the assembly of at least one of a hard disk drive assembly, a MEMS device, a process equipment for electronics or a printed circuit card assembly, wherein the coating comprises a fluorinated acrylate random copolymer having the following general formula:
[0000] XA a B b C c D d T e
[0000] where X is the initiator residue or hydrogen, A represents units derived from one or more divalent fluorochemical acrylate monomers, B represents units derived from one or more divalent acrylate monomers with a functional group, C represents units derived from one or more non-fluorinated divalent acrylate monomers with a hydrocarbon group, D represents units derived from one or more curatives, T represents a functional terminal group or X defined as above, a+b+c+d+e=1; 0.20≦a≦0.90, 0.05≦b≦0.25, 0.05≦c≦0.65, 0.0005≦d≦0.03, and 0.0025≦e≦0.20, wherein a, b, c, d, and e are weight percentages of A, B, C, D, and T, respectively, and wherein C is selected from the group consisting of monomers whose homopolymer has a glass transition temperature of less than or equal to 20° C. In some preferred embodiments, 0.40≦a≦0.80 and 0.05≦c≦0.25.
[0048] The provided coatings can be of use in a variety of high purity applications such in hard disk drive assemblies including such components as spacers, disk clamps, e-blocks, cover plates, base plates, microactuators, sliders, voice coils, voice coil plates etc. These components are all potential sources of particles in finished disk drive systems. Coatings of the invention may also be used to reduce particle shedding for MEMS (Micro Electrical-Mechanical Systems), high purity processing (coating process equipment to reduce potential contamination), and semiconductor processing applications, e.g., surface mount components on a printed circuit card assembly. In addition, coatings of the invention have been observed to impart anti-smudge and easy clean performance to substrates to which they are applied.
[0049] Objects and advantages of this invention are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention.
EXAMPLES
[0050] Test Substrates: Aluminum (Al5052 H32) and stainless steel (SS304) sheets were purchased from M. Vincent & Associates of Minneapolis, Minn. and cut into test coupons approximately 51 mm×25 mm×1.6 mm in size for aluminum and 51 mm×25 mm×0.4 mm for stainless steel.
[0051] Cleaning Method 1: Prior to applying the coating, the substrates were cleaned by wipe cleaning using isopropyl alcohol (from EMD Chemicals of Gibbstown, N.J., part number PX1835P-4) and VWR SPEC-WIPE 7 Wipers (from VWR International, LLC of West Chester, Pa.).
[0052] Cleaning Method 2: Prior to coating, substrates were cleaned in two stages by vapor degreasing. In the first stage, a two sump vapor degreaser, model number 1012, obtained from Ultra-Kool, Inc. of Gilbertsville, Pa. was used to clean with 3M Novec HFE-72DA (from 3M Co. of St. Paul, Minn.) using the following parameters:
[0053] 30 seconds initial vapor rinse,
[0054] 300 seconds in the rinse sump with 40 kHz ultrasonics, and
[0055] 30 seconds final vapor rinse.
[0056] In the second stage, a two sump vapor degreaser, model number LAB-KLEEN 612 Degreasing System, from Unique Equipment Corporation of Montrose, Calif. was used to clean with an azeotrope of 89% (by weight) 3M NOVEC 7300 Engineered Fluid (from 3M Co. of St. Paul, Minn.) and 11% DOWANOL PM Propylene Glycol Methyl Ether (from Dow Chemical Company of Midland, Mich.) using the following parameters:
[0057] 30 seconds initial vapor rinse,
[0058] 300 seconds in the rinse sump with 40 kHz ultrasonics, and
[0059] 30 seconds final vapor rinse.
[0060] Coating Method: The coating was applied to the substrate by dip coating.
[0061] Determination of Percent Cure: A solvent extraction test method was used to determine if the coating crosslinked and adhered to the substrate. Prior to coating, the mass of the substrate was recorded (M BC ). The mass of the substrate after coating and curing was also recorded (M AC ). The substrate was then immersed in 3M™ NOVEC 7100 Engineering Fluid (methoxy-nonafluorobutane (C 4 F 9 OCH 3 ) from 3M Company of Saint Paul, Minn.) for 2 minutes. During this time the substrate was gently swirled in the solution. The mass of the substrate after solvent extraction was then recorded (M SE ). The extent of curing was then determined by the following calculation:
[0000] Percent Cure=[( M SE −M BC )/( M AC −M BC )]*100
[0000] This test was typically run on three substrate pieces for repeatability.
[0062] Particle Extraction Method: Liquid particle counter (LPC) extraction was used to determine the tendency of a substrate to shed particles. The test method used is based on IDEMA Microcontamination Standard M9-98.
[0063] All testing occurred in a clean hood with a class 100 environment. The water used throughout the testing was 18.2 MΩ (supplied using a NANOpure DIAMOND Analytical Ultrapure Water System from Barnstead International of Dubuque, Iowa, part number D11901) and filtered with an EMFLON II, 0.2 micron absolute filter (from Pall Corporation of East Hills, N.Y., part number DFA4001V002PV).
[0064] The test apparatus consisted of a 600 mL beaker (from VWR International, LLC of West Chester, Pa.) fixtured in an ultrasonic bath (from Crest Ultrasonics Corporation of Trenton, N.J., part number 6HT-1014-6T). The ultrasonics to the tank was supplied by a generator (from Crest Ultrasonics Corporation of Trenton, N.J., part number 6HT-1014-6W). The substrates to be tested were suspended in the beaker using a 28 gauge, solderable polyurethane stator wire (from MWS Wire Industries of Westlake Village, Calif., part number 28 SPN-155 RED) such that the neither the wire nor the substrate contact the beaker. The particle levels in the water were measured using an 8103 syringe sampling system (from Hach Ultra Analytics of Grants Pass, Oreg.).
[0065] For the testing, the beaker was filled with 500 mL of water. With the stator wire in the fluid, the beaker subjected to 30 seconds of 68 kHz ultrasonic treatment at 40 Watts per gallon. The particle levels in the fluid were measured by taking a 10 mL sample twice. The average of these results was used a blank. The substrate to be tested was then completely immersed in the water of the beaker and subjected to the same ultrasonic conditions described above. The particle levels in the fluid were then measured again using the same method as above. The particle counts generated per surface area of the substrate were calculated as follows:
[0000] Particle Counts=[(test sample particle count−blank particle count)*500 mL]/[substrate surface area]
[0066] The above procedure was repeated for three times for each substrate piece. The results presented below are for the third extraction.
Example 1
[0067] A copolymer was prepared by charging 25 g HFPOMA, 10 g BA (from Aldrich Chemical Company of Milwaukee, Wis.), 10 g A174 (from United Chemical Technologies of Bristol, N.J.), 5 g MPTS (from United Chemical Technologies, Inc.) and 250 g of 3M NOVEC 7200 Engineering Fluid (ethoxy-nonafluorobutane (C 4 F 9 OC 2 H 5 ) from 3M Company, St. Paul, Minn.) to a flask equipped with a mixer. The solution was purged with nitrogen for 5 minutes. Following this, 1 g of LUPEROX 26M50 initiator (tert-butyl peroxy-2-ethylhexanoate, 50% solids, from Arkema, Inc. of Philadelphia, Pa.) was charged to the flask. The solution was stirred under nitrogen and heated to 65° C. for 18 hours. This solution was diluted to 10% polymer with 3M NOVEC 7200 Engineering Fluid. The polymer solution was catalyzed by adding KRYTOX 157 FSL (perfluoropolyalkylether carboxylic acid from E.I. du Pont De Nemours & Company of Deepwater, N.J.) at 2% of the polymer level, i.e., about 0.2% of the overall solution.)
[0068] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 2.54 millimeters/second (6 inches/minute). A two step cure was used with the first cure done at 85° C. for one hour and the second cure done at 150° C. for 1 hour. Solvent extraction testing showed 95% cure for coatings on the aluminum coupon. The LPC extraction results on for these coatings are presented in Table 1.
Example 2
[0069] A copolymer was prepared by charging 30 g HFPOMA, 5 g BA, 10 g Al 74, 5 g MPTS and 250 g of 3M NOVEC 7200 Engineering Fluid to a flask equipped with a mixer. The solution was purged with nitrogen for 5 minutes. Following this, 1 g of LUPEROX 26M50 initiator was charged to the flask. The solution was stirred under nitrogen and heated to 65° C. for 18 hours. This solution was diluted to 10% polymer with 3M NOVEC 7200 Engineering Fluid. The polymer solution was catalyzed by adding KRYTOX 157 FSL at 2% of the polymer level, about 0.2% of the overall solution.
[0070] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 2.54 millimeters/second (6 inches/minute). A two step cure was used with the first cure done at 85° C. for one hour and the second cure done at 150° C. for 1 hour. Solvent extraction testing showed 86% cure for coatings. The LPC extraction results on for these coatings are presented in Table 1.
Comparative Example 1
[0071] A copolymer was prepared by charging 35 g HFPOMA, 10 g A174, 5 g MPTS and 250 g of 3M™ NOVEC 7200 Engineering Fluid to a flask equipped with a mixer. The solution was purged with nitrogen for 5 minutes. Following this, 1 g of LUPEROX 26M50 initiator was charged to the flask. The solution was stirred under nitrogen and heated to 65° C. for 18 hours. This solution was diluted to 10% polymer with 3M NOVEC 7200 Engineering Fluid. The polymer solution was catalyzed by adding KRYTOX 157 FSL at 2% of the polymer level, i.e., about 0.2% of the overall solution.
[0072] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 2.54 millimeters/second (6 inches/minute). A two step cure was used with the first cure done at 85° C. for one hour and the second cure done at 150° C. for 1 hour. Solvent extraction testing showed 100% cure for coatings. The LPC extraction results for these coatings are presented in Table 1.
[0000]
TABLE 1*
Substrate
Al 5052 H32
Particle Count**
% Particle Reduction
Control***
325,612
—
Example 1
12,206
96%
Example 2
8,864
97%
Comparative Example 1
22,498
93%
*Results are average of 5 samples
**Number of particles >0.3μ per cm 2 of substrate
***Control samples were aluminum coupons with no coating
[0073] Analysis of the data in Table 1 showed Example 1 and Example 2 to have a statistically significant improvement in particle suppression over Comparative Example 1.
Example 3
[0074] A copolymer was prepared by charging 15 g FBSEA, 26 g BA, 4.5 g A174, 1.5 g MPTS, 3.0 g CN973J75 (from Sartomer Company, Inc. of Exton, Pa.), 100 g 3M™ NOVEC 7200 Engineering Fluid, and 100 g ethyl acetate (product number EX0241 from EMD Chemicals, Inc. of Gibbstown, N.J.) to a flask equipped with a mixer. The solution was purged with nitrogen for 5 minutes. Following this, 0.5 g of VAZO 67 (from DuPont) was charged to flask. The solution was stirred under nitrogen and was heated to 65° C. for 16 hours. The solution was diluted to 10% polymer with a 50/50 blend by mass of 3M™ NOVEC 7200 Engineering Fluid and ethyl acetate. The polymer solution was catalyzed by adding KRYTOX 157 FSL at 3% of the polymer level, i.e., about 0.3% of the overall solution.
[0075] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 2. These coupons were then coated with the polymer solution using the method described above using a pull rate of 2.54 millimeters/second (6 inches/minute). A two step cure was used with the first cure done at 85° C. for one hour and the second cure done at 150° C. for 1 hour. Solvent extraction testing showed 79% cure on aluminum and 88% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 2.
Example 4
[0076] A copolymer was prepared by charging 12 g FBSEA, 26 g BA, 4.5 g A174, 1.5 g MPTS, 6.0 g CN973J75, 100 g 3M NOVEC 7200 Engineering Fluid, and 100 g ethyl acetate to a flask equipped with a mixer. The solution was purged with nitrogen for 5 minutes. Following this, 0.5 g of VAZO 67 was charged to flask. The solution was stirred under nitrogen and was heated to 65° C. for 16 hours. The solution was diluted to 10% polymer with a 50/50 blend by mass of 3M™ NOVEC 7200 Engineering Fluid and ethyl acetate. The polymer solution was catalyzed by adding KRYTOX 157 FSL at 3% of the polymer level, i.e., about 0.3% of the overall solution.
[0077] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 2. These coupons were then coated with the polymer solution using the method described above using a pull rate of 2.54 millimeters/second (6 inches/minute). A two step cure was used with the first cure done at 85° C. for one hour and the second cure done at 150° C. for 1 hour. Solvent extraction testing showed 78% cure on aluminum and 92% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 2.
[0000]
TABLE 2*
Substrate
Al5052 H32
SS304
Particle
% Particle
Particle
% Particle
Count**
Reduction
Count**
Reduction
Control***
240,610
—
150,520
—
Example 3
11,671
95%
1.826
99%
Example 4
13,297
94%
962
99%
*Results are from a single sample
**Number of particles >0.3μ per cm 2 of substrate
***Control samples were coupons with no coating
Example 5
[0078] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 18 g A174, 6 g MPTS, 2 g AA (from Alfa Aesar of Heysham, Lancashire LA3 2XY United Kingdom), 1 g 1-butyl peroctoate (LUPEROX 26, 100% active ingredient) (from Atofina of Philadelphia, Pa.), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0079] A15052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 97% cure on aluminum and 100% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
Example 6
[0080] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 20 g A174, 4 g MPTS, 2 g mercaptoproprionic acid (from Aldrich of Milwaukee, Wis.), 1 g t-butyl peroctoate (100%) and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0081] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 93% cure on aluminum and 95% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
Example 7
[0082] A copolymer was prepared by charging 54 g FBSEA, 20 g BA, 18 g A174, 6 g MPTS, 2 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M™ NOVEC 7200 Engineering Fluid.
[0083] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 95% cure on aluminum and 100% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
Example 8
[0084] A copolymer was prepared by charging 54 g FBSEMA, 20 g BA, 18 g A174, 6 g MPTS, 2 g AA, 1 g t-butyl peroctoate (LUPEROX 26), 450 g 3M NOVEC 7200 Engineering Fluid and 50 g of ethyl acetate to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0085] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 100% cure on aluminum and 100% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
Example 9
[0086] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 19 g A174, 6 g MPTS, 1 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0087] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 90% cure on aluminum and 92% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
Example 10
[0088] A copolymer was prepared by charging 54 g PFPHMA, 20 g EHA (from Aldrich), 18 g A174, 6 g MPTS, 2 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0089] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 100% cure on aluminum and 97% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
Example 11
[0090] A copolymer was prepared by charging 54 g PFPHMA, 20 g IOA (from Aldrich), 18 g A174, 6 g MPTS, 2 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0091] Al5052 H32 and SS304 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 98% cure on aluminum and 100% cure on stainless steel. The LPC extraction testing for this coating is presented in Table 3.
[0000]
TABLE 3*
Substrate
Al5052 H32
SS304
Particle
% Particle
Particle
% Particle
Count**
Reduction
Count**
Reduction
Control***
309,063
—
148,912
—
Example 5
43,986
86%
8,709
94%
Example 6
16,330
95%
4,922
97%
Example 7
26,184
92%
6,436
96%
Example 8
28,135
91%
2,775
98%
Example 9
17,801
94%
4,196
97%
Example 10
28,222
91%
3,472
98%
Example 11
10,621
97%
1,673
99%
*Results are from a single sample
**Number of particles >0.3μ per cm 2 of substrate
***Control samples were coupons with no coating
Comparative Example 2
[0092] A copolymer was prepared by charging 54 g PFPHMA, 20 g MMA (from Rohm and Haas of Philadelphia, Pa.), 19 g A174, 6 g MPTS, 1 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0093] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 98% cure. The LPC extraction testing for this coating is presented in Table 4.
Comparative Example 3
[0094] A copolymer was prepared by charging 54 g FBSEA, 20 g MMA, 19 g A174, 6 g MPTS, 1 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC™ 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0095] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 94% cure. The LPC extraction testing for this coating is presented in Table 4.
Example 12
[0096] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 19 g A174, 6 g MPTS, 1 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0097] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour.
[0000] Solvent extraction testing showed 86% cure. The LPC extraction testing for this coating is presented in Table 4.
Example 13
[0098] A copolymer was prepared by charging 54 g FBSEA, 20 gBuMA (from Lucite International of Southampton SO14 3BP, United Kingdom ), 19 g A174, 6 g MPTS, 1 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M™ NOVEC 7200 Engineering Fluid.
[0099] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour.
[0000] Solvent extraction testing showed 89% cure. The LPC extraction testing for this coating is presented in Table 4.
Example 14
[0100] A copolymer was prepared by charging 54 g PFPHMA, 20 g BuMA, 19 g A174, 6 g MPTS, 1 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M™ NOVEC 7200 Engineering Fluid.
[0101] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 120° C. for 1 hour. Solvent extraction testing showed 89% cure. The LPC extraction testing for this coating is presented in Table 4.
[0000]
TABLE 4*
Substrate
Al 5052 H32
Particle Count**
% Particle Reduction
Control***
287,684
—
Example 12
17,567
94%
Comparative Example 2
57,866
80%
Comparative Example 3
83,810
71%
Example 13
41,712
86%
Example 14
21,729
92%
*Results are average of 3 samples, with the exception of Example 12 which is the average of 2 samples.
**Number of particles >0.3μ per cm 2 of substrate
***Control samples were aluminum coupons with no coating
Comparative Example 4
[0102] A copolymer was prepared by charging 54 g PFPHMA, 20 g BuMA, 19 g A174, 6 g MPTS, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M™ NOVEC 7200 Engineering Fluid.
[0103] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The coated coupons were heated at 120° C. for 1 hour. Solvent extraction testing showed 0% cure.
Example 15
[0104] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 19.5 g A174, 6 g MPTS, 0.5 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M NOVEC 7200 Engineering Fluid.
[0105] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). Three types of cures were run. The solvent extraction data is presented in Table 5.
Example 16
[0106] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 19.7 g A174, 6 g MPTS, 0.3 g AA, 1 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was diluted to 10% polymer by mass with 3M™ NOVEC 7200 Engineering Fluid.
[0107] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). Three types of cures were run. The solvent extraction data is presented in Table 5.
[0000]
TABLE 5*
Substrate
Al 5052 H32
Cure Conditions
Percent Cure
Example 15
120° C., 1 hour
73%
120° C., 3 hours
81%
150° C., 1 hour
100%
Example 16
120° C., 1 hour
41%
120° C., 3 hours
71%
150° C., 1 hour
92%
*Results are average of 3 samples
Example 17
[0108] A copolymer was prepared by charging 54 g PFPHMA, 20 g BA, 19.5 g A174, 6 g MPTS, 0.5 g AA, 0.22 g of polymerizable dye AD-4 (U.S. Pat. No. 6,894,105 (Parent et al.), Column 9 and 22 line 44), 2 g t-butyl peroctoate (LUPEROX 26), and 500 g 3M NOVEC 7200 Engineering Fluid to a flask under positive nitrogen pressure. The solution was stirred under nitrogen and was heated to 70° C. for 18 hours. The solution was filtered through a 0.1 micron nylon filter and was diluted to 10% polymer by mass with 3M™ NOVEC 7200 Engineering Fluid.
[0109] Al5052 H32 test coupons were cleaned by Cleaning Method 1. These coupons were then coated with the polymer solution using the method described above with using a pull rate of 4.66 millimeters/second (11 inches/minute). The cure was done at 150° C. for 1 hour.
[0110] Solvent extraction testing showed 92% cure. The LPC extraction testing for this coating is presented in Table 6.
[0000]
TABLE 6*
Substrate
Al 5052 H32
Particle Count**
% Particle Reduction
Control***
386,800
—
Example 12
4,900
99%
*Results are average of 3 samples
**Number of particles >0.3μ per cm 2 of substrate
***Control samples were aluminum coupons with no coating
[0111] Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein as follows. | The present disclosure relates to high purity apparati, e.g., magnetic hard disk drives, and more specifically, to coatings for particle reduction of surfaces of such apparati. The provided coatings include thin polymer coatings with reactive pendant groups having crosslinking functionality and ability to anchor to substrate surfaces to suppress particle shedding from substrate surfaces. Provided is a substrate that includes a coating on at least a portion of the substrate that comprises a fluorinated acrylate random copolymer. Methods of reducing particulate contamination are also provided. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/915,817 entitled “Preparation of Group IV Semiconductor Nanoparticle Materials and Dispersions Thereof,” filed May 3, 2007, which is incorporated by reference.
FIELD OF DISCLOSURE
[0002] This disclosure relates to the preparation of Group IV semiconductor nanoparticles and preparation of stable dispersions of Group IV semiconductor nanoparticles.
BACKGROUND
[0003] The Group IV semiconductor materials enjoy wide acceptance as the materials of choice in a range of devices in numerous markets such as communications, computation, and energy. Currently, there is interest in using Group IV semiconductor nanoparticle materials in a wide range of components and devices.
[0004] For example, due to the luminescent properties of small nanoparticles, silicon and germanium nanoparticles have been contemplated for use in light-emitting applications, including use as phosphors for solid-state lighting, luminescent taggants for biological applications, security markers and related anti-counterfeiting measures. Other potential applications of Group IV semiconductor nanoparticles include a variety of optoelectronic devices, such as light-emitting diodes, photodiodes, photovoltaic cells, and sensors that utilize their unique optical and semiconductor properties. Because of the ability to produce colloidal forms of semiconductor nanoparticles, these materials offer the potential of low-cost processing, such as printing, for producing a variety of electronic devices that is not possible with conventional semiconductor materials. In that regard, tantamount to dispensing Group IV nanoparticle materials is not only the formulation of stable dispersions of the materials, which dispersions enable printing in a number of formats, but in formulations of inks which are suitable for the fabrication of a variety of optoelectric devices, such as photovoltaic devices.
[0005] In WO04068536A2 [Harting, et al.; International Patent Application No. WO2004IB00221, filing date Jan. 30, 2003] formulations of nanocrystalline silicon particles of about 30 nm in diameter, and formulated in a solvent-binder carriers are described. The nanoparticles were mixed with organic binders such as polystyrene in solvents such as chloroform to produce semiconductor inks that were printed on bond paper without further processing. In U.S. Patent Application Publication No. 2006/0154036 [Kunze, et al.; Ser. No. 11/373,696; filing date Mar. 10, 2006], composite sintered thin films of Group IV nanoparticles and hydrogenated amorphous Group IV materials are described. The Group IV nanoparticles are in the range 0.1 to 10 nm, in which the nanoparticles were passivated, typically using an organic passivation layer.
[0006] Additionally, a component in the ink formulation; a second cyclic Group IV compound, is a compound including organic ligands that are alkyl, aryl, or aralkyl ligands. In order to fabricate thin films from these organic passivated particles and carbon-containing cyclic compounds, the processing was performed at above 400° C. In both examples, significant amounts of organic materials are present in the inks used to fabricate Group IV thin film layers. Such organic-laden dispersions are known to be problematic in producing the well-accepted native Group IV semiconductor thin films known in the semiconductor industry.
[0007] U.S. Pat. No. 7,062,848 [Pan, et al.; Ser. No. 10/665,335; filing date Sep. 18, 2003] discloses a printable composition of nanoparticles composed of a liquid carrier, anisometric nanostructures, and in some embodiments, a stabilizing agent that reacts with the nanoparticles to produce a surface-attached ligand. The ligands are recited as being drawn from broad chemical classes, such as carboxylates, thiolates, alkoxides, alkanes, alkenes, alkynes, diketonates, siloxanes, silanes, germanes, hyroxides, hydrides, amides, amines, carbonyls, nitriles, aryl, and combinations thereof. Likewise, examples of the liquid carrier was drawn from broad chemical classes including hydrocarbons, alcohols, ethers, organic acids, esters, aromatics, amines, as well as water, and mixtures thereof. Though anisomeric silicon and germanium nanoparticles are recited as subject nanoparticles, there is no disclosure for how to prepare stable dispersions of such Group IV semiconductor nanoparticles, which dispersions are suitable for making a variety of optoelectric devices, such as photovoltaic devices. Moreover, two examples are given for preparation of printable compositions of zinc oxide; one of which is passivated using carboxylate compounds, and the other preparation of zinc oxide where the ligand is only described as hydrophilic for the purpose of being prepared as an aqueous dispersion.
[0008] In U.S. Patent Application Publication No. 2006/0237719 [Colfer, et al.; Ser. No. 10/533,291; filing date Oct. 30, 2003] though note is made of the problem of oxidation of Group IV semiconductor nanoparticles, nonetheless description is given for the preparation of Group IV semiconductor nanoparticles in aqueous dispersions containing about 30% of the surfactant polyethylene glycol (MW 200). In some embodiments, a capping ligand, such as octanol or a carboxylate terminal alkyl group is noted to assist in the dispersion of Group IV semiconductor nanoparticles in non-aqueous or aqueous solvents, though the preparation of dispersions of such capped Group IV semiconductor nanoparticles is not disclosed. Further, examples of the fabrication of a variety of optoelectric devices, such as photovoltaic devices, using such dispersions is not given.
[0009] Accordingly, there is a need in the art for the preparation of Group IV nanoparticle materials, and dispersions of such Group IV semiconductor nanoparticles materials that are suited for the fabrication of a variety of optoelectric devices, such as photovoltaic devices. Such dispersions are not only amenable to printing using a variety of techniques for a range of print dimensions ranging from sub-micron to meters, but enable the ready fabrication of semiconductor devices.
SUMMARY
[0010] The invention relates, in one embodiment, to a method of forming an ink, the ink configured to form a densified film. The method includes providing a set of Group IV semiconductor particles, wherein each Group IV semiconductor particle of the set of Group IV semiconductor particles includes a particle surface with a first exposed particle surface volume. The method also includes reacting the set of Group IV semiconductor particles to a set of bulky capping agent molecules resulting in a second exposed particle surface volume, wherein the second exposed particle surface volume is less than the first exposed particle surface volume. The method further includes dispersing the set of Group IV semiconductor particles in a vehicle; and heating the vehicle, wherein the densified film is formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a flow chart depicting the process for making and printing embodiments of Group IV nanoparticle inks, in accordance with the invention;
[0012] FIG. 2A-B are Fourier Transform Infrared (FTIR) spectra of two embodiments of Group IV nanoparticle inks in comparison with a composition of Group IV nanoparticles prepared in a mixture of chloroform and chlorobenzene, in accordance with the invention;
[0013] FIG. 3A-B depict the light scattering size distribution determinations of two embodiments of Group IV nanoparticle inks in comparison with a composition of Group IV nanoparticles prepared in a mixture of chloroform and chlorobenzene, in accordance with the invention; and
[0014] FIG. 4A-B depict the Fourier Transform Infrared (FTIR) spectra of an embodiment of a Group IV nanoparticle ink ( FIG. 4A ), and the light scattering size distribution determination of the embodiment ( FIG. 4B ).
DETAILED DESCRIPTION
[0015] Embodiments of Group IV semiconductor nanoparticle inks formulated from Group IV semiconductor nanoparticles are disclosed herein. Various types of Group IV semiconductor nanoparticles may be utilized in the formulation of Group IV semiconductor inks. Examples include single or mixed elemental composition (including alloys, core/shell structures, doped nanoparticles, and combinations thereof), single or mixed shapes and sizes (and combinations thereof), and single form of crystallinity or a range or mixture of crystallinity (and combinations thereof). Such inks may be used in the fabrication of a range of optoelectric devices, on a variety of substrates using deposition methods such as, for example, but not limited by, roll coating, slot die coating, gravure printing, flexographic drum printing, and ink jet printing methods, or combinations thereof.
[0016] As previously mentioned, it is desirable to leverage the knowledge of Group IV semiconductor materials and at the same time exploit the advantages of Group IV semiconductor nanoparticles for producing novel thin film devices. The Group IV semiconductor nanoparticles, and the inks produced from them, must have properties that are suitable for producing high-quality Group IV semiconductor devices. Additionally, given the reactivity of the Group IV semiconductor nanoparticles, care must be taken from the point of synthesis of the Group IV semiconductor nanoparticles to avoid contamination known to be undesirable in semiconductor devices.
[0017] FIG. 1 is a flow chart is shown for the preparation of Group IV semiconductor nanoparticle materials and inks, for the purpose of printing. In the first step 10 , the preparation of Group IV semiconductor nanoparticles in an inert environment is indicated. Though any method of producing Group IV semiconductor nanoparticle materials in an inert environment may be used, gas phase methods for the preparation of Group IV semiconductor nanoparticles are exemplary of methods for producing high quality Group IV semiconductor nanoparticle materials in an inert environment. For example, U.S. patent application Ser. No. 11/155,340 (filing date Jun. 17, 2005), describes the preparation of Group IV semiconductor nanoparticles using an RF plasma apparatus, while U.S. Patent Application No. 60/878,328 (filing date Dec. 21, 2006) and U.S. Patent Application No. 60/901,768 (filing date Feb. 16, 2007) describe the gas phase preparation of doped Group IV semiconductor nanoparticle materials using an RF plasma apparatus. Additionally, U.S. Patent Application No. 60/920,471 (filing date Mar. 27, 2007) describes the use of a laser pyrolysis reactor for preparation of a variety of Group IV semiconductor nanoparticle materials. All of the aforementioned patent applications are incorporated by reference.
[0018] After the preparation of targeted Group IV semiconductor nanoparticle materials in step 10 of FIG. 1 , the preparation of Group IV nanoparticle materials with a capping agent 20 , followed by the formulation of the Group IV nanoparticle material with capping agent into inks in an inert environment in step 30 may be done. It is contemplated that desirable attributes for ink formulations for use in fabrication of a variety of optoelectric devices, such as photovoltaic devices, include, but are not limited by, prepared from Group IV nanoparticles of semiconductor grade, prepared in dispersions using materials that preserve the quality of the Group IV semiconductor nanoparticle starting materials, formulations that are readily adopted to a variety of printing technologies, and formulations of inks which show batch to-batch consistency. With respect to the preparation of inks that preserve the quality of the Group IV semiconductor nanoparticle materials, it is desirable to avoid any processing that introduces contaminants, such as, but not limited by, metals, oxygen, and carbon, since it is known that such materials may be difficult to process out readily, and are known to introduce trap states into semiconductor devices.
[0019] For example, it is known that for bulk semiconductor materials, substantially free of oxygen falls in the range of about 10 17 to 10 19 oxygen atoms per cubic centimeter of Group IV semiconductor material. In comparison, for example, for semiconductor grade silicon, there are 5.0×10 22 silicon atoms per cubic centimeter, while for semiconductor grade germanium there are 4.4×10 22 germanium atoms per cubic centimeter. In that regard, oxygen can be no greater than about 2 parts per million to about 200 parts per million as a contaminant in Group IV semiconductor materials. Therefore, one example of a metric of “inert” is having Group IV semiconductor nanoparticle inks disclosed herein be formulated in an environment that provides a suitably low exposure of the nanoparticle starting materials and ink formulations to sources of oxygen, such as but not limited by oxygen; whether gas or dissolved in a liquid, and water; whether vapor or liquid, so that they can be further processed to produce devices that have comparable electrical and photoconductive properties in comparison to devices fabricated from traditional bulk Group IV semiconductor materials.
[0020] One aspect of insuring that embodiments of Group IV semiconductor inks are suitable for use in the fabrication of a variety of optoelectric devices is to prepare the Group IV semiconductor nanoparticle materials, the capped materials, and the ink formulations in inert environments, as shown in steps 10 - 30 and of FIG. 1 . Though as previously discussed a substantially oxygen free environment is indicated in the fabrication and handling of the Group IV semiconductor nanoparticles, as used herein, “inert” is not limited to only substantially oxygen-free. It is recognized that other fluids (i.e. gases, solvents, and solutions) may react in such a way that they negatively affect the electrical and photoelectrical properties of Group IV semiconductor nanoparticles. Accordingly, an inert environment for the purposes of this disclosure is an environment in which there are no fluids (gases, solvents, and solutions) that react in such a way that they would negatively affect the electrical and photoelectrical properties of the Group IV semiconductor nanoparticles.
[0021] With respect to step 20 of FIG. 1 , the objective of the preparation of formulations of Group IV semiconductor with capping agents is to minimize the incorporation of high levels of undesirable materials, as mentioned in the above, while preparing stable dispersions that can be used to produce semiconductor thin film devices. It is known by those of skill in the art that classes of organic compounds, such as alcohols, aldehydes, ketones, carboxylic acids, esters, and amines as well as organosiloxanes, may react with surface groups of Group IV semiconductor nanoparticle materials to form capping groups. However, the judicious selection of certain species within these broad classes, as well as the method of preparation of the inks formulations is clearly differentiating in formulating Group IV semiconductor nanoparticle inks that are useful in the fabrication of a variety of optoelectric devices, such as photovoltaic devices, as will be discussed in more detail subsequently.
[0022] In that regard, for the selection of species suitable for capping agents, for some embodiments of inks formulated using Group IV semiconductor nanoparticle materials. it is contemplated that capping agents having bulky substituents are suited to fabrication of semiconductor devices. Although not limited by theoretical explanation, capping agents with bulky substituents provide a greater surface excluded volume once reacted with a surface Group IV semiconductor atom, and thereby limit the loading of the surface with capping groups. The synthetic strategy of such an approach is to limit surface loading. This may also be done using other strategies including the in situ capping of Group IV semiconductor nanoparticle materials, as will be discussed in more detail subsequently.
[0023] Another aspect of the selection of species suitable for capping agents is to provide adequate dispersion of the Group IV nanoparticle materials for printing. Still another aspect of the selection of suitable species for capping agents relates to the ease by which they may be removed in the process of fabrication of a semiconductor device. For example, bulky capping agents suitable for use in the preparation of capped Group IV semiconductor nanoparticles include C4-C8 branched alcohols, aldehydes, and ketones, such as tertiary-butanol, isobutanol, butanol, isobutanol, and oraganosiloxanes, such as methoxy(tris(trimethylsilyl)silane) (MTTMSS), tris(trimethylsilyl)silane (TTMSS), decamethyltetrasiloxane (DMTS), and trimethylmethoxysilane (TMOS).
[0024] In terms of the selection of a vehicle, a suitable solvent or vehicle for use in printing Group IV semiconductor nanoparticles and fabricating them into a range of optoelectric devices is a solvent or vehicle that effectively disperses the capped Group IV nanoparticles, given properties such as viscosity, density, and polarity, and is also effectively removed in the fabrication of semiconductor devices. For example, as previously mentioned, vehicles may be selected from the same broad classes as the capping agents. In addition to the classes of chemicals previously described for capping agents and specific examples from those classes, such as alcohols, aldehydes, ketones, carboxylic acids, esters, amines, and organosiloxanes, hydrocarbon solvents may be good vehicles for dispersion of Group IV semiconductor nanoparticle ink formulations. For example, chloroform, chlorobenzene, and mesitylene are examples of hydrocarbon solvents which may be used as vehicles in the preparation of Group IV semiconductor inks. Additionally, vehicle blends of one or more solvents from the above named vehicles are desirable to achieve vehicle attributes such as Viscosity, density, and polarity, and the like.
[0025] In some embodiments, the reaction of the capping agent is done to ensure that only one species will react with the highly reactive surface groups on a Group IV semiconductor nanoparticle material before the capped material is dispersed in a vehicle. For example, as will be discussed in more detail subsequently, the reaction of bulky capping agents, such as t-butanol, is done in a separate step from the suspension of the capped particles in a vehicle, such as diethylene glycol diethyl ether (DEGDE), to insure that only the bulky t-butanol groups will cap the Group IV nanoparticle materials. In other embodiments, the capping agent and the vehicle may be the same chemical species. For example, isobutanol and DEGDE may both react with the surface as a capping agent, as well as disperse the capped Group IV semiconductor nanoparticle materials in an ink formulation. In still other embodiments, the capping agent and the vehicle may be selected from different chemical families. For example, when TMOS is the capping agent, chloroform is a suitable vehicle.
[0026] In FIG. 2A and FIG. 2B the Fourier Transform Infrared (FTIR) spectra of two preparations of Group IV nanoparticle inks, both in comparison with a preparation of a composition of Group IV nanoparticle in a low-boiling organic solvent mixture. In FIG. 2A , the FTIR spectrum shown in the top, solid line is for a silicon nanoparticle ink formulation, prepared using t-butanol (C 4 H 10 O), so that the silicon nanoparticles have a t-butoxy capping group, with the diethylene glycol diethyl either DEGDE (C 8 H 18 O 3 ) used as the vehicle to disperse the t-butoxy capped silicon nanoparticles. The lower hatched spectrum in FIG. 2A is a preparation of silicon nanoparticles in a solvent mixture of chloroform:chlorobenzene (3:1), used as a control. In FIG. 2B , the FTIR spectrum shown in the top solid line is an ink formulation of silicon nanoparticles with no t-butoxy capping agent, but suspended in DEGDE, which acts as both a capping reagent and a vehicle. The lower hatched spectrum in FIG. 2B is the control as described for FIG. 2A .
[0027] The t-butoxy-capped silicon nanoparticles of FIG. 2A were prepared using silicon nanoparticles of about 6.6 nm in diameter. The selection of t-butanol met the attributes of capping agents as outlined above. Typically, a formulation of silicon nanoparticles in t-butanol and DEGDE was prepared with a weight percentage ratio of 2 weight % silicon nanoparticles, 49 weight % t-butanol, and 49 weight % DEGDE. To prepare this formulation, the t-butanol and silicon nanoparticles were prepared by first mixing the constituents in a typical weight ratio of 5 weight % silicon nanoparticles to 95 weight % t-butanol, and then reacting the t-butanol with the silicon nanoparticles using either ultrasonication for about 15 minutes or heating at about 100° C. with stirring for about 30 minutes. For formulation of the capped Group IV semiconductor nanoparticles as a printable ink, this reacted mixture was subsequently dispersed in DEGDE in a volumetric ratio of between about 1:1 to about 1:3 of reacted mixture: DEGDE, and sonicated for about 15 minutes. The silicon nanoparticles of FIG. 2B were prepared using silicon nanoparticles of about 8.0 nm in diameter. The ink formulation was prepared by suspending the silicon nanoparticles in DEGDE in a weight percentage ratio of 2 weight % silicon nanoparticles to 98 weight % DEGDE, and mixed using ultrasonication for about 15 minutes. As previously mentioned, since the silicon atoms at the surface of the nanoparticles will react with ethers, the DEGDE is both a capping agent as well as a vehicle, and forms an ethoxyethyl ether bound capping group on the surface of the nanoparticles. All procedures carried out as described from the synthesis of the particles through the preparation of the inks in the above were done in an inert dry, oxygen-free environment, using solvents of the highest specifications.
[0028] The FTIR spectra in FIG. 2A shown using a solid line are the spectra of the 6.6 nm silicon nanoparticles prepared with a t-butoxy capping group in DEGDE as described above. These are compared in the hatched spectrum to the same batch of nanoparticles prepared as a 20 mg/ml solution in chloroform:chlorobenzene (4:1). For the silicon nanoparticles prepared using the t-butanol capping reagent, the peak at about 2990 cm-1 with shoulder at about 2910 cm-1 is indicative of alkyl carbonhydrogen stretch, and is a signature of the methyl groups. The broad doublet peak which appears between about 950 cm-1 to about 1150 cm-1 is the signature for an Si—O—C moiety, and confirms that the t-butoxy group is surface bound to the silicon nanoparticles. In comparison to the silicon nanoparticles prepared as a composition in the chloroform:chlorobenzene (341) solution, these features are clearly absent.
[0029] The FTIR spectra in FIG. 2B shown using a solid line is the spectra of the 8.0 nm silicon nanoparticles prepared with DEGDE acting as both the capping reagent, well as the vehicle as described above, which are compared in the hatched spectrum to the same batch of nanoparticles prepared as a 20 mg/ml solution in chloroform:chlorobenzene (3:1). For the silicon nanoparticles prepared using a linear chain ether as a capping agent, the prominent doublet between about 2880 cm −1 to about 3000 cm −1 is indicative of ethyl carbon-hydrogen stretch. The broad peak which appears between about 1000 cm −1 to about 1200 cm −1 is the signature for a Si—O—C mode, and confirms that an ethoxyethyl ether group is surface bound to the silicon nanoparticles. In comparison to the silicon nanoparticles prepared as a composition in the chloroform:chlorobenzene (3:1) solution, these features are clearly absent.
[0030] FIG. 3A and FIG. 3B show the results of the particle size distribution analysis using light scattering of the two formulations of inks versus the control. In FIG. 3A , the solid line representing a trimodal distribution of particle distribution for the t-butoxy capped silicon nanoparticles, shows a population silicon nanoparticle agglomerates at about 3.9 microns, another a population silicon nanoparticle agglomerates at about 850 nm, and a broadly dispersed population at about 150 nm. For the ethoxyethyl ether capped silicon nanoparticles represented by the solid line in FIG. 3B , a bimodal distribution is indicated, showing a major of silicon nanoparticle agglomerates at about 800 nm, and a minor peak at about of silicon nanoparticle agglomerates 125 nm. In both instances, the dispersions were stable, and proved suitable for ink jet printing. As one of skill in the art of printing is apprised, ink jet printing is a good bench mark for a printable formulation, since such formulations may be easily adjusted to a range of formats of other printing technologies. Additionally, ink jet printing allows a range of scale of printing from sub-micron to meters. The hatched line shown in both FIG. 3A and FIG. 3B represents the control composition of silicon nanoparticles in chloroform:chlorobenzene (3:1), which shows a broad distribution of silicon nanoparticle agglomerates at about 1.5 micron. It should be noted that the silicon nanoparticles are not a stable dispersion in the chloroform:chlorobenzene solution, and settle out within a day. This is in contrast to the stable ink formulations of the t-butoxy capped silicon nanoparticles in DEGDE, and the ethoxyethyl ether capped silicon nanoparticles in DEGDE.
[0031] Although both inks show that the nanoparticles are in populations of agglomerates, it should be noted that, as indicated in FIG. 1 , step 10 the Group IV semiconductor nanoparticles are produced as high quality material, without signs of soft or hard agglomeration. This was demonstrated in a first transmission electron micrograph (TEM) of silicon nanoparticles of high quality made in an inert environment, as per step 10 of FIG. 1 . In this TEM image, the particles appear to have an average diameter of about 10.0 nm, clearly have the morphology of distinct particles, and appear to be fairly monodispersed.
[0032] In contrast, in second TEM image of a commercially available preparation of silicon nanoparticles, considerable fusion is between particles evident, in which networks of amorphous material bridge nanoparticle material. Upon careful inspection, it can also be seen that very small particles are fused with fairly large particles, so that polydispersity is also evident in this sample. Embodiments of ink formulations disclosed herein are prepared with materials, such as the silicon nanoparticles, so that the populations of agglomerates in the ink formulations as shown in FIG. 3A and FIG. 3B are not formed from nanoparticle materials suffering from hard agglomerates.
EXAMPLE
[0033] A first thin film was produced using an ink formulation as previously described, in which silicon nanoparticles are capped with t-butoxy groups dispersed in DEGDE, while a second thin film was produced using an ink formulation as previously described, in which silicon nanoparticles are capped ethoxyethyl ether groups dispersed in DEGDE.
[0034] For the preparation of the first and second thin films, the substrate used was a 1″×1″×0.2″ silicon (100) substrate, which was doped with boron with a resistivity of about 10˜20 ohm-cm. Two layers of silicon nanoparticles were printed on the substrate with the respective inks, as described above. The deposited silicon nanoparticle thin films were processed in vacuo in a fabrication chamber having a top and bottom heating element, which were controlled to the same target temperatures. In a first preconditioning step, the samples were subjected to 350° C. using a 15-minute ramp to the target temperature, followed by a 10-minute hold. During the following fabrication step, the samples were ramped to 805° C., and held at that temperature for 6 minutes.
[0035] In a first set of SEM (scanning electron microscopy) images, it was observed that the t-butoxy/DEGDE capping group/vehicle formulation produces a densified film having large grains. In contrast, the ethoxyethyl ether/DEGDE formulation produces a densified film in which the grain growth is clearly limited. The butoxy/DEGDE capping group/vehicle formulation is believed to be effective in the fabrication of a Group IV semiconductor thin film due to the limitation of the surface loading of the bulky group, as well as the substantial removal of these groups in the preprocessing step, before thin film fabrication, leaving only a small residual to be removed during the fabrication step. Clearly, while both the t-butoxy/DEGDE capping group/vehicle formulation and the ethoxyethyl ether/DEGDE formulation are printable compositions of Group IV semiconductor inks, both do not produce a densified Group IV semiconductor thin film under comparable fabrication conditions.
[0036] In that regard, these results show the impact of matching the attributes of a printable composition of a Group IV semiconductor ink to the choice of capping agent and vehicle, and how the method of formulation of the ink impacts the fabrication of a Group IV semiconductor thin film. Clearly, in addition to the preparation of quality Group IV nanoparticle materials in an inert environment as per 10 of FIG. 1 , the method of making the surface-capped Group IV nanoparticle materials in an inert environment, with proper selection and preparation of the capping reagent as per 20 of FIG. 1 , along with formulation of an ink in an inert environment using the proper selection of the vehicle as per 30 of FIG. 1 is differentiating. Such steps in the formulation of a Group IV nanoparticle ink are indicated in light of the extraordinary reactivity of the Group IV nanoparticle surface groups to a variety of chemical species.
[0037] FIG. 4A-B are FTIR spectra ( FIG. 4A ), as well as the particle size distribution analysis using light scattering ( FIG. 4B ) for another example of an embodiment of a Group IV semiconductor ink that produce densified Group IV semiconductor thin films. The Group IV semiconductor nanoparticles are silicon nanoparticles of about 6 nm in diameter, and the capping reagent in this example is selected from organosilioxanes of the general formula:
[0000] R n Si(OR′) 4-n where n=1-3; and R, R′ are selected from alkyl, aryl, and aralkyl
[0039] In this example, the organosiloxane capping agent is methoxy(tris(trimethylsilyl)silane), or MTTMSS, and the vehicle is (tris(trimethylsilyl)silane), or TTMSS, The MTTMSS, like the t-butanol capping reagent, has bulky substituents. As seen in the FTIR spectra of nanoparticles prepared using the MTTMSS capping agent in FIG. 6A (solid line), the signature of the methyl groups at between about 2800 cm-1 to about 3000 cm-1 on the surface of the silicon nanoparticles is evident. The broad peak centered at about 1070 cm-1 indicates the presence of an Si—O—Si group. These features are absent in the control spectrum represented by the hatched line, which represents silicon nanoparticles prepared as a composition in the chloroform:chlorobenzene (4:1) solution. In FIG. 4B , particle size distribution data indicate a dominant peak at about 600 nm.
[0040] Further, the densified thin film 120 was fabricated from printed thin films deposited on the substrate using an embodiment of the MTTMSS capping agent/TTMSS vehicle Group IV semiconductor ink. In the preparation of the thin film shown in FIG. 4A-B , the substrate 110 used was a 1″×1″×0.2″ silicon (100) substrate, which was doped with boron with a resistivity of about 10 ohm·cm. Two layers of silicon nanoparticles were printed on the substrate with the ink, as described above. The deposited silicon nanoparticle thin films were processed in vacuo in a fabrication chamber having a top and bottom heating element, which were controlled to the same target temperatures. During the fabrication step after the application of the first layer of silicon nanoparticles, the samples were ramped to 805° C. over 14 minutes, and held at that temperature for 6 minutes. The samples were then mechanically and chemically cleaned, a second layer of silicon nanoparticles was printed, and the same fabrication steps as described for the fabrication of the first thin film layer were applied. It was observed that the fabricated silicon thin film 120 was densified to a degree that it is indistinguishable in appearance from the silicon substrate 110 .
[0041] Finally, as one of ordinary skill in the art is apprised, the surface loading of capping groups may also be controlled through other approaches, such as, but not limited by stoichiometric control. Additionally, though solution approaches to capping is given in the above examples, in situ capping is also contemplated. Using in situ capping it is possible to produce a variety of surface-capped Group IV nanoparticle materials. Apparatuses and methods for in situ modification of Group IV nanoparticle materials are given in U.S. Patent Application No. 60/881,869 (filing date Jan. 22, 2007) the entirety of which is incorporated by reference.
[0042] While principles of the disclosed Group IV semiconductor nanoparticle inks have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of what is disclosed. In that regard, what has been disclosed herein has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit what is disclosed to the precise forms described. Many modifications and variations will be apparent to the practitioner skilled in the art. What is disclosed was chosen and described in order to best explain the principles and practical application of the disclosed embodiments of the art described, thereby enabling others skilled in the art to understand the various embodiments and various modifications that are suited to the particular use contemplated. It is intended that the scope of what is disclosed be defined by the following claims and their equivalence. | A method of forming an ink, the ink configured to form a conductive densified film is disclosed. The method includes providing a set of Group IV semiconductor particles, wherein each Group IV semiconductor particle of the set of Group IV semiconductor particles includes a particle surface with a first exposed particle surface area. The method also includes reacting the set of Group IV semiconductor particles to a set of bulky capping agent molecules resulting in a second exposed particle surface area, wherein the second exposed particle surface area is less than the first exposed particle surface area. The method further includes dispersing the set of Group IV semiconductor particles in a vehicle, wherein the ink is formed. | 8 |
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